DE10014480A1 - Eye refractive profile developing method for ophthalmic refractive surgery, involves developing refractive course of treatment of eye from determined corneal topography and wavefront aberration - Google Patents

Eye refractive profile developing method for ophthalmic refractive surgery, involves developing refractive course of treatment of eye from determined corneal topography and wavefront aberration

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Publication number
DE10014480A1
DE10014480A1 DE2000114480 DE10014480A DE10014480A1 DE 10014480 A1 DE10014480 A1 DE 10014480A1 DE 2000114480 DE2000114480 DE 2000114480 DE 10014480 A DE10014480 A DE 10014480A DE 10014480 A1 DE10014480 A1 DE 10014480A1
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DE
Germany
Prior art keywords
eye
data
refractive
system
topography
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DE2000114480
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German (de)
Inventor
Timothy N Turner
Charles R Broadus
Kristian Hohla
Gerhard Youssefi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Technolas Ophthalmologische Systeme GmbH
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Technolas Ophthalmologische Systeme GmbH
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Application filed by Technolas Ophthalmologische Systeme GmbH filed Critical Technolas Ophthalmologische Systeme GmbH
Priority to DE2000114480 priority Critical patent/DE10014480A1/en
Priority claimed from PCT/EP2000/010375 external-priority patent/WO2001028410A1/en
Publication of DE10014480A1 publication Critical patent/DE10014480A1/en
Application status is Withdrawn legal-status Critical

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Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B3/00Apparatus for testing the eyes; Instruments for examining the eyes
    • A61B3/10Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions
    • A61B3/1015Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions for wavefront analysis

Abstract

A corneal topography of the eye is determined by employing a slit lamp, elevation or corneal surface curvature based topography system. A refractive course of treatment of the eye is developed from the determined corneal topography and wavefront aberration and detected waveform aberration of the eye. Independent claims are also included for the following: (a) System for detecting refractive abnormalities of eye; (b) Eye refractive treatment course developing method; (c) Eye refractive aberration determining system; (d) Eye refractive treatment course developing system

Description

Technical part

The invention relates to systems for refractive eyes surgery and in particular a system for combining ophthalmic wavefront aberration data and ophthalmic logical corneal topography data to find a specific Ab generate wear or ablation correction profile.

Technical background

In the field of ophthalmology or ophthalmology great advances in development in recent years refractive treatments to correct vision defects Eye made. These techniques were from previous radial ones Keratotomy techniques are developed in which the cornea passes through Slits in the cornea were allowed to relax and transform to provide techniques such as  for example photorefractive keratectomy ("PRK"), external lamellar keratectomy ("ALK"), laser in situ keratomileusis ("LASIK") and thermal techniques, e.g. B. thermal laser ratoplasty ("LTK"). The aim of all of these techniques is to ne relatively quick, but persistent vision correction to reach.

Through the development and further developments or Ver refinement of these techniques has resulted in greater precision refractive or refractive error correction. In early treatment types, the precision of the correction was right relatively rough. A correction with a tolerance of e.g. B. plus / minus a diopter of the desired correction for Nearsightedness or myopia would be an excellent result been considered. The types of treatment were increasing further developed or refined, so that a correction more difficult or subtle defects. Nearsightedness (myopia) and farsightedness (hyperopia) can now with high precision using conventional techniques be corrected, and using excimer lasers higher order effects, e.g. B. Asphericity and uneven presbyopia (astigmatism), corrected become.

At the same time, the diagnostic tools were also used agree which correction is required, further develop celt. By using topography systems, visual impairments can be regardless of their "uniformity" determined and correct be rigged. Such techniques are in U.S. Patent No. 5,891,132 with the title "Distributed Excimer Laser Surgery Sy stem ", issued on April 6, 1999. By various new types of topography systems, pachymetry systems, wel lenfront sensors and generally by refractive errors not only the myopia, hyperopia and Degree of astigmatism can be determined, but can also  higher order rations of the refractive properties of Au be recorded.

The detection of wavefront aberrations in the human eye for intraocular surgery and for the production of contact lenses and intraocular lenses is described, for example, in "Objective measurement of wave aberrations of the human eye with the use of a Hartman-Shack wavefront sensor", Liang et al., Journal of the Optical Society of America, Vol. 11, No. 7, July 1994, pages 1-9. This technique is summarized with reference to FIG. 1. A light beam from a laser diode or another suitable light source is directed towards the pupil and strikes the retina. A beam (or wavefront as described in Fig. 1) is reflected by the retina and exits the pupil. Typically, the incoming or outgoing and the outgoing light follow a common path; the incoming light is brought into the common optical path by a beam splitter. The emerging beam is fed to a Hartmann shack detector to detect the aberrations. Such a detector has an arrangement or matrix of small lenses which break up the light into an arrangement or matrix of light spots and focus the light spots onto a charge coupling detector (not shown in FIG. 1) or another two-dimensional light detector. Each light spot is located in order to determine its shift Δ with respect to the position it would take in the absence of wavefront aberrations, and the displacements of the light spots enable the wavefront to be reconstructed and thus the aberrations to be detected by known mathematical methods. In Fig. 1, θ denotes the local averaged wavefront slope in front of the lens array and is related to the spot shift and focal length of the small lenses by θ = Δ / f, as will be apparent to those skilled in the art.

Improvements to those of Liang et al. shown tech nik are in "Aberrations and retinal image quality of the normal human eye ", J. Liang and D. R. Williams, Journal of the Optical Society of America, Vol. 4, No. 11, November 1997, pages 2873-2883 and in U.S. Patent No. 5,777,719 to Williams et al. ("Williams"). Williams be writes techniques for capturing aberrations and for Using the aberrations thus detected for eye surgery and for making intraocular and normal contact lenses.

In the international patent publication WO / 99/27334 (International patent application PCT / US97 / 21688) ("Frey") is another modification using op table polarization elements for controlling the backscatter described by the lenses in the detector array. Similar as with Williams, Frey suggests data from the Wel lenfrontsensor to use for an optical correction for to develop the examined eye. That is, the one so determined Optical correction is based on that measured by the sensor Limited opening of the cornea, e.g. B. to a circle of 6 mm, to which the pupil of the eye was dilated when the Au was measured. Outside of this range, Frey beats the use of a tapered transition area for partial ablation or ablation to make strong changes to minimize the curvature of the cornea and thereby back reduce education.

These diagnostic systems and procedures enable one Correction of both the basic effects and the effects height order, especially if you continue to sell nert refractive correction techniques are used, so that there is a possibility that someday vision defect  corrections of better than 20/20 will be the norm. It be however, there is a need for improved techniques to apply advanced diagnostic techniques in refractive Surgery.

Description of the invention

In the embodiments of a Sy according to the invention stems and the method according to the invention is a wave front aberration diagnostic tool for ophthalmic treatment or evaluation with an ophthalmic topography work stuff coupled. With the wavefront tool, refrak tive data within the pupil boundaries and through the topo graphic tool data recorded beyond the pupil boundaries. This information is then, either before or after they are used combined to provide refractive treatment generation. Preferably this treatment is for one Excimer laser surgery system.

Through further embodiments of the invention other techniques for combining wavefront and topo graphic data and for using both data records in the process treatment of refractive eye defects. At In one embodiment, the topography data is a Pre-evaluation or pre-screening based on patients based on various criteria, e.g. B. on the horn skin thickness, corneal asymmetry, and similar parameters. If the patient is a suitable candidate, the wel lenfront tool used to measure the wavefront aberration of the Eye. Then the detected wavefront but ration data used to calculate the ablation profile. This ablation profile is then related to the recorded To simulated image data of the eye, and the obtained simu ablation is also evaluated to determine whether the result (again e.g. the corneal thickness and thickness  regularity) are within the permissible guide values. Therefore are the topography data, the physical characteristics of the eye and wavefront data showing the total refraction display properties of the eye, for evaluation and generation of the ablation profile.

In another embodiment, the topography the various characteristics of the eye, e.g. B. the front and Back of the cornea and the front of the lens, through recorded a height-based topography system. Then one calculated wavefront ablation based on this topogra data using a ray tracing system derived. Then a wavefront tool captures the total wavefront aberration of the optical eye components inside half of the pupil area. Then by comparing the waves calculated based on the topography of the eye front with the through the wavefront tool inside the Pupil area captured wavefront the topographically guided, calculated wavefront based on the inner wavefront data detected half of the pupil range true ". This allows an overall wavefront and an ent speaking treatment for areas inside and outside of the pupil area are developed while the treatment lung based on the detected within the pupil area th wave front data is "tuned". Because through which he summarized the wavefront data of the total refractive errors of the opti cal eye components is detected while the compute Topography data used the topography of the wavefront may not represent certain surfaces, is therefore a good Ba by the acquired wavefront data sis provided, with respect to which the calculated wavefront is calibratable.

In yet another embodiment, extreme irregular eyes first under a course of treatment  Using the topography data generated to try gross asymmetries or irregularities in the refractive or eliminate refractive profile. If this treatment Once applied, it becomes refractive Evaluation with the topography tool and / or with the wel lenfront tool made a base for another to get refractive correction of the eye.

Similarly, it can be highly irregular Eyes can be difficult to source through a wavefront to determine the focus of the tool. The focus te can be offset so irregularly that it is difficult is to determine which focal point which eye relief cut is assigned. In such an eye, the Topography data and the ray tracing algorithm Priority position can be estimated. Then the world seizes lenfrontsensor priorities, and based on those from the Priorities calculated topography data will do neuter focus positions certain eye areas assigned. In this way, wavefront data can even can be better grasped for highly irregular eyes.

All of these different embodiments enable hence the use of both the wavefront and the Topography data to develop refractive treatments. In addition, various aspects of this embodiment can be combined or eliminated, in general these embodiments, however, alternative combinations, which is based on the development of refractive treatments possible on topography as well as on wavefront data chen.

According to further features of the invention, the topogra system preferably a height-based slit lamp top graphic tool that shows the height of the refractive surfaces in the Eye, including the anterior and posterior corneas  area, determined. Based on this data, the To photography system preferably a ray tracing method used, usa the total refractive properties of the eye so probably inside as well as outside the pupil area determine.

Brief description of the drawings

Fig. 1 shows the principles of the wavefront measurement;

Fig. 2 is a diagram illustrating combined ablation profiles developed from wavefront data and surface topography data;

Fig. 3 shows a sectional view of an eye and associated diagnostic tools that are used to determine specific refractive properties of the eye;

FIGS. 4A and 4B are flowcharts for illustrating a patient review flow and a process / data flow of a combined topography / Wellenfrontbehand development system in accordance with embodiments of the invention;

Fig. 5 shows a block diagram of a preferred shaft front sensor for use in a system according to the invention;

Fig. 6 is a flowchart showing the acquisition of iris image data and the use of the data for subsequent laser treatment;

FIG. 7A, 7B and 7C show block flow diagrams for illustrating the acquisition of iris data in conjunction with re fraktiven characteristic data, the generation of a treatment basie rend on these data and the use of Behandlungsda th in conjunction with an iris image to perform a La seroperation;

Fig. 8 is a diagram showing various features of an eye that can be used for characteristic iris data;

Fig. 9 is a flowchart showing the use of stored iris data and mapped iris data to translate or convert a desired treatment to an actual or real treatment;

Fig. 10 is a flow chart showing an alternative method in which stored iris data is used to align or align a treatment; and

FIG. 11A and 11B show display images to illustrate the method of Fig. 9.

Embodiments of the invention

Corneal surface topography systems generate surface topography data regardless of the degree of enlargement of the pill, but the area over which wavefront sensors acquire data is limited by the dilation of the pupil when the measurement is carried out. Wavefront sensors measure refraction effects of the optical elements arranged in the optical path. According to certain aspects of the invention, a corneal surface topography system measures a surface area that is larger than the dilated pupil, while a wavefront sensor measures a central portion within the pupil area. The method is shown in FIG. 2, wherein ablation profiles based on wavefront data and surface topography data are combined. Fig. 2 shows a surface topography-based ablation profile 162 , which is developed based on surface topography data. These data are also valid outside the pupil, which is shown as pupil diameter 160 . For comparison, a wavefront-based ablation profile 164 developed from wavefront data is generally only valid within the range of the pupil diameter 160 . Therefore, the two profiles using the wavefront based ablation profile 164 are shown within the pupil diameter 160 and using the oberflä chentopografiebasierten ablation profile 162 outside of the pupil diameter as a combined ablation profile 160 166th In this example, each ablation profile is first calculated from the corresponding data before the profiles are combined. Alternatively, the actual refractive characteristics could be combined by methods before an ablation profile is calculated. Height-based topography systems, e.g. B. the topography system ORBSCAN II® from Bausch & Lomb / Orbtek, Inc., Salt Lake City, Utah, are particularly advantageous in connection with the use of the wavefront sensor. In the practice of the present invention, however, other topography systems could also be suitable, e.g. B. curvature-based systems, wherein preferably more than just the front surface of the eye is measured. Other suitable system types are e.g. B. dual camera systems, which are described in example in US Pat. Nos. 5159361 and 4995716 be.

The ORBSCAN II® topography system is a height-based Slit scan topography system that simultaneously both horn skin surfaces as well as the front of the lens and iris measures. Each measured surface can be used as a map or diagram the height, inclination, curvature or refractive power the. In addition, a complete pachymetry Corneal map from the measured corneal surfaces directs. Optical path tracking calculations can be performed be applied to the visual impact of the various op table components within the ocular anterior segment to determine. ORBSCAN II® topography measurements are based on to diffuse reflections instead of specular reflections instead of the surface curvature, the surface height is precise  capture. It can be diffuse in combination with the measurement Reflections a mirror-reflected image of a placi doschen disc or a reflective target or one Target used to increase the surface slope measure, as can be seen by experts. For exemplary Descriptions of the height-based ORBSCAN II® Topography systems see U.S. Patent Nos. 5512965 and 5512966 by Richard K. Snook. The data from the ORBSCAN II® system can exactly and seamlessly into the total refraction data from the world lenfront sensor can be converted.

In addition, the data from the wavefront sensor to "Calibrate" data in the topography system the. Because the wavefront sensor detects the total refractive error in the Eye describes, the software of the topography system ei ne surface topography at any point with a (determined by a wavefront sensor) and this point correlate the assigned total refractive error. So kali The topography system data can then be used to generate an overall refractive error profile.

In another example, the data from ver various diagnostic tools can be combined to create a Ge to provide a complete model of the optical components of the eye len. For example, a corneal surface topogra fiesystem provide surface data, an ultrasound system stem could provide corneal thickness data, and a wel lenfrontsensor could provide total refractive error data len. By "subtracting" the effects of the surface data and the thickness data can therefore leave optical components behind the cornea using the different data sets be modeled.

Fig. 3 shows a cross-sectional view of the eye E with a cornea 450, a lens 456 and a retina 458th The cornea 450 has several layers, e.g. B. a cuticle or epithelium 452 and a stroma 454 . These different components, in particular the cornea 450 and the lens 456 , work together and produce an overall refractive power and a refractive property of the eye E. Several factors can contribute to refractive (e.g. wavefront aberration) errors, e.g. B. Irregularities in the cornea 450 or in the lens 456 and the distance (e.g. in the sense of a defocusing aberration) from the cornea 450 and the lens 456 to the retina 458 .

In addition, Fig. 3 shows designations for representing various types of diagnostic tools, which are particularly suitable for analyzing refraction and other properties of certain sections of the eye E. These tools can be used to provide different types of data for different sections or components of the eye E. For example, the thickness of epithelium 452 and stroma 454 can typically be determined by ultrasound techniques 460 , thereby obtaining the total thickness of cornea 450 . Various types of ultrasound technology can be used, e.g. B. a pachymetry technique or one described in US Patent No. 5293871 entitled "System for Ultrasonically Determining Corneal Layer Thickness and Shape" issued March 15, 1994.

A corneal surface topography is typically provided and analyzed by corneal surface topography systems 462 . Topography systems, e.g. B. the previous ORBSHOT ™ model from Orbtek and the System 2000 from EyeSys typically have a very high resolution, but are limited to the surface of the epithelium 452 of the cornea 450 .

A combined refractive diagnostic tool 464 , e.g. B. Orbtek's ORBSCAN II® topography system typically determines and analyzes various thicknesses and surfaces within the eye. This may include the thickness of the cornea 450 , the surface topography of the cornea 450 , the top surface of the lens 456 , the distance from the lens 456 to the cornea 450, and the distance from these front optical components of the eye to the retina 458 .

Finally, through the in Fig. 3 by the reference numbers 466 shown Be wavefront sensor, z. B. provided by the wavefront sensor 102 described above or the wavefront sensor described by Williams, data on the total refractive aberrations of the eye, which are shown as aberration wavefront profile (data) 468 . The wavefront sensor techniques are empirical in nature and relate to the characterization of the wavefront of light incident on the outside of the eye and reflected by the retina 458 instead of physical parameters of any specific optical component of the eye E.

FIGS. 4A and 4B show a Patientenflußdiagramm 500 and to develop a process / data flow diagram 550 for a treatment for a refractive eye correction for illustrating embodiments of the invention, said topography data and the wavefront data are combined. The topography system is preferably an ORBSCAN II® topography system from Orbtek, which, as discussed above, provides a height-based topography of various surfaces. In addition, the topography system can have a beam tracking module in order to calculate a wavefront based on the physical eye components determined by the topography system. However, the ORBSCAN II® topography system does not determine the physical structure of all eye components, so that an "overall refraction", e.g. B. from the manifest refraction of the patient, as "Ba sis" is determined, from which the ray tracing module of the topography system determines the total wavefront aberration of the patient's eye.

In connection with this topography tool by a wavefront tool, e.g. B. provided by the above-described wavefront sensor 102 or the wavefront sensor described by Williams, data for the refractive wave lenfront aberration is provided. These data have the advantage that the entire refractive features of the eye are determined, whereas the topography-based system may not provide the physical parameters of certain components that are useful for calculating the wavefront aberration of the patient's eye, e.g. B. the shape of the rear lens surface and the exact optical refractive features of the corneal material.

Referring to FIG 4A. In a typical evaluation and treatment first in a step 502, a Topografieun tersuchung the patient's eye made and used for screening. Because the topography system has certain parameters, e.g. B. the corneal thickness, bulge, and other physical parameters that could lead to a total rejection are rejected in a step 504 physically unsuitable eyes, so that physically unsuitable eyes are rejected, as by the rejected candidate in Step 506 is shown.

However, if the topographic evaluation shows that the physical features of the patient's eye are suitable for developing a refractive treatment process, the topographic data are then used to determine whether the eye is unsuitable for use with a wavefront tool - i.e. whether that Eye is a "difficult" or "bad" eye. In this case, the topography data can be used instead of the acquired wavefront data in order to generate a suitable treatment procedure. The patient proceeds to step 510 , where the appropriate ablation profiles are determined based on the topography data for the eye. As described below in connection with FIG. 4B, if a substantially improved "good" eye is obtained by the initial treatment based on the topography data, further treatment can be carried out based on the combined topography and wavefront data. In general, however, the treatment flow is developed using the height-based topography data starting with a "bad" eye, and then in step 512 the ablation is performed. If it is determined (step 514 ) that the result is good, a suitable patient appears in step 516. If it is determined in step 514 that the result is not optimal, another topographic examination is carried out in step 518 in order to determine whether further treatment would be useful (step 520 ). If further treatment would not be useful, the result obtained for the patient in step 522 , although not optimal, is final. If further treatment would be useful, another height-based ablation is planned in step 510 . In this last process, if the topography evaluation in step 518 shows that the eye is no longer a "bad" eye, a return can be made to step 508 , where a wavefront-based treatment process is developed.

Although in connection with the above embodiment form an exclusively topography-based ablation for "Bad" eyes have been discussed in other ver drive wavefront results even for "bad" eyes be applied. Other treatment procedures can be irregular  moderate eyes, unlike standard eyes. For example, it may be desirable to use a multi-level cor correction for such "bad" eyes as in the associated document "Method and Apparatus for Multi-Step Correction of Ophthalmic Refractive Errors " is discussed below this patent application.

There can be a time period between the evaluations to brush. The stromal tissue that is incised when Valves are created in a LASIK process, nor heals not sometimes, so that a flap is easily attached again can be lifted. After a normal edema on the The patient’s eye has regressed after a few days, the patient can then be evaluated firstly to determine whether his eye is good or bad, and two whether a further treatment would be advantageous.

It is assumed that the patient does not have a "bad" eye in step 508 , which is determined either after the initial evaluation in step 504 or possibly after the evaluation in step 518 . In this case, a combined wavefront topography treatment process is developed. In step 524 , a wavefront examination is performed on the patient's eye. This is preferably carried out using a manifest refraction (ie without widening the eye), although a cycloplegic refraction can be used (ie with widening the patient's eye, which corresponds to a parallelization of the accommodation flexibility). In step 526 , the detected wave front refraction is compared to the patient's actual subjective refraction. If there is a significant difference, treatment may be terminated at the doctor's request, resulting in a rejected candidate in step 506 . Certain differences, as described in connection with Figure 4B, can be used to calibrate and align the two data sets. For example, second order aberrations (ball and cylinder) can be scaled to a target value to match the refraction or refraction data or for other purposes.

If the acquired wavefront data suitably matches the patient's subjective refraction, processing instead proceeds to step 528 where the ablation is scheduled. As discussed below in connection with FIG. 4B, this can be generated in various ways, e.g. B. based exclusively on the acquired wavefront data or on a combination of the acquired wavefront and topography data. Processing then proceeds to step 530 where the ablation is performed. Then a positive result in step 532 results in a suitable patient being obtained in step 516 . If a negative result is obtained in step 532 , the patient may be further evaluated in step 510 for height based ablation profiles, as discussed above.

In the overall treatment process, however, is by the topographic data received a physical eye feature Initial assessment of the patient for treatment is possible light. Then either only topography data or topography data and acquired wavefront data in combination nation used the overall treatment process for the Au to develop.

Instead of the topography system, different ones can be used their topography system types or systems for developing phy characteristics of the eye (e.g. pachymeter and similar sy steme) can be used. In addition, the wavefront can tool has several wave front detection systems sen, e.g. B. a Hartmann shack described by Williams  System, scanning systems, or various other types of world lenfront acquisition systems.

FIG. 4B shows a typical process / data flow diagram 550 associated with the patient flow diagram 500 of FIG. 4A. The process / data flow diagram 550 of FIG. 4B particularly relates to a typical data flow for topographical data and acquired wavefront data for developing a refractive treatment process. As described above in connection with FIG. 4A, the data flow begins in step 552 with a topography examination, from which this examination, which is discussed for simplification in step 554 , topographic data (preferably elevation data for several surfaces) are obtained. The data can be obtained Manual or automatic, and in combination with other data, to determine whether the patient's eye is suitable for refractive treatment, a cornea that is too thin, an irregular eye, or other criteria may result in patient rejection , which is shown as step 556. If the eye is suitable for treatment, the topography data is passed to step 558 to determine whether the eye is simple or difficult. This determination can also be based on various criteria and automatically, manually or in combination, e.g. with an evaluation of the displayed topographer Data is provided by the doctor. If it is determined in step 558 that the eye is a "difficult" or "bad" eye, the data flow proceeds to step 560 where the topography data is e.g. B. in conjunction with a qualitative investigation based standard visual acuity data to develop a refractive standard treatment process based on the height data. Typically, such a height-based ablation profile is based only on the refraction of the patient's eye and the height map of the surface of the eye, in order to determine both a desired postoperative spherical corneal refractive power and an ablation profile by which this refractive power is obtained. Such a height-based system could, for example, take into account biconvex or lens astigma if the lens profile is detected by the height-based system. This topography-based method can be suitable if reliable data cannot be provided by a wavefront sensor due to problems with the patient's eye. Such problems can be, for example, irregularities and various other conditions which affect the detection of the overall refractive wavefront.

As part of the development of this refractive treatment a suitable laser shot pattern or a developed other refractive treatment technology, the Treatment simulates and the resulting corneal profile The change is presented to the doctor. Because the initial is known from the topography data, and because the effect of the refractive treatment process be is known, the resulting profile, the thickness and physical topography features of the eye to some extent predictable and can be presented to the doctor. If the doctor decides based on this representation, the entire course of treatment can not continue Processing to be ended.

If the doctor decides to continue treatment, the doctor ablates at step 562 . The treatment process developed in step 560 can be transmitted to the laser system in various ways in step 562 , or the calculation can be carried out as part of the laser system. U.S. Patent No. 5,891,132 to Hohla describes a distributed system in which treatment procedures are transferred from place to place to better utilize resources; a similar system can be implemented to direct the various refraction data and ablation profile data in the system described. The ablations are performed in step 562 according to a PRK or LASIK procedure or other treatment procedure. In step 564 , the results are evaluated. This evaluation can be based on a topography evaluation or on an evaluation of a detected wavefront or on other refractive evaluations. If the visual acuity obtained is within the desired limits, the treatment process for the patient is ended, as shown in step 566 . Subsequent evaluations can be used to monitor regression or other changes towards better or worse.

If it is determined at step 564 that the results are not optimal, the patient can be evaluated at step 568 for further treatments. Again, this can be based on the same data that was acquired in step 564 or possibly on additional data. For example, in step 564 the manifest refraction of the patient can be determined using eye diagrams and topography data can be acquired. In step 568 , this data is analyzed and, if necessary, further wavefront data can be acquired. The data is then evaluated to determine if further eye treatments are possible. At this point, if no further treatments are possible, the patient's visual impairment has been corrected as much as possible so that the treatment process ends in step 570 . If further treatments are possible, a height-based ablation is planned again in step 560 . Alternatively, and not shown, if the evaluation results obtained in steps 564 and 568 indicate that the eye is no longer a "difficult" eye, a combined wavefront / topography treatment procedure could be developed starting at step 572 .

The data recorded in each step can be transmitted or forwarded for evaluation. In other words, when evaluating the results in step 564 , any acquired data could be used in step 568 to determine possible further treatments. It may be desirable to allow a period of time to elapse before the eye has further stabilized before final data is acquired for a next course of treatment, but in general any acquired data can be considered a future processing step. It is also desirable to keep this collected data for clinical studies and for the evaluation of empirical results. As a database, this data forms an excellent source of clinical information on the actual effects of certain treatment procedures on the eye, so that nomograms can be compared and even better refractive corrections for future patients are made possible.

Step 572 begins if the eye was not assessed as difficult in step 558 , or possibly from step 568 if a "simple" eye was obtained through previous treatment. In this embodiment, beam tracing is first performed with respect to ORBSCAN II® topography data in order to develop a calculated wavefront. This calculated wavefront is based more on physical topographies of optical eye components than on a wavefront actually detected by a wavefront tool. This calculated wavefront enables the calculation of predetermined wavefront focal points at which the actual wavefront data are acquired. As a result, the acquired wavefront data can be better evaluated, and the wavefront tool can be used to use various wavefronts. In step 574 , the centroids are actually calculated, and this data is preferably supplied to the wavefront tool in step 576 to assist the wavefront tool in determining the source of actual beam spots. In many cases, the detected wavefront priorities will be sufficiently regular so that the calculated wavefront data is not required, but the interaction of the two systems in steps 574 and 576 does not allow greater flexibility in using the wavefront tools to determine a refractive correction .

The wavefront examination in step 576 detects wavefront data within the pupil region of the patient's eye in step 578 . In contrast to cycloplegic refraction, many physicians generally prefer a refractive correction of a manifest refraction, so that the pupil area can be relatively small when the wavefront data are acquired, but the complete refractive error of the pupil area is highly precise due to this small data area can be obtained. This data is then made available again in step 580 for the topography data, the topographically based, calculated wavefront being "calibrated" or "adjusted" based on the actually detected wavefront. Because a wavefront based on an ORBSCAN II® system is an analytically calculated wavefront, whereby the topography system does not know all the physical parameters of the eye, the wavefront data acquired within the pupil area can be used to compare and adapt the topographical data within the pupil area . Based on the adjustment required within the pupil area, the topography-based, calculated wavefront data outside the pupil area are then adjusted accordingly. This enables a comparison based on a “detected wavefront” with the calculated wavefront based on the ORBSCAN II® system. Alternatively, e.g. B. using a darkened room, a wavefront from a larger pupil len range can be determined without inducing cycloplegia or accommodative paralysis. In this case, the data could be used without the topography data or in combination with the topography data.

In addition, the actually detected wavefront compared with calculated wavefront data in order to to ensure that there are no rough dis there are any discrepancies. Such discrepancies would for example, a strong irregularity in the optical Show eye components by topography or Wavefront data are not collected and could result in that it would be suggested not to continue treatment put. For example, the topography data shows a fair amount Lich uniform lens. The correction of an eye with A highly uneven lens could cause problems lead if this lens later z. B. as part of a star or cataract surgery would be replaced. Under the prerequisite tion that the wave front system within the Pu pill area and the wavefront through the topo graphics system are calculated close to each other (and are close to the subjectively determined refraction), although their scale may be different, the Be progresses course of action continues. Therefore, all of these data sources are for mutual cross-verifications or cross-checks usable.  

In step 582 , the wavefront measured by the wavefront tool is combined with the calculated wavefront based on the ORBSCAN II® system. This can be done in a number of ways. Either the ORBSCAN II® wavefront can be adjusted or scaled based on the actually measured wavefront data, as discussed above, or the measured wavefront can be used within the pupil area and the calculated wavefront outside the pupil area. However, this data is combined, and then the overall wave front is fed to the ablation software in step 584 , which calculates an appropriate treatment procedure for correcting the wave front sensor. This process can be fully automated or possibly partially automated and partially manual.

Based on this calculation, a treatment procedure for performing the ablation is provided in step 586 . This treatment flow is compared to a pure height-based treatment flow (calculated, for example, in step 560 ) to ensure that the results are not highly different, which could indicate problems with the execution of the eye treatment. This step also serves as a counter-control. In addition, a simulation of the treatment process with respect to the topography determined by the topography system is preferably carried out in order to determine and display a resulting topography and to verify that the resultant parameters of the treated eye are within acceptable standards.

The ablation is then performed in step 590 . After the ablation has been performed, a similar post-operative follow-up treatment is carried out in step 564 , and subsequent treatment sequences can be carried out based on the topography or the detected wavefront.

That through the topography system, the wavefront tool and rake used the ablation profile generation tool system can be a separate system, one in a network bound system, a combined system or a combination be a nation of it. In a typical implementation both the height-based ORBSCAN II® topography tool and the wavefront tool is also a common computing unit use that retrieves data from both tools and data on a single screen. Alternatively, could however, each tool has its own computing system and its egg Show genes display, with data to and fro become. In addition, the course of treatment could be the same chen system, on an independent or autonomous person nalcomputer or generated within the laser system itself become. There are also other distribution alternatives Calculations and display representations possible.

In the practice of the present invention, ver different wavefront techniques and associated fixtures sensors are used, and the description below is intended for purposes of illustration and not to limit understood meaning. As described above, the Hartmann Shack type sensor uses a lens order for developing an image from several light spots on a detector. The shifts in the light spots are related to local slopes of the wavefront. By the measure of how this with the first derivative of the Zerni ke polynomials match, are the wavefront aberrations data determined. The lens arrangement makes a "paral lele "retinal light spot image point measurement provided. Egg ne other technique is a scanning or scanning technique, according to which a collimated beam or laser onto the retina fo  kissed and scanned over the eye. The reflected Retinal image light spot is then again on a detector pictured. For a perfect eye, everyone would be reflected Image light spots regardless of the scan position on the Drop the cornea onto the center of the detector. The postponement" or the "offset" of the image light spots on the detector is measured as a function of the scan position on the cornea sen, and the slope of the wavefront becomes similar to that of Hartmann-Shack lens technology. By another re technology, input beams are provided, which Go through the eye and be focused on the retina. The reflected light spots are abge on a detector forms, and the "shift" becomes emmetro pen eye determined. However, all of these techniques are the same in that they only be an actual wavefront measurement regarding the total refractive error of the eye from the network Provide skin to the surface. Other wavefront techn ken are known or could be developed.

Calculation of a wavefront aberration from topography data and appropriate treatment

As described above, ORBSCAN topography data can be used to both calculate a wavefront and develop a course of treatment. One technique by which this is accomplished is a ray tracing or ray tracing technique. A corrective corneal ablation pattern can be determined from the geometry of the ocular refractive surfaces and the refractive indices of the media separating them. This is suitably carried out by finding the wavefront required for stigmatic imaging by a reverse beam path. For example, it is assumed that the corrected system serves to generate a refraction-limited image on a known image plane (e.g. on the retina). A point source is theoretically arranged at the intended image position (in the following figure F). Rays emanating from this source are tracked out of the system (ie in the negative z-direction), first through a modeled lens and then through the measured cornea. If the optical system is refractive limited and the focus is at F, the emerging wavefront M will be planar or planar and the emerging rays will be mutually parallel (because they are all oriented perpendicular to the planar wavefront).

Optical path length difference (OPD): If the emerging wavefront is not flat, the corrective ablation is calculated so that the emerging wavefront becomes flat. To achieve this, the optical path length ϕ (x, y) of each beam from the point source F to a reference plane M lying outside the front corneal surface and arranged perpendicular to the intended line of sight is first calculated. The optical path length, which is proportional to the time it takes for the light to travel from F to M, is given by:

where s is the arc length measured along the beam and n (s) is the refractive index of the medium. Beam coordinates (x, y) are defined by beam cuts with the external reference plane. The following figure shows a cross section through the optical path length function for both a myopic and a hyperopic eye. The optical path length is always positive.

The purpose of ablative correction is to flatten the wavefront in a central region (by -Δϕ) by flattening the front surface of the cornea (by Δz). If corneal material is to be removed in the process, the optical path length difference (OPD) Δϕ from the desired plane to the actual wavefront must always be positive. If a plane wavefront is defined by ϕ p , the following applies:

Δϕ ∼ ϕ (x, y) - ϕ p (x, y) (2)

Invariant beam model: How must the cornea be removed to reduce its optical path length difference (OPD) to zero? A rough estimate of the reduction in the optical path length difference can be made by assuming that the beam path does not change due to the ablation. Then, by removing the cornea over a distance s 1 along a beam, the refractive index of the cornea (n C = 1.366) is effectively replaced by the refractive index for air (n A = 1,000). Suitably, the ablated length along the beam needs to be converted to an ablation or ablation depth in the z direction, which is achieved by an eta factor η 1 defined below (the form of η 1 is derived in the next section). Under this condition, the ablation depth for the invariant beam model is:

is.

If z is positive in the eye, remove it of corneal material always has a positive ablation depth Δz required.

Planar environment model: For the next best approximation of the ablated optical path length difference (OPD) it is assumed that the corneal surface is flat in a narrow environment around the refracted beam and that the cornea surface alignment remains unchanged due to the ablation. In this case, the airways of the preoperative jet R 1 and the postoperative jet R 2 are parallel but offset, as shown in the following figure:

The optical path length difference (OPD) between the beams R 1 and R 2 depends only on the refractive indices of the two media and on the distances s 1 , s 2 and s 3 . The final solution will be linear because these three lines are all proportional to Δz:

Δϕ = ϕ (R 1 ) - ϕ (R 2 ) = n C s 1 + n A (s 3 - s 2 )

Because the optical path length difference (OPD) is directly proportional to the surface offset Δz, a set of eta factors is defined as follows:

is.

To calculate the Eta factors, vectors S 1 and S 2 and the surface tangent T connecting them are defined. Below are 1 and 2 unit length direction vectors of the straight portions of the beam that is broken at the posterior corneal point P and at the anterior corneal point A.

The vertical offset of the refractive surface δ is proportional to S 1 , S 2 and Δz. In the following, the unit surface normal (which is positive in the z direction) of the refractive surface, and = (0, 0, 1) denotes the unit vector defining the z direction of the coordinate frame.

These relationships can be solved for the eta factors η 1 and η 2 :

In order to calculate the final eta factor, the S 3 - beam vector is defined, with S 3 - T lying in the reference plane M and thus being arranged perpendicular to the surface normal vector of the reference plane. (Typically, the reference plane is arranged perpendicular to the z-axis, so that = is. Nevertheless, a solution is given for the general case).

Dissolving according to s 3 results in:

Substitution in the OPD formula finally results in:

This solution differs from the previous one by the insertion of the beta factor β, which is approximately the value one Has. This correction is very effective because the Be ta factor a simple function of the beam vector directions is calculated during the initial ray tracing were. The next higher approximation by which the local Curvature of the corneal surface would be considered more expensive. It will also because the ablation will in principle shifts the broken beam by a small amount difficult to calculate the exact analytical result.

Iterative solution: Therefore iterative solutions are required for certain points. It makes sense to use the result of the plane model in an iterative recalculation of the beam tracking solution. The following method distinguishes between a physical optical path length difference, which is calculated with respect to the plane wavefront ϕ p , and an iterative optical path length difference, which is measured with respect to the iterative target wavefront ϕ G. The iterative optical path length difference (OPD) is only used temporarily during the iteration process. Only the physical optical path length difference is physically relevant.

Initial steps

  • 1. Given the initial front surface z I (x, y) and all other surfaces (measured and modeled), carry out a reverse ray tracing from F to M and calculate the initial function ϕ I (x, y) of the optical path length of the eye using equation 1.
  • 2. Construct the area of the optical path length for the iteration target ϕ G (x, y). This surface is flat in the middle (ie ϕ G is identical to ϕ p in the middle), but can be curved around the circumference in ϕ I (x, y) in order to obtain a smooth or even transition area. Alternatively, the transition area can be calculated later with respect to the iteration target ablation surface z G (x, y).
  • 3. Calculate the initial iterative optical path length difference (OPD) with respect to the iteration target, through which a realizable ablation is obtained: Δϕ I (x, y) = ϕ I (x, y) - ϕ G (x, y).
Iteration steps

  • 1. Calculate approximate ablation depth Δz using of equation 2.
  • 2. Fit the new front surface to z (x, y) + Δz (x, y).
  • 3. Interrupt iteration if Δz is small for all (x, y) is.
  • 4. Calculate end portion of the reverse ray tracing from P to M new and calculate the new optical path length ϕ (x, y) using equation 1.
  • 5. Calculate corrected optical path length difference (OPD) with respect to the iteration target (the corrected optical path length difference can be positive or negative):
    Δϕ (x, y) = ϕ G (x, y) - ϕ (x, y)
Final steps

  • 1. If necessary, create a smooth or even transition (with minimal change in curvature) in the iteration target ablation surface z G (x, y). The result is the final ablation surface z F (x, y).
  • 2. Calculate the final ablation depth, which can never be negative: Δz F (x, y) = z F (x, y) - z I (x, y).
  • 3. Recalculate the end portion of the reverse ray tracing from P to M and calculate the final optical path length ϕ F (x, y) using Equation 1.
  • 4. Calculate the final uncorrected optical path length difference (OPD) with respect to the perfect plane shaft front: Δϕ F (x, y) = ϕ F (x, y) - ϕ p (x, y).

This procedure is for illustration and it could other techniques are used.

Wavefront sensor

Fig. 5 shows a block diagram of a preferred Wel lenfrontsensors 300th The wavefront sensor 300 operates similarly to the Williams wavefront sensor, but has certain features that make it particularly suitable for receiving iris data and for focusing the focus of light spots on a sensor used to determine the wavefront aberrations of the eye. In general, the wavefront sensor 300 focuses or scans light (typically from a laser) on the retina of an eye and then analyzes the image returning through the lens and cornea optics of the eye (e.g. backscattered from the retina) and imaged onto a lens arrangement fo kissed light. Based on optical aberrations in the optical components of the eye, the system develops an overall wavefront aberration analysis from the returning light. In general, in order to perform the analysis, virtual images are generated on a sensor of the lens camera from the returning light by a lens camera. From these images, the wavefront sensor 102 develops a wavefront aberration card in order to show which corrections of the optical components of the eye are required through which normal vision (emmetropia) or approximately normal vision is obtained.

In order to suitably align the patient's eye E, two 660 nm laser diodes 302 shown in FIG. 5 can be aligned obliquely to the eye E. If light spots from the laser diodes 302 on the patient's eye E are suitably aligned by aligning the wavefront sensor 300 (or 102 ), the output beams of the laser diodes 302 (or the optical elements for aligning these beams), the patient, or otherwise in a single manner Light spot are combined, the eye E is arranged in or approximately at the precise focal point distance from the wavefront sensor 300 (or 102 ). Alternatively, the patient's eye E can be appropriately aligned by a doctor, technician, or other medical professional by visually viewing an iris image of eye E to find the correct focal point distance from wavefront sensor 300 and to reduce overall exposure of eye E. In this case, laser diodes 302 are not required. A light source or eye illumination 304 provides light for a pupil camera 328 described below.

Once the eye E is properly aligned, it receives light from a light source 306 (e.g., a laser diode, such as a 780 nm laser diode) along an optical path to the eye E. Preferably, the laser diode 306 has more than an adjustable output power (i.e. it works in two or more power modes), a lower power for the alignment and the initial focusing and at least a higher power for generating a multi-spot or multi-point image in a sensor (e.g. a lens camera ) 312 as described below. For example, typical lower and higher powers are 0.5 µW and 30 µW, respectively. These performance values depend on several factors, e.g. B. because of how long the laser diode 306 should be operated at a higher power.

A portion of the beam from laser diode 306 is next reflected by a beam splitter 308 (e.g., with a light transmittance of 80% and a reflectivity of 20%). The reflected beam passes through a polarization beam splitter 310 that improves the signal-to-noise ratio (or signal intensity) of the light scattered back from the retina of the eye, which is ultimately captured by lens camera 312 , as discussed below. The beam splitter 310 polarizes the light received by the laser diode 306 and generally transmits light that is linearly polarized in one direction and reflects light that is not polarized in that direction. The polarized light then passes through a reciprocating or telescopic prism 314 which is used to adjust the focus of the light from the laser diode 306 to the retina of the eye E, at which point the lens retracts from the retina Light will be focused correctly or almost correctly. The light from the telescoping prism 314 is reflected by a mirror 316 , passes through a beam splitter 318 (e.g., having 20% reflectivity and 80% light transmittance), and then a λ / 4 plate or wave plate 320 . The λ / 4 plate 320 is aligned so that essentially circularly polarized light is generated from the linearly polarized light. The meaning of this will become apparent in the discussion below of the light (the "returning light") scattered back from eye E to polarizing beam splitter 310 .

After the light has passed through the λ / 4 plate 320 , it is focused on the retina of the eye E. The light is backscattered or reflected by the retina, and the backscattered light spot on the retina then passes through the optical components of the eye, e.g. B. the lens and the cornea. On the way back, the circularly polarized light is retarded by the λ / 4 plate 320 in order to obtain light which is relative to the incoming linearly polarized light which is generated on the first pass through the λ / 4 plate 320 , as discussed above, is vertically linearly polarized. A portion of the perpendicularly polarized light then passes through the beam splitter 318 , is reflected by the mirror 316 , passes back through the prism 314 , and then returns to the polarization beam splitter 310 . At this point, the light is fully or largely polarized perpendicularly so that it is substantially reflected by the polarizing beam splitter 310 and then reflected by a mirror 322 in a lens imaging camera 312 . To direct a portion of the returning light into an adjustment or alignment camera 323 , as discussed below, the λ / 4 plate 320 can be tilted and / or rotated (e.g., rotated about 5 degrees) in its optimal orientation become). In this implementation, the light received by the alignment camera 323 would be polarized substantially perpendicular to the returning light. Within the scope of the present invention, various methods of supplying the returning light to the alignment camera 323 are also conceivable for an inclination and rotation of the λ / 4 plate 320 from its optimal orientation, e.g. B. Changes in optical path and optical components of the wavefront sensor 300 (or 102 ). For example, instead of the mirror 322, a device with controllable light transmittance and reflectivity could be used for who, e.g. B. a liquid crystal device, and the alignment camera and any optical focusing elements can be positioned so that they receive a portion of the light transmitted through the controllable device. In such an implementation, the beam splitter 308 would be unnecessary and the light received by the controllable device would have substantially the same polarization as the returning light or a parallel polarization.

The lens camera 312 is preferably a Ladungsspei cherbaustein (CCD) camera, e.g. B. A model TM-9701 camera manufactured by Pulnix with a small lens array 324 , although different cameras and lens array 324 analog, other optical scanning or scanning components could be used (including optical components separate from a camera ). For example, a camera of the ICX 039DLA type from Sony Corporation can be used for the lens camera 312 and the pupil camera 328 . The lens arrangement 324 generates virtual images on the light detection element (eg on a CCD arrangement) of the lens camera 312 from the returning light reflected by the mirror 322 . The λ / 4 plate 320 can help reduce the amount of unwanted scattered back or stray light to improve the signal intensity or contrast of the virtual images. The lens assembly 324 focuses portions of the light that initially passed through the optical components of the eye E so that the refractive wavefront aberration effects of the eye E can be determined, similarly as described by Williams. In this regard, once the wavefront aberrations and thus the phase error of the eye E have been determined, they can be converted into a required ablation profile in order to, with suitable reference to parameters of the eye E (e.g. the refractive indices of the components of the eye E and / or other parameters) to remove corneal tissue and to correct or improve visual defects. One technique for determining a suitable profile is simply to scale the wavefront data so that the scaled data essentially corresponds to the amount of tissue to be removed from the patient's cornea. Lasersy systems can then remove this tissue profile from the cornea. Markings on the eye E can be used to aid the alignment of the eye E during the acquisition of the wavefront sensor data.

The lens arrangement 324 is preferably an arrangement of approximately 25 × 25 small lenses with an area of 600 μm 2 each, e.g. B. Model 0600-40-S, manufactured by Adaptive Optics Associates, Incorporated. The small lenses are smaller than the lenses described in the aforementioned U.S. Patent No. 5,777,719 and used in other systems, which is made possible by the greater light intensity of the light supplied to the lens camera 312 obtained by components of the wavefront sensor 300 to be discussed below becomes. The optical path of the wavefront sensor 300 shown in FIG. 5 may also include lenses 326 (e.g., four lenses) and apertures or openings 327 (to allow changes in beam size) that are typical of the illumination, imaging, and focusing optics and may also represent other possible optical elements that are omitted for clarity. For example, in one embodiment of the invention, the focal length of one or both of the lenses 326 near the telescopic prism 314 can be changed, possibly shortened, to allow for a smaller width of the beam entering the lens assembly 324 . In another embodiment, the diopter measurement range possible by the wavefront sensor 300 (or 102 ) can be changed, for example, by appropriate selection of the lens 326 in front of the laser 306 to adapt to the natural poor sight distribution in the general or in a selected population of patients to obtain. One method to achieve this is to arrange lens 326 (e.g., a 5 diopter lens) in front of laser diode 306 so that the laser beam is no longer parallel. This provides a certain diopter offset that can be used to check the patient's eye through the wavefront sensor 300 (or 102 ). In one non-limiting example, the diopter range can be modified from a symmetrical range from -8 to +8 diopters with a symmetrical structure to an asymmetrical range from -13 to +3 diopters with an asymmetrical structure, as will be appreciated by those skilled in the art. This can be achieved without changing the size of the telescoping prism 314 (or other adjustment or balancing device) and / or parameters of the optics or the optical elements.

As an alternative to the position of the lens 326 , a lens 338 could be moved in the way to the lens camera 312 . Multiple positions within the path to the lens camera 312 can be used to adjust the overall range of the wavefront sensor 300 . By using the lens 326 or 338 , which can be moved into and out of a designated position, the "stroke path" required for the telescopic mechanism is reduced. In addition, laser diode 306 will typically have an "astigmatism" of its own. This can be adapted to the astigmatism typically found in the patient's eye E, as a result of which the overall area of the wavefront sensor 300 is enlarged. In particular, such an astigmatism is "adjusted with the rule" with which a patient's astigmatism is typically found, and the software of the lens camera 312 and the corresponding wavefront sensor 300 can take this self-astigmatism into account in order to provide an even larger range of determinable astigmatisms.

In the illustration, a pupil camera 328 receives z. B. 20% of the light reflected by the beam splitter 318 . The pupil camera 328 preferably generates the iris image data 132 for the iris image 136 through a control system (not shown) that is the same or similar to the control system 156 discussed below in the discussion of alignment or matching methods. For a comparison, data from the lens camera 312 is processed and finally provided as aberration data 130 .

The pupil camera 328 is arranged in the optical path between the eye E and the telescopically movable prism 314 , so that the pupil camera 328 focuses on the pupil and the iris of the eye E regardless of changes in the focal length of the rest of the system for focusing on the retina can be. Thus, the pupil camera 328 can be independent of the depth of the eye E and the corresponding distance from the retina to the iris of the upper surface of a clear image of the eye E produce.

Focus adjustment camera

The wavefront sensor 300 also includes the alignment or alignment camera 323 which takes an image of the backscattered light spot on the retina of the eye E from a beam splitter 332 (e.g. with a reflectivity of 50% and a light transmittance of 50%) receives. The alignment camera 323 is arranged in the path of the optical elements that focus light onto the retina of the eye E, and is independent of the lens camera 312 . The adjustment camera 323 makes it possible to precisely determine when the light spot striking the retina from the laser diode 306 is in or approximately in focus, and therefore supports the determination of when the light scattered back from the retina is in or approximately in the focus of Lens camera 312 is located. The adjustment camera 323 shows the light spot on the retina, which (as in Williams) is the source for the focus signals, and the light spot can be examined automatically when it is most sharply focused in order to focus the virtual images as sharply as possible To enable lens camera 312 . No alignment camera has been used in conventional systems. Such systems only use the lens camera to support the focusing of the light on a retina and the backscattered light on the lens camera. The problem with this technique is that the portion of the wavefront scanned by a single small lens of a n-lens array of individual light spots or spots on the camera sensor with at most about 1 / n of the total energy (or power) of the returning backscattered light generated before entering the lens camera. This unnecessarily exposed the retina (or the eye) to high levels of light energy (or power). As will be appreciated by those skilled in the art, the present invention can reduce the total exposure of the retina (or eye) compared to these conventional systems because the light energy (or power) received at the alignment camera 323 is only about the light energy (or -performance) which must be received on a single small lens of the lens arrangement. The adjustment camera 323 is used to control the focusing of the light observed from the laser diode 306 onto the retina directly, while the La serdiode is operated in its lower power mode 306th The alignment camera 323 therefore supports the sharpest possible focusing of virtual images on the lens camera 312 , while the laser diode 306 is operated in its lower power mode. This allows the light transmittances of the polarizing beam splitter 310 and the beam splitter 308 , the reflectivity of the beam splitter 332, and any inclination or rotation of the λ / 4 plate 320 from its optimal orientation to be taken into account to allow some of the returning light to be directed to the alignment camera 323 is returned.

As discussed above, the alignment camera 323 is used to ensure that the light spot on the retina is as sharp as possible. That is, the correct settings of the telescope mechanism of the prism 314 as well as the orientation of the patient are checked. Based on these settings and on the orientation, a signal can be generated (e.g. from the alignment camera or from a control system, e.g. from the control system 156 in FIG. 7C) to cause a patient to manually check the readings or start the patient measurement or examination automatically. Such functions also enable an increased light intensity to be supplied to the lens camera 312 only for the duration of the measurements or examination and not during the focusing and adjustment period discussed above.

In the lower power mode, the laser diode 306 is set to a power low enough to prevent damage to the retina of the eye E, e.g. B. to 0.5 µW. The use of the alignment camera 323 in the control system to support the focusing of the laser beam of the laser diode 306 on the retina can be done in several ways. For example, the size of the light spot on the retina can be minimized, or the intensity of the light spot on the retina can be maximized by adjusting the position of the telescoping prism 314 in the optical path of the wavefront sensor 102 until the light spot is as small as possible. The position of the telescoping prism 314 defines a "baseline or reference line" of the degree of myopia or hyperopia of the diopter correction that is required to initially correct lower order optical refractive aberration features of the eye E. It is useful to ensure that lasers 302 are aligned at an angle to laser diode 306 that overlap their respective light spots on the retina (or by other methods, e.g., manual or visual inspection obtained alignment of the patient's eye) in conjunction with the adjustment of the position of the telescoping prism 314 while determining the baseline or reference line level of the myopia or hyperopia error or the myopia or hyperopia correction.

Once focus is achieved, laser diode 306 is set to a higher power mode for a very short period of time. For example, a power of 30 µW with a light spot size of 10-20 µm on the retina can be used for a period of 400 ms. Although a higher intensity could damage the retina if it were maintained for a longer period (e.g. more than 100 s), such a short impulse is harmless. By the short pulse, however, the intensity of the individual light spots on the sensor of the lens camera 312 is significantly increased, so that by the combination of the multi-power laser diode 306 , the alignment camera 323 , the lens arrangement 342 and the lens camera 312 a higher signal intensity or lens images with a higher Contrast can be obtained by the lens camera 312 than in other systems. The higher power mode of the laser diode 306 enables the use of individual small lenses with a smaller cross-sectional area in the lens arrangement 324 in comparison to other systems.

Once the data from the lens camera 312 is provided, it can be used directly via Zernike polynomials to generate the wavefront aberration data, or the wavefront aberration data can be calculated as the average of a series of exposures. For example, the system can use five "shots" and then either the captured data or the corresponding Zernike data can be averaged. In addition, widely distributed "shots" can be separated out. In the system described, the five "shots" are preferably used, and the wave front aberration data is determined as the average calculated wave front aberration.

It will be apparent to those skilled in the art from the present description that various components can be used to replace components used in wavefront sensor 300 and that various optical configurations are possible to form other embodiments of the invention. For example, the laser diode 306 can be provided by a high-intensity, collimated light source or by several light sources, e.g. B. a low and a high performance light source to be replaced. The alignment camera 323 can be arranged in the path of the mirror 322 , and the lens arrangement 324 of the lens camera 312 can have a smaller or a larger number of small lenses as desired or according to the design. It is also apparent to those skilled in the art that all of these components are generally controlled by a control system, e.g. B. a microcomputer, who controls the. A wide variety of other configurations are possible within the scope of the present invention.

In the practice of the present invention need information from various diagnostic measurements with each other and also with the eye drawn by the laser led ablation profile. On the Fachge There are various methods for achieving this Alignment known, and any of these methods can in the practical application of the present invention be applied. Matching procedure using a bil of the iris of the eye (or part of the iris or other characteristic eye characteristics) are present prefers.

Using iris data to match the laserbe action

Fig. 6 shows the general flow of a method of using an embodiment of a system according to the invention. In block 10 , the iris is mapped in connection with the acquisition of refractive data using a diagnostic tool. This illustration and the use of the diagnostic tool can be of various types. For example, the tool can be suitable for laser treatment z. B. in the form of a corneal surface topography system for determining a corneal or refractive profile. Or it can be used immediately before the refractive operation. In any case, the imaged iris or a representation of the iris is held with the data generated by the diagnostic tool.

A treatment is then developed in block 12 based on the data provided by the diagnostic tool. For example, this treatment can treat some degree of myopia and uneven astigmatism. This treatment may, for example, be a treatment that is developed using the algorithms described in PCT / EP95 / 04028 entitled "Excimer Laser System for Correction of Vision with reduced Thermal Effects", published on April 25, 1996, wherein a rasterization algorithm for modifying a corneal profile is provided in conjunction with the distributed system described in US Patent No. 5891132 entitled "Distributed Excimer Laser Surgery System" issued April 6, 1999. However, this treatment is standardized to a stored representation of the iris image. This allows subsequent modifications of the treatment to be normalized to subsequent iris images based on additional diagnostic tool data.

In addition, the treatment itself is preferably compared to the patient's iris. This takes place in block 14 , where the laser target and the treatment pattern are normalized to the image of an iris of the patient to be treated. This standardization can be a very general standardization, e.g. B. translation of the laser target to a suitable point, or a more complicated normalization, e.g. B. by Rota tion or even scaling and tilting the treatment to adjust the iris image that is provided to the laser system.

Then the laser treatment in step 16 is carried out. During the laser treatment, the system can periodically or even continuously adapt the iris data to the stored representation of the iris data, that is, track the patient's eye.

FIGS. 7A, 7B and 7C show the general flow of determining refractive data, normalizing to the iris image, generating a course of treatment and on closing applying the treatment procedure in an OF INVENTION to the invention system. According to the invention, refractive features of an eye to be treated are determined by a corneal topography system 100 and a wavefront sensor 102 . Both devices generally provide data that represent refractive features of the eye. In addition, a workstation computer or a computing unit 104 is shown, which is used to generate a specific treatment sequence based on the data provided by the diagnostic tool. Although workstation 104 is shown as a separate workstation 104 for use, for example, in a distributed system shown in PCT / EP97 / 02821, it and / or its functionality could be used in many of the other components of the 39418 shown in FIGS . 7A, 7B and 7C 00070 552 001000280000000200012000285913930700040 0002010014480 00004 39299e system. For example, a laser system 106 is also shown in FIG. 7C, which receives both the treatment sequence generated by the work station computer 104 and corresponding iris data. In the Lasersy stem 106 , the functionality of the workstation 104 could be integrated, so that a suitable laser treatment would be generated within the laser system 106 itself.

Starting with FIG. 7A, the corneal topography system 100 generates topographic data from a patient's eye E. The topography system shown has hardware 108 similar to a placid disk, and a pupil or iris camera 110 . These components are known and various techniques for generating corneal topography data are known. For example, the System 2000 from EyeSys generates corneal topography data, and the topography system ORBSCAN II® from Orbtek not only generates corneal surface topography data, but also total topography data for the various eye components. The former system is a system based on a Placidos disc, the latter system is an automatic slit lamp system. The ORBSCAN II® system uses surface heights and a tracing technique to determine refractive errors in the eye. The topography system 100 may typically generate output data 112 in various formats that are generated using various techniques, e.g. B. in the form of absolute corneal heights at different points, of corneal curvatures at various points, and the like.

In addition to the corneal data 112 , the corneal topography system 100 also creates a corresponding "snapshot" of the visible surface of the eye E, thereby providing first iris (and pupil) image data 114 that represent an iris (and pupil) image 120 . Many corneal surface topography systems have a pupil camera that can produce this image. As will be discussed in more detail below, the pupil or iris camera 110 can provide the iris image data 114 in various formats, e.g. B. as a standard image format, or as a reduced format in which various iris or pupil structures or features are identified. These structures or features can have those that are identifiable along the edge of the interface between the pupil and the iris. Iris image data 114 may be a combination of an image and identified structures or features of the iris, the pill, its interface, or other eye structures.

The pupil or iris camera 110 can be one of various camera types, e.g. B. a camera working with visible light, an infrared camera or another camera that is suitable for taking the iris image 120 . Preferably, the image is generated at the same time that the topography components (the hardware similar to a Placido's disk) 108 generate the topography data 112 , although an earlier or later time would also be acceptable.

As shown in FIG. 7A, the topography data 112 and the iris image data 114 are preferably related to each other according to a coordinate system, as shown by superimposed images 116 . The relationship between a particular topography 118 and iris image 120 is maintained in the data.

As discussed below, the iris image data 114 is suitable for the iris image 120 for aligning or aligning a surgical or surgical tool (here the laser system 106 ). However, data 114 is also useful for normalizing data from various other eye diagnostic instruments or devices. In particular, the wavefront sensor 102 also analyzes refractive irregularities or aberrations in the eye E. In the wavefront sensor 102 , a pupil camera 122 is preferably focused on the eye E in front of a certain “telescope” optics 124 . The telescope optics 124 (e.g., a device for adjusting the focus or the optical path) is used to change the optical path length and to focus a laser 126 on the retina of the eye E. The telescope optics 124 can be used to reduce low order optical aberrations of the eye E, e.g. B. Defocus, determine and compensate. In one embodiment, the wavefront sensor 102 generates data for determining optical aberrations in the eye E via a lens camera 128 . As discussed above, various other wavefront sensors or system types can be used to determine refractive ophthalmic wavefront aberrations.

As with the corneal surface topography system 100 , the wavefront sensor 102 preferably provides aberration data 130 and iris (pupil) image data 132 from the pupil camera 122 . An aberration profile 134 - e.g. B. a wavefront sensor light spot profile from which the centroids of the light spots are determined to determine the wavefront aberrations of the eye, as described by Williams - and obtain an iris (and pupil) image 136 . Iris image data 132 may be similar to iris image data 114 . The wavefront sensor data 130 and the iris image data 132 are also normalized to one another, as represented by an overlapping reference frame 138 in FIG. 7A. The pupil may be dilated when the aberration data 130 and the image data are generated, or may remain in the non-dilated state.

When developing a course of treatment for a refractive surgery, e.g. For example, LASIK treatment, various types of refractive data can be determined and used. This data may be corneal topography data, wavefront sensor data, corneal thickness data or other differential or difference profiles (e.g. determined using ultrasound) of eye components and other such refractive data generated by various methods, e.g. B. by slot scanning or slot scanning or optical coherence topography techniques. For example, ultrasound can be used to measure not only the corneal thickness, but also the epithelial and other eye surfaces, the proportion of the stromal component in a corneal disc obtained by a microkeratome incision (for LASIK), the residual current under the corneal disc, and similar parameters to eat. This data is typically provided on a point-by-point basis for the eye E with different resolutions. For example, the corneal topography data 112 from the corneal topography system 100 will generally have a higher resolution than the wavefront sensor data 130 . Similarly, certain types of data relate to an aspect of eye E, e.g. B. the corneal surface topography data 112 , which map the surface topography of the eye E, while other data may reflect other aspects of the eye E, e.g. B. found in the wavefront sensor data 130 from the wavefront sensor 102 which total refractive errors.

In addition, the refractive diagnostic tools could ver have different configurations, for example assign a fixed system, a table system or a handheld system or several in one integrated systems. For professionals it can be seen that the techniques of the invention in one implement a wide variety of physical embodiments are animal.

According to one embodiment of the invention, these data records are normalized to one another for a more precise generation of a refractive treatment. Here, the topography data 112 and their corresponding iris image data 114 are normalized to the wavefront sensor data 130 and their corresponding iris image data 132 . For example, these two data sets (represented by a diagram 140 ) are normalized to one another based on similarities of the iris image 120 and the iris image 136 (represented by an iris image 142 ). As discussed above, this normalization can be obtained by overlapping or overlaying the iris images themselves, or instead by matching or adjusting characteristic elements of the iris (and pupil) images, as described below in connection with FIG. 8.

In a particular embodiment shown in FIG. 7B, aberration profile 134 is processed (e.g., by Zernike polynomial matching, as discussed by Williams and herein) to develop wavefront aberration data that is referred to as pupil wavefront aberration (e.g., contour ) diagram 160 are shown. The wavefront sensor data 130 and the iris image data 132 ( FIG. 7A) are also normalized to one another, as shown by an overlapping reference frame 162 in FIG. 7B. As discussed above, the pupil is preferably dilated when the aberration data 130 and the image data are generated, and these data sets are normalized to one another for more accurate generation of refractive treatment. The topography data 112 and its corresponding iris data 114 are normalized to the wavefront sensor data 130 and its iris image data 132 . For example, the normalization of this data is represented by a (superimposed) diagram 164 , which is parallel to the above discussion of FIG. 7A based on similarities of the iris image 120 and the iris image 136 (represented by an iris image 142 ). Topography data 118 extends over a larger portion of the eye, e.g. B. over the largest part of the cornea or over the entire cornea, while the wavefront aberration diagram (or the wavefront aberration data) 160 generally extends over the pupil or a part of the pupil. It will be apparent to those skilled in the art that some correlation between the pupil wavefront aberration diagram 160 and the topography 118 , if overlapped like or similar to the diagram 164 , can be seen, even if for the adjustment or the adjustment or for the alignment or normalization no iris image data are used. In order to normalize or superimpose the topography and the wavefront aberration data (e.g. the topography data 118 and the pupil wavefront aberration diagram 160 ), the changes in the optical path length (e.g. from the wavefront aberration data) or the refractive index (e.g. by averaging of refractive indices) of the eye are appropriately taken into account in order to correct this data, as can be seen by experts.

Regardless of whether data is generated in accordance with the method shown in FIG. 7A or in FIG. 7B, a computer program subsequently generates a treatment profile 144 , as shown in FIG. 7C. This can be done, for example, by a stand-alone computer 104 , a computer connected to the Internet or another network, or in a computing system that is part of the laser system 106 , the topography system 100 , the wavefront sensor 102 or other systems. The treatment generated could be one of several treatments. For example, an irregular treatment pattern could be performed, as illustrated in the aforementioned U.S. Patent No. 5891132, or various other types of treatment could be performed, e.g. B. a laser treatment with variable light spot size, with a slot scanning or slot scanning technology or with a fixed scanned light spot size. Regardless of the treatment carried out, the treatment pattern with respect to the data 140 or 164 is generated by various diagnostic tools and can be kept standardized on the stored iris image 142 .

The data from the various diagnostic tools can be used in various ways to generate treatments. For example, only the data 130 from the wavefront sensor 102 could be used to generate a treatment, or instead the data 112 from the corneal surface topography system 100 could be used. Only other alternative types of refractive diagnostic tool data can be used to generate treatments. Advantageous aspects of the data from the different tools could be combined to produce better refractive treatments overall. Be at play as the corneal surface topography system 100 sends surface topography data regardless of the expansion degree of the pupil back, the wavefront sensor 102 may vary but by the degree of expansion of the pupil limited (that is, the wavefront sensor 102 typically only measures refractive effects of optical elements that are located in the optical path). Therefore, as shown by diagram 164 of FIG. 6B, data 112 from corneal surface topography system 100 is used in a surface area that is larger than the dilated pupil, while data 130 from wavefront sensor 102 is used for the central portion within the pupil area . In both cases, the data 130 and the data 112 can be compared by a first spatial standardization using their respective iris images 120 and 136 .

According to Fig. 7C is lung 144 is typically a course of treatment based on the generated treatmen, z. For example, a series of shots, a series of slit scans with different aperture sizes, or various other treatments, are provided for a particular type of laser system 106 . The treatment sequence represented by a profile 146 is spatially related even to the data 148 representing the iris image. The data 148 could in turn be an image of the iris itself, a high-contrast black and white representation of the iris, a positional representation of various features of the iris, or various other representations of the iris. In general, the data 148 representing the iris should be suitable for comparing the course of the treatment 146 with the real iris of the eye E if the eye E is to be treated by the laser system 106 .

Laser system 106 is then loaded with the treatment profile, including treatment process 146 and iris data 148 . According to Fig. 7C, the laser system 106 may be one of various types of laser systems such. A 193 nm excimer laser, and will typically be a laser 150 , a target system 152 (e.g., a series of optical components used to direct light from laser 150 to eye E), a pupil camera 154, and a Control system 156 have. A lower power target or reference beam (not shown) is typically used in conjunction with laser 150 . The target beam, e.g. Laser beam, can be monitored by pupil camera 154 , which is typically an infrared camera, and can be used to align laser 150 , as described in U.S. Patent No. 5,620,436, entitled "Method and Apparatus for Providing Precise Location of Points on the Eye ", he shares on April 15, 1997 [PCT / EP95 / 01287, published on October 19, 1995].

In operation, the control system 156 , which controls the target system 152 , is fed an image of the iris I (see FIG. 7C) of the eye E through the pupil camera 154 . The actual iris I image supplied to the excimer laser system 106 is compared to the iris data 148 associated with the treatment flow 146 . The target of the laser head 150 is then set so that the iris data 148 are substantially aligned or matched with the image of the iris I provided by the pupil camera 154 . This can include translation, rotation, scaling or tilt functions or various other transformation functions. The translation that is applied to the iris image data 148 and is necessary to match it to the iris I is similarly performed in the treatment flow 146 so that the final treatment flow, when applied, corresponds to a treatment flow that is necessary , is to reduce the optical effects predicted when generating treatment profile 144 .

The data of the treatment process 146 itself can be changed, or instead the target of the laser system 106 or the rotational orientation of the patient can be changed. Regardless of the method, iris data 148 is used to align iris I before treatment 146 is applied.

The techniques described can be in different ways gene eye surgery can be used to advantage. A PRK (photorefractive keratectomy) procedure can be applied to the outside area of the eye can be applied, or a LASIK procedure can be done by first part of the cornea incised backwards and then the laser treatment on the underlying part is applied. You can also the techniques themselves may be suitable for others, non-Kera tectomy treatments, e.g. B. Excimer keratomy, or ver different thermal methods for refractive correction door. These treatment procedures can be done with the iris of the eye be matched exactly so that the calculated treatment  Patterns for theoretically optimal positions generated more precisely becomes.

Other advantages result from using the Iris data in connection with the diagnosis and the treatment performance data. For example, if a patient is for a Diagnostic analysis can be in an upright position the eye position compared to a reclined buttocks sition of the patient sometimes within the base of the eye be slightly turned. Similarly, the orientation of the Turn the patient's head if the Body remains in the same position. Although the brain the patient compensates for such a slight twist can in a high-precision corrective treatment the eye for defects of higher order through the revolving house literally change direction regarding treatment the position can be unscrewed, causing the eye to fail is treated in custody. The effects of such misalignment tion are for basic treatment processes, e.g. B. for myopia and Hyperopia and even for minor treatments of Astigmatism is typically not essential for defects higher order, e.g. B. uneven astigmatism, Blen dung, halo, and the like, can take advantage of high-precision However, treatment is lost if there is no precise deviation immediately with the optimal spatial treatment position hold and is maintained. The techniques of the invention can reduce such alignment or alignment losses ren.

Various techniques can be used with respect to iris adjustment and alignment itself, either using real images of the iris or digital representations of various features of the iris. These techniques have been used in recognition systems based on unique features of an iris, such as. See, for example, U.S. Patent No. 5572596 to Wildes et al., Issued November 5, 1996, entitled "Automated, Non-Invasive Iris Recognition System and Method", assigned to David Sarnoff Research Center, Inc., Princeton, New Jersey, and in U.S. Patent No. 4,641,349 to Flom et al., Issued February 3, 1987, entitled "Iris Recognition System", both of which are incorporated herein by reference. The first of these patents describes scaling, rotation and translation; the latter of these patents discuss various features that can be used to uniquely match and identify an iris, and also discuss that a control mechanism can be used to adjust the position of the iris with respect to the camera. In one embodiment of the present invention, a similar technique can additionally be used to align laser system 106 . Similarly, in Daugman U.S. Patent No. 5,291,560, issued March 1, 1994, entitled "Biometric Personal Identification System, Bas sed on Iris Analysis," assigned to Iri Scan, Inc., Mount Laurel, New Jersey incorporated herein by reference, which discusses the "optical fingerprint" provided by the iris. The pattern and feature matching or matching techniques of these patents and other known methods are used for alignment or matching purposes rather than for strict identification purposes.

Alternatively or additionally, the camera 154 of the laser system 106 can record an image of the iris I, which is then displayed on a screen. The iris image data 148 can then be overlaid to allow a doctor, technician, or other medical professional to manually set up or align the laser system 106 or to manually verify the target of the system 106 .

Figure 8 shows the iris I of the eye E in greater detail to illustrate how certain features can be used to adapt the patient's eye E to a treatment using his or her previously stored image of the iris (I). For example, a set of points 200 that have generally circular features, e.g. B. define small collars, used as descriptors, ge just like grooves 202 or radial grooves 204 . Other usable features are generally described in the aforementioned Flom U.S. Patent No. 4641349, which includes pigment spots, pits, atrophic areas, tumors, and congenital filaments or fibers. Similarly, the pupil for iris adjustment, e.g. B. be used as a center reference point, starting from which then iris features define the rotational position of the eye. It can e.g. B. depending on the complexity of the treatment to be applied less or more features are used. If the treatment is rotationally symmetrical, e.g. B. a treatment for pure myopia or hyperopia, a rotational offset has no consequences, so that the center can be localized with respect to the pupil. In a more complex treatment, however, more detailed features can be used for a more precise adjustment of the eye E before the treatment. Alternatively, artificial features for determining the position can be impressed on the eye E, also in the iris area. For example, three laser marks can be created on the eye if the treatment is to be performed before the laser marks would heal. Then the diagnosis steps can be carried out and treatment can follow immediately. In addition to the iris I, other characteristic sections of the visible surface of the eye can be used. In all of these techniques, the features of the visible portion of the eye are used to compare the diagnostic system, the treatment developed, and the actual treatment applied to the eye E.

Fig. 9 shows various settings that can be made based on the signal received by the laser system 106, the real image of the iris I. According to Fig. 7C, the treatment generated 144 is provided as a desired fil Behandlungspro 146 for controlling the laser system 106. The corresponding reference iris image data 148 from the diagnostic tools are used to compare the treatment pattern 146 with the patient's eye E. The iris image 206 is provided by the pupil camera 154 of the laser system 106 and supplied to the control system 156 . The control system 156 compares the image 148 or the descriptors derived from this image with the iris image 206 . Based on the comparison, different scaling functions are applied to the desired treatment 146 . For example, it can be determined based on the total size of the real iris image 206 that the scale of the treatment should be reduced due to different focal lengths of the diagnostic tools 100 or 102 and the laser system 106 . Such scaling 208 is calculated and applied, whereby a scaled treatment 210 is obtained. It can then be determined that the now scaled, desired treatment 210 must undergo both translation and rotation, as represented by a translation and a rotation function 212 . This is applied to the scaled desired treatment 210 , whereby the real treatment 214 is obtained. This data is then used by laser system 106 to carry out the actual treatment.

Alternatively, if the control system 156 has sufficient computing power, each shot (ie laser pulse) can be appropriately rotated and translated or shifted in parallel. This may be desirable if, for example, the eye E has a greater degree of dynamic rotation and movement during the treatment. Then the iris image 206 can be tracked, and the scaling functions 208 and 212 shown in FIG. 9 can be applied dynamically to the individual treatment or each sequence in the desired treatment pattern 146 . In this way, the treatment of the movement of the eye E can be adapted by shooting. This technique can be combined with the laser targeting or alignment technique described in PCT / EP95 / 01287 so that the exact placement of each shot or shot sequence with respect to iris image 206 is determined before the shot or shots are performed.

Therefore, in embodiments of the invention, a a variety of diagnostic tools with one Camera or other image capture device equipped the one that is an image of the pupil, iris, or some other characteristic feature of the exterior of the eye and transmits data corresponding to this image. Then it will be, if refractive treatment, e.g. B. an excimer laser heel act in a LASIK system, the food is carried out saved image (or its characteristic components) compare the real image of the pupil, iris or eye Chen to align the laser so that the treatment according to the calculation is carried out precisely.

Figs. 10 and 11A-11B show an alternative method of using an egg ner in advance generated image iris I for ensuring a suitable balance egg ner laser treatment with the calculated treatment profile. FIG. 11A shows a general provided by the camera 154 of the La sersystems 106 of FIG. 7C display 252nd On the left side, the image data of the iris I are acquired if a refractive diagnostic tool has been used to determine the refractive properties of the eye E. A treatment profile was developed from these data in comparison with this image data 250 of the Iris I. On the right side of the visual display 252 , the real-time image 254 of the iris I is shown, which is sent back by the camera 154 of the laser system 106 . As can be seen, the real-time image 254 is slightly offset in the direction of rotation compared to the captured image data 250 . This enables the physician to realign the patient's eye E so that an appropriately aligned real-time image 256 of the iris I is obtained in FIG. 11B. The visual display preferably has reference axes which enable the doctor to easily determine the rotational offset. The system could also have, for example, a cursor that the doctor would place over identifying features in order to determine the rotational position with respect to the axis exactly.

Figure 10 shows the steps for using the system of Figures 11A and 11B to align the iris. First, the who the captured image data 250 of the Iris I shown in step 260 . At the same time, the real-time image 254 of the Iris I is displayed in step 262 . If the excimer laser system 106 is a Keracor 217 type system in which an eye tracker is used, the doctor then activates the eye tracker in step 264 , centering the real time image 254 . With the Keracor 217 eye tracking system, the iris I is centered, but the iris I cannot be rotated.

In step 266 , an axis is displayed on both the acquired data 250 and the real-time image 254 . The doctor then compares the images on the screen and determines the degree of rotation required to compare the two images of the iris I. The doctor then rotates the eye E so that the real-time image 256 of the iris I corresponds in the direction of rotation to the iris image data 250 it has captured. The doctor can do this manually, e.g. B. using a suction ring, or by positioning the patient's head. In addition, the system can provide a "virtual" rotation of the patient's eye E by rotating the treatment profile by a value determined by the doctor. The real-time image 254 of the iris I is first centered by the eye tracking system, and then the doctor rotates the image 256 of the iris I with respect to the captured image data 250 .

Other alternatives have a system in which the overlay both images. In addition, if meh More diagnostic and refractive tools are used other alignment or matching techniques be applied. For example, a wavefront tool its data based on the iris outline in conjunction with a rotation mark or an astigmatism axis chen. A topography tool could do the same thing Use adjustment or comparison bases, but also an iris image to capture. This could then be aligned or aligned treatment profiles on the laser using finally the iris data are compared. It could different permutations are used that are in the by the proxy of this application at the same time filed patent application entitled "Iris Recogniti on and Tracking for Treatment of Optical Irregularities of the Eye ". In addition, the doctor can use ver support for various user interface tools the, e.g. B. by the aforementioned cursor position tion and the rotation of the treatment profile through the sy stem software.  

The foregoing disclosure and description of the inven are used for presentation and explanation, and within the scope of the present invention can be numerous che changes in the details of the device shown and carried out in the design and operating procedures men.  

Reference list Fig. 1

locally averaged wavefront. , .: Locally averaged wavefront slope (θ)
lenslet array: lens array
lenslet diameter (d): lens diameter (d)
spot displacement (Δ): beam spot displacement (Δ)
wavefront: wavefront
focal length (f): focal length (f)
measurement sensitivity: measurement sensitivity

Fig. 2

surface topography based. , .: Surface topography-based ablation profile
wavefront based. , .: Wavefront-based ablation profile
combined ablation profiles: combined ablation profiles

Fig. 3

460

Ultrasonic

462

Corneal surface topography

464

Combined refractive diagnostic tool

466

Aberrometer

Figure 4A

502

Topography survey is used for screening

504

Good candidate? YES NO

506

Rejection of the candidate

508

Bad eye? YES NO

510

Plan height-based ablation

512

Do ablation

514

Good result? YES NO

516

Good result

518

investigation

520

Suitable for further treatment? YES NO

522

Best possible result

524

Do a wavefront scan

526

Does the wavefront match refraction? YES NO

528

Plane ablation

530

Do ablation

532

Good result? YES NO

Figure 4B

552

Topography survey

554

Suitable candidate? YES NO

556

Rejected candidate

558

Difficult eye? YES NO

560

Plan height-based ablation

562

Do ablation

564

Good result? YES NO

566

Good result

568

Further treatment possible? YES NO

570

Best possible result

572

Wavefront is calculated according to ray tracing

574

Wavefront light spot positions are predetermined

576

Wavefront investigation

578

Measured pupil wavefront is determined

580

Topography-based wavefront is calibrated

582

Measured pupil wavefront and topography-based wavefront are combined

584

Ablation profile is derived from the wavefront

588

Compare with height-based ablation and determine whether post-surgery is required

590

Perform wavefront ablation

Fig. 5

302

Laser diode 660 nm

304

Eye lighting

306

Laser diode 780 nm

308

Beam splitter R = 20%, T = 80%

310

Polarization beam splitter

312

Lens camera

314

prism

316

mirror

318

Beam splitter R = 20%, T = 80%

320

λ / 4 plate

321

Small lens and aperture

322

mirror

323

Adjustment camera

327

cover

328

Pupil camera

332

Beam splitter R = 50%, T = 50%

334

Fixation target

336

lighting
E eye

Fig. 6

10th

Mapping the iris in connection with diagnostic tool (s)

12th

Develop treatment standardized on iris image

14

Same laser target and treatment pattern on iris image

16

Do treatment

Figure 7A

normalize to iris: to 144 (

Fig.

7C); Normalize on IRIS: to 144 (

Fig.

7C)

Figure 7B

normalize to iris: to 144 (

Fig.

7C); Normalize on IRIS: to 144 (

Fig.

7C)

Figure 7C

144

Generate treatment

Fig. 9

148

Image of diagnostic tools

146

Desired treatment

206

Image of laser system

214

Actual treatment

Fig. 10

260

Show captured iris data

262

Display real-time image of the iris

264

Center real-time image

266

Display identical axes on captured data and real-time image

268

Turn your eye until features of the acquired iris data match features of the real-time data

Figure 11A

misalignment: misalignment
Press footswitch. , .: Press footswitch to activate the eye tracking system

Figure 11B

Alignment: alignment
Press footswitch. , .: Press footswitch to activate the eye tracking system

Claims (38)

1. Method for developing a refractive profile of an eye with the following steps:
Determining a corneal topography of the eye;
Determining a wavefront aberration of the eye; and
Development of a refractive treatment process for the eye from the specific corneal topography and the specific wavefront aberration.
2. The method of claim 1, wherein the step of determining the corneal topography further comprises at least one of the following corneal topography techniques:
Using a height-based slit lamp topography system to determine the topography of one or more refractive surfaces within the eye; or
Use a corneal surface curvature-based topography system to determine the topography of one or more refractive surfaces of the eye.
3. The method of claim 1, wherein the step of developing a refractive treatment flow further comprises the steps of:
Developing a refractive treatment process based on corneal topography;
Developing a refractive treatment process based on the detected wavefront aberration; and
Combining the developed refractive treatment process for the detected wavefront aberration within a pupil area with that on the corneal topography outside the pupil area is based on the developed refractive treatment process.
4. The method of claim 3, wherein developing a Treatment process the development of a photorefractic ven keratectomy procedure.
5. The method of claim 3, wherein developing a Treatment process the development of a laser in situ Keratomileusis treatment sequence.
6. The method of claim 1, wherein the step of developing a refractive treatment process further comprises the steps of:
Developing a refractive profile based on the corneal topography;
Developing a refractive profile based on the detected wavefront aberrations;
Combining the corneal topography-based profile with the detected wavefront-based profile; and
Development of the refractive treatment process from the combined refractive profile.
7. The method of claim 1, wherein determining the Corneal topography using an ultrasound machine has material for determining the corneal topography.
8. The method of claim 1, wherein determining the Corneal topography determining a surface topo graph of the stroma of the cornea.
9. The method of claim 1, wherein determining the Corneal surface topography determining an upper Surface topography of the corneal epithelium determined becomes.  
10. The method of claim 1, wherein determining the Corneal topography and the detected wavefront the acquisition of an image of the iris Eye, and wherein developing the refractory ven profile the matching of the particular wavefront tabulation data and the determined corneal topogra has data based on the iris image.
11. The method of claim 10, wherein detecting the Iris image the acquisition of an iris image accordingly the particular topography and the wavefront aberration NEN.
12. The method of claim 1, wherein the step of developing a refractive treatment process further comprises the steps of:
Assessing the suitability of the eye for treatment based on corneal topography; and
Development of the refractive treatment process based on the detected wavefront aberration.
13. The method of claim 1, wherein the step of developing a refractive treatment flow further comprises:
Assessing the suitability of the eye for treatment based on corneal topography; and
Use only the corneal topography to develop a treatment process for the eye if the eye is unsuitable for evaluating the wavefront aberrations.
14. The method of claim 1, further comprising the step of Determining a calculated wavefront aberration of the Eye based on the determined corneal topography of the eye.
15. The method of claim 14, further comprising the step of Align the calculated wavefront aberration of the Eye based on the determined wavefront aberration of the eye.
16. The method of claim 14, further comprising comparing the calculated wavefront aberration of the eye with the certain wavefront aberration of the eye in order to vali whether it is appropriate to continue the course of treatment clog.
17. The method of claim 1, further comprising the step of Represent a simulation of the refractive treatment development of the eye on the determined corneal topo graph of the eye.
18. The method of claim 1, further comprising the steps of:
Performing a refractive treatment process for the eye;
Evaluating the effectiveness of the refractive treatment process for the eye; and
Repeat the steps to determine the corneal topography and determine the wavefront aberration to provide a subsequent course of treatment to the eye.
19. System for determining refractive aberrations of an eye with:
a corneal topography tool suitable for providing corneal topography data of the eye;
a wavefront aberration tool suitable for providing wavefront aberration data of the eye; and
a computing unit that is suitable for combining the wavefront aberration data with the corneal topography data.
20. The system of claim 19, wherein the computing unit to is suitable, the corneal topography data and the wel to receive lenfront aberration data and the cornea topography data outside of a pupil area with the wavefront aberrations within the pupilbe to combine empire.
21. The system of claim 19, further comprising a camera that is suitable for obtaining an image of an iris of the eye grasp that to align the wavefront aberrations data is used with the corneal topography data.
22. The system of claim 21, wherein the iris image represents the waves front aberration data and corneal topography data corresponds.
23. The system of claim 19, further comprising: a laser system that is suitable for a Treatment process for the eye based on the combi generated data.
24. The system of claim 23, wherein the laser system with the Computing unit is connected.  
25. The system of claim 19, wherein the computing unit to is suitable for the wavefront aberration of the eye to calculate the corneal topography data.
26. The system of claim 25, wherein the computing unit to is suitable, the wavefront aberration data with the compare calculated wavefront aberration data, to validate both.
27. The system of claim 25, wherein the computing unit is suitable, the calculated wavefront aberration based on the wavefront aberrations tool-provided wavefront aberration data adjust.
28. The system of claim 25, wherein the computing unit is suitable for a refractive treatment process to calculate.
29. The system of claim 28, wherein the computing unit is suitable, a simulation of the based on the Corneal topography data performed refractive Be present the course of action.
30. The system of claim 19, wherein the computing unit between between the corneal topography tool and the waves front aberration tool is distributed.
31. A method for developing a refractive treatment process for an eye, the method comprising the steps of:
Determining a corneal topography of the eye;
Determining a wavefront aberration of the eye;
Developing a refractive treatment process based on the determined wavefront aberration data; and
Develop a refractive treatment process based on the determined corneal topography data.
32. System for determining refractive aberrations of an eye with:
a corneal topography tool suitable for generating corneal topography data of the eye;
a wavefront aberration tool suitable for providing wavefront aberration data of the eye; and
a computing unit which is suitable for receiving the corneal topography data and the wavefront aberration data and for developing a refractive treatment process based on one of the data sets and modifying the refractive treatment process based on the other of the data sets.
33. The system of claim 32, further comprising: a Lasersy coupled to the computing unit stem, wherein the laser system is suitable for the mo differentiated treatment procedure for a laser operation of the eye.
34. The system of claim 33, wherein the laser system with the Computing unit is coupled.
35. The system of claim 34, wherein the laser system is physical is arranged away from the computing unit.  
36. The system of claim 34, wherein the laser system the Re Chen unit.
37. System for developing a refractive treatment process for one eye with:
a corneal topography tool suitable for providing corneal topography data of the eye;
a wavefront aberration tool suitable for providing wavefront aberration data of the eye; and
a computing unit which is suitable for evaluating one of the data sets for the suitability of the patient and for using the other data set for developing a treatment profile.
38. The system of claim 37, wherein the computing unit Executes evaluation based on the topography data and the treatment profile based on the waves front data prepared.
DE2000114480 2000-03-23 2000-03-23 Eye refractive profile developing method for ophthalmic refractive surgery, involves developing refractive course of treatment of eye from determined corneal topography and wavefront aberration Withdrawn DE10014480A1 (en)

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DE2000114480 DE10014480A1 (en) 2000-03-23 2000-03-23 Eye refractive profile developing method for ophthalmic refractive surgery, involves developing refractive course of treatment of eye from determined corneal topography and wavefront aberration

Applications Claiming Priority (18)

Application Number Priority Date Filing Date Title
DE2000114480 DE10014480A1 (en) 2000-03-23 2000-03-23 Eye refractive profile developing method for ophthalmic refractive surgery, involves developing refractive course of treatment of eye from determined corneal topography and wavefront aberration
PCT/EP2000/010375 WO2001028410A1 (en) 1999-10-21 2000-10-20 Customized corneal profiling
CNB008146519A CN1309340C (en) 1999-10-21 2000-10-20 Customized corneal profiling
JP2001531012A JP2003511183A (en) 1999-10-21 2000-10-20 Personalized corneal profile
EP09161366A EP2092876B1 (en) 1999-10-21 2000-10-20 Customized Corneal Profiling
BRPI0015065-7A BR0015065B1 (en) 1999-10-21 2000-10-20 System for determining refractive aberrations of an eye.
CN2006101667944A CN101023860B (en) 1999-10-21 2000-10-20 Customized corneal profiling
ES09161366T ES2390397T3 (en) 1999-10-21 2000-10-20 Custom corneal profile
CA2385909A CA2385909C (en) 1999-10-21 2000-10-20 Customized corneal profiling
ES00971395T ES2326788T3 (en) 1999-10-21 2000-10-20 Personalized corneal profile training system.
AU10264/01A AU778490B2 (en) 1999-10-21 2000-10-20 Customized corneal profiling
DE60042339A DE60042339D1 (en) 1999-10-21 2000-10-20 System for the patient-specific profiling of the horn skin
US10/110,922 US7237898B1 (en) 1999-10-21 2000-10-20 Customized corneal profiling
EP00971395A EP1221890B1 (en) 1999-10-21 2000-10-20 System for customized corneal profiling
SG200403323-9A SG130030A1 (en) 1999-10-21 2000-10-20 Customized corneal profiling
KR1020027005104A KR100797857B1 (en) 1999-10-21 2000-10-20 Customized corneal profiling
HK03102902A HK1050620A1 (en) 1999-10-21 2003-04-23 Customized corneal profiling
HK07114365.1A HK1110759A1 (en) 1999-10-21 2007-12-31 Customized corneal profiling

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003055380A2 (en) * 2001-12-21 2003-07-10 Bausch & Lomb Incorporated Aberrometer illumination apparatus and method
DE102007017611A1 (en) * 2007-04-12 2008-10-16 SCHRÜNDER, Stephan Method and system for eye measurement
WO2010075964A1 (en) * 2008-12-17 2010-07-08 Carl Zeiss Meditec Ag Device and method for determining the surface shape of the cornea of an eye by analyzing the mirror images of spatially distributed patterns
DE102004033819B4 (en) * 2004-07-13 2011-04-28 Iroc Ag Method for generating control data of a laser system for ophthalmological procedures

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003055380A2 (en) * 2001-12-21 2003-07-10 Bausch & Lomb Incorporated Aberrometer illumination apparatus and method
WO2003055380A3 (en) * 2001-12-21 2003-12-11 Bausch & Lomb Aberrometer illumination apparatus and method
US6736509B2 (en) 2001-12-21 2004-05-18 Bausch And Lomb, Inc. Aberrometer illumination apparatus and method
DE102004033819B4 (en) * 2004-07-13 2011-04-28 Iroc Ag Method for generating control data of a laser system for ophthalmological procedures
DE102004033819B8 (en) * 2004-07-13 2011-11-10 Wavelight Gmbh Method for generating control data of a laser system for ophthalmological procedures
DE102007017611A1 (en) * 2007-04-12 2008-10-16 SCHRÜNDER, Stephan Method and system for eye measurement
WO2008125665A1 (en) 2007-04-12 2008-10-23 Schruender Stephan Eye measurement method and system
WO2010075964A1 (en) * 2008-12-17 2010-07-08 Carl Zeiss Meditec Ag Device and method for determining the surface shape of the cornea of an eye by analyzing the mirror images of spatially distributed patterns

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