WO1987000748A1 - Device for ophthalmologic surgery by photoablation - Google Patents

Device for ophthalmologic surgery by photoablation Download PDF

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Publication number
WO1987000748A1
WO1987000748A1 PCT/FR1986/000268 FR8600268W WO8700748A1 WO 1987000748 A1 WO1987000748 A1 WO 1987000748A1 FR 8600268 W FR8600268 W FR 8600268W WO 8700748 A1 WO8700748 A1 WO 8700748A1
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WO
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Prior art keywords
beam
laser
wavelength
characterized
nanometers
Prior art date
Application number
PCT/FR1986/000268
Other languages
French (fr)
Inventor
Danièle Sylvie ARON-ROSA
Original Assignee
Daniele Sylvie Aron Rosa
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to FR85/11671 priority Critical
Priority to FR8511671A priority patent/FR2585558A1/en
Priority to FR85/18171 priority
Priority to FR8518171A priority patent/FR2591097A2/en
Application filed by Daniele Sylvie Aron Rosa filed Critical Daniele Sylvie Aron Rosa
Publication of WO1987000748A1 publication Critical patent/WO1987000748A1/en

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Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F9/00Methods or devices for treatment of the eyes; Devices for putting-in contact lenses; Devices to correct squinting; Apparatus to guide the blind; Protective devices for the eyes, carried on the body or in the hand
    • A61F9/007Methods or devices for eye surgery
    • A61F9/008Methods or devices for eye surgery using laser
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F9/00Methods or devices for treatment of the eyes; Devices for putting-in contact lenses; Devices to correct squinting; Apparatus to guide the blind; Protective devices for the eyes, carried on the body or in the hand
    • A61F9/007Methods or devices for eye surgery
    • A61F9/008Methods or devices for eye surgery using laser
    • A61F9/00802Methods or devices for eye surgery using laser for photoablation
    • A61F9/00804Refractive treatments
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F9/00Methods or devices for treatment of the eyes; Devices for putting-in contact lenses; Devices to correct squinting; Apparatus to guide the blind; Protective devices for the eyes, carried on the body or in the hand
    • A61F9/007Methods or devices for eye surgery
    • A61F9/008Methods or devices for eye surgery using laser
    • A61F2009/00853Laser thermal keratoplasty or radial keratotomy
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F9/00Methods or devices for treatment of the eyes; Devices for putting-in contact lenses; Devices to correct squinting; Apparatus to guide the blind; Protective devices for the eyes, carried on the body or in the hand
    • A61F9/007Methods or devices for eye surgery
    • A61F9/008Methods or devices for eye surgery using laser
    • A61F2009/00861Methods or devices for eye surgery using laser adapted for treatment at a particular location
    • A61F2009/00872Cornea
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F9/00Methods or devices for treatment of the eyes; Devices for putting-in contact lenses; Devices to correct squinting; Apparatus to guide the blind; Protective devices for the eyes, carried on the body or in the hand
    • A61F9/007Methods or devices for eye surgery
    • A61F9/008Methods or devices for eye surgery using laser
    • A61F9/00825Methods or devices for eye surgery using laser for photodisruption

Abstract

Device intended for corneal surgery by photoablation comprising a laser source. According to the present invention, the laser being a solid laser (1), a multiplication of frequencies is effected by means of a crystal (27) in order to obtain an output wavelength of between 150 and 220 nanometers with a space-time distribution of the beam of which the energy is comprised between 100 and 1000 millijoules per cm2.

Description

DEVICE FOR SURGERY OPHTHALMOLOGY photoablation

The present invention relates to an ophthalmic surgical device by photoablation, photodiεruption linear or ultraviolet photodissociation living tissues directly accessible by means of ultra-short pulses whose duration is 10 to 100 nanoseconds, derived from a laser light source coherent and designed primarily, but not exclusively, surgery of the cornea and vitreous.

More specifically, it relates to a device emitting at the output, according to a spatial mode or temporal radiation whose wavelength is in the ultraviolet and in particular in the range of 150-215 nanometers. In fact, the emitted radiation must be outside the absorption band of the human proteins and DNA deoxyribonucleic acid. For these reasons, the range of 230 to 260 nanometers is to be prohibited. Indeed, it was observed that a KRF laser of 247 nm wavelength. correspond to a frequency of DNA and could have carcinogenic effect by breaking of molecular chains. In the low UV spectrum, below 150 nm. radiation is totally absorbed by the air and the addition of a vacuum conveying duct radiation prevent a permanent control necessary for precision surgery.

STATE OF THE ART

Lasers are known for twenty five years and are now used in various fields of microsurgery.

Been described in EP-A-0,007,256 an ophthalmic surgical device including a YAG laser (double yttrium-aluminum garnet emitting pulses of a duration of the order of a few picoseconds with a length wavelength of 1064 nanometers for performing a icrochirurgie intraocular closed globe. the ultra-fast transmission of a small quantity of emergent energy, and the high concentration of light on a microsurface are at the origin of optical breakdown and forming a plasma followed responsible shockwave development of the disruption of the targeted tissue, whatever its chemical nature and independently of any coloring or pigmentation. These lasers are currently used in surgery secondary cataract, including after implantation of an artificial lens, in the treatment of glaucoma and for cutting within the eye all superficial tissues and in particular the re vitreous flanges sponsables some retinal detachments. The high penetration of the radiation YAG and the intensity of the wave generated prohibit direct surgery on the cornea. Furthermore, eight years of experience with a pulsed YAG laser, conducted by the Applicant have shown its limited effectiveness in vitreous surgery.

Was also used argon laser light of continuous wave radiation emitting from 488 to 514.5 'nanometers in order to achieve photocoagulation and laser wavelength of 647 nm krypton equal to the choroid in photocoaguler through the retina itself.

But these techniques require the presence of a medium consisting of the eye itself and can not be implemented in the case of corneal surgery and, until now, no laser was used to sever the cornea without the clot. This type of indication should call a strongly absorbed by the cornea and laser radiation does not penetrate inside the eye.

It is known that the cornea is composed by weight of approximately 80% water and 20% protein. The problem of photo-ablation is to achieve pure water Photodissociation without altering proteins. It has already been used to realize a photodissociation, a laser emitting in the blue, pre 'presence of a metal catalyst with an energy of about 1.8 electron volt photon. But catalysis causes an action on protein, which is absolutely prohibited. On the other hand, the introduction of a catalyst or in the retina may cause problems, oxygen resulting from the dissociation of water recomposed with another constituent of the retina. With energies above (4 to 8 electron / photon), only water is photodissociée and there is no danger of side effects on protein for energy sources indicated above. Moreover, the fact of drawing the laser between 10 and 100 nanoseconds, that is to say well below the thermal relaxation time threshold of water in the stratum, avoids the danger of scattering of thermal effects, and due to extensive tissue burns. The above data have been experimentally observed in a closed vessel under nitrogen atmosphere and in the presence of reactants.

Moreover, recent developments have been conducted on corneal surgery. Professor José BARAKER conducted convexity of corneal changes by cutting it, grinding ication and implementation of the cut portion as a graft. Professor Fyodorov laid down the principles of radial keratotomy. In this operation, a series of 4 to 32 radial incisions is performed on the cornea in order to reshape it. It was thus possible to correct from -1 to -8 diopters myopia. By performing linear incisions perpendicular to the axis of astigmatism, it was possible to correct some astigmatisms. Radial keratotomy is to maintain a definite effect, be extended until the DESMET membrane without reaching it, let alone 1'endothélium not renewable. Currently, the incisions are made diamond knife. The results of this operation are greatly random to the extent that, after some incisions, the cornea is deformed (corneal depression) so that, even with a knife provided with a guard, - ^ incision depth can hardly be constant.

US-A-4,461,294 (BARON) discloses an apparatus and method for achieving radial keratotomy by means of a plotter device including a dye on the cornea (riboflavin). After drawing the pattern of cut lines, evaporated lines marked by means of an argon laser through a slit mask, the lines' being designed by a computer based on the convergence of modification to be obtained. The dye has been introduced into the layer of BOWMAN and in the stroma absorbs the light energy emitted by the laser, which causes the cutting of the labeled tissues. This solution is not satisfactory clinically insofar as it uses a thermal method still difficult to control and where it is not specified if the laser emits continuously or not, the pulse rate and the length of wave being the two elements capital. Only a ultraviolet laser or C02 (12,000 nm) completely absorbed by water for the latter were possible for the cornea.

A first object of the present invention is a device for performing a photoablation of the cornea according to a defined configuration of incisions, carried out simultaneously or quasi-simultaneously, using a pulsed laser, without substantial tissue necrosis ( epithelium, membrane B0 MANN, stroma) to an accurately determined depth, avoiding problems due to corneal depression and providing predictable and repeatable results.

A second object of the present invention is a device providing an output laser beam whose radiation is totally absorbed by the cornea and may not in any case spread in other tissues: lens, retina, choroid or vitreous humor. A third object of the present invention is a device for general purposes différentes- for performing ophthalmological surgeries with a single device.

According to the present invention, the linear photoablation of living tissues device comprising at least one laser source is characterized in that it comprises means for concentrating and focusing the beam emitted by the laser source and the beam spatiotemporal distribution means Release whose wavelength is between 150 and 220 nanometers and the energy between 100 and 1,000 millijoules per cm 2.

It is thus possible, with a device according to the invention not only to perform radial keratotomy securely but also to perform a set of operations each require a different setup in advance, the device having opportunities 'various adaptation for performing all ophthalmic surgical operations. For example, the device may be from a single source: YAG laser operating in photodisruptor triggered mode (Q-switched) or thermal operating in "free running", an argon laser photocoagulator, an argon laser pulse including for the treatment of glaucoma or ultraviolet laser short for corneal surgery or vitreous.

For this you can:

1. By using one or more stages of frequency doublers or a Raman cell, obtain an output laser beam suitable by its wavelength for corneal operations. However, the processing operations that are subjected to the original beam all have poor yields, resulting in part by a strong heat dissipation, and secondly, by the need to origin of a very high power laser, that is to say, to use an additional YAG rod as a power amplifier in the case of a YAG rod to 1'origine.

According to a feature of the present invention, the original laser rod is a rectangular bar of YAG SLAB kind.

Such a laser ensures propagation of the photons resulting from the stimulated emission by multiple reflections within the cavity. This prevents one hand the thermal effects and, on the other hand, produced a little dilated beam. Thus, at comparable power, the yield obtained with a SLAB bar is about 10 times greater than that obtained with an ordinary YAG rod. This beam is single phase with a cleaner phase front which gives, if one doubles the frequency using a crystal of KDP (double phosphate potassium and deuterium) or, preferably, with a crystal of phosphate triple known in the art as KTP, a green laser beam, very clean, the frequency can be doubled again to get better performance with a clean ultraviolet radiation to perform the laser ablation. Thus, it is no longer necessary to use a second YAG rod serving as an amplifier to the first mounting which allowed to obtain the output of the second beam energy of the order of five joules.

2. One can simply use a crystal of sodium borate as converter. It provides easily the 5th harmonic YAG, economically without losing energy or repetition rate without having to go through a Raman cell. In this case a simple removable housing placed before the YAG provides a wavelength of 200 or 210 nm. Obviously, this device permits only photodisruptor YAG wavelength and ultraviolet pulsed C and can not simulate the copper argon, but the device is miniaturized, handy and economical.

When using in place of the YAG rod a ruby ​​laser source, it is possible, by a simple frequency doubling, obtaining a wavelength of radiation at 231 nanometers with very high power, but very low rates .

According to another feature of the present invention, the device uses at least a phase conjugation mirror for cleaning the beam without changing thereof wavelength.

Other features and advantages of the present invention will become apparent during the following description of a particular embodiment, given solely by way of example in the drawings which show:

- The fig.l, an implementation device of the invention in a first embodiment using a YAG laser; _ Fig.2 is a diagram showing the implementation of device 1 to the invention with at least a YAG laser;

- Fig 3, a circuit diagram using at least a ruby ​​laser;

- Fig.4, a fourth assembly including a phosphate laser;

- Fig.5, examples of incisions being formed in the cornea Te using one of the arrangements above;

- Fig.6, an arrangement in which a conjugate mirror is disposed at the output of the laser of origin; _ In Fig.7, a second arrangement in which a conjugate mirror is disposed at the output of the beam-splitting stage. Sources laser currently on the market, known lasers "excimer" (excited dimer) fluorite argon (ARF) emitting at 193 nanometers. The excimer laser beam delivers pulses of 10 to 30 nanoseconds Within 6 electron volts / photon. In the assembly shown in fig.l, the apparatus comprises a laser source 1, fluorine excimer argon, enclosed in a housing 8 resting on the ground by a support (not shown) or mounted on an optical bench. At the one laser outlet is mounted a plug 2 electrically controlled whose "curtain" is formed by a glass slide "Schott KG3", for example, controlled by a trigger pedal 14 or by a voice-activated computer. After passing through the shutter, the laser beam 10 is directed to the input of an articulated arm 7 provided with a reflective mirror assembly 9 adapted to the wavelength of the excimer. Of course, within the casing 8 are mounted cooling devices (not shown) allowing the laser and the various components of the system to work at a suitable temperature. According to the invention, the beam 10 is not focused when transferred on the operating head. It manages, at the exit of the arm 7 of a converging device 13, included in the operating microscope 3 (or in a slit lamp) which focuses the beam 10 at a point 12. The device also comprises within the housing 8 a Pockels cell (not shown) for ensuring the locking of modes. According to one characteristic of the invention, the lenses constituting the convergence system 13 are fluoride lens Calcium (CaF2) or "Spectrosil B" bodies which are transparent to the 193 nm wavelength emitted by the laser 1. beam 10 then has the form of a line of ten to two hundred microns wide by three to four millimeters long. A transducer or deflector beam 4 disposed in the vicinity of the line 12 is constituted either by an acousto-optical modulator Brague fringes in the case of time division of the beam, or by a set of cases mirrors for spatial distribution of the beam . In the case of an electro-acoustic modulator, which deflect the beam in both horizontal and vertical planes respectively, the control is obtained by a program 5 microprocessor depending on the configuration of the corneal incision that is desired. Inside the casing 8 there is also an alignment laser 6, for example of the type with helium-neon with a power of 1 milli att, for example to operate with accuracy and properly dispose the incisions on the cornea, since, obviously, the UV beam is not visible. The laser 6 emits through an afocal optical continuous beam 11 which is superimposed on the beam 10 of the laser 1. The excimer laser 1 delivers pulses of 10 to 30 nanoseconds. From an adjustable slot on top of 4mm 0.1 to 0.2 mm wide or less (e.g. 10 to 200 microns), each line of incision is scanned in 30 nanoseconds. 01 The eye surgeon observes the eye 02 of the patient through the microscope 3, preferably through a protective plate (not referenced). With the excimer laser, the cell 27 does not exist.

The excimer laser used to perform an photoablation by photodissociation of the material without, at the periphery of the area sprayed, deterioration too marked by thermal effect. The incident energy diffuses little and is mainly used to locally photocouper matter. Unfortunately, the beam of these lasers is not clean, that is to say, it is a highly random geometry, it is not pure, it is multimode, and difficult to focus. In addition, gas lasers are difficult to manufacture in series, and pose security problems in case of leaks, especially when the gas used is such an active compound as fluorine, although precautions are taken by the automatic regeneration gas and stabilization measures avoiding frequent refills despite repeated work.

Also, according to another characteristic of the invention, the laser source is preferably a solid state laser. But there is no solid lasers emitting in a suitable wavelength and with suitable power for corneal surgery.

1 the laser source may then be a YAG source, advantageously SLAB type mounting scheme is that shown in Figure 1 and corresponds to that described in EP-A-0007256, with the exception of scan final spatiotemporal. Of course, the nature of the mirrors is matched to the YAG radiation wavelength.

The only difference in the assembly consists in the interposition before or after scanning a cell 27 sodium borate which converts the wavelength of the 1064 nm beam at 200-210 nm, that is, say a practically ideal wavelength for surgery of the cornea.

According to the invention, the desired results have also been obtained as described below.

Figs 2-4 show mounting methods for obtaining laser radiation for the wavelength range defined previously (150-215 nm) from a bar laser source. In these diagrams, have been figured as the main elements and plugs, cooling devices and the Pockels cell providing active Qs itching have been omitted. Fig.2 shows a second arrangement in which the original beam is emitted by a YAG laser whose wavelength (1064 nm) is much greater than the wavelength of the ultraviolet laser used in the first embodiment .

The device comprises, in this case, a first laser YAG 1 (double aluminum garnet and yttrium neodymium-doped) followed by a second YAG laser 21, amplifier mounted in series with the first. Is thus obtained at the output of laser 10, an energy of 5 Joules about. The YAG laser beam is pulsed at a frequency such that the pulse duration is between 10 and 100 nanoseconds. Of course, the power required at the output must always be comprised between 0.1 and 1 Joule to the desired biophysical result. But it will be necessary to increase the original frequency to fall within the absorption range of the cornea. For this purpose, the device comprises: an electrically controlled shutter consists of a Schott KG3 glass plate, an optical system said afocal for adjusting the convergence of the alignment beam and the main beam so that the two beams coincide in the operating area and a Pockels cell providing the active Q-switching.

Behind this set is disposed a first cell 22 of KDP or KTP (double or triple phosphate and potassium deuterium) for performing a tripling of the frequency by selecting the third harmonic so that the output of the cell 22, the length beam emerging wave is 266 nanometers. Of course, this result can be obtained, as shown in Fig.2, by arranging in series two frequency doublers which the first 22 selects the first harmonic and the second 23 selects the third harmonic. It is known that by adjusting parameters such as the orientation of crystal, the polarization of the incident wave and the temperature was now obtained with such cells, yields up to 80% but decreasing very rapidly with the rank of the harmonic. The remainder of the light beam 10 (1064 nm) is mixed by the link 25 with the third harmonic in a RAMAN vessel 24 whose output supplies a wavelength of radiation at 217 nm and a maximum power of 800 mJ / cm2.

As in the previous example, the device is mounted on a surgical microscope through an articulated arm and contains a beam deflector similar to that described in the previous embodiment for the excimer laser fluoride 'argon. It is thus possible to obtain a device producing ultraviolet laser radiation from one or two YAG lasers, the purpose of this device is to avoid a heavy maintenance, reduce the cost of mounting and avoid insecurity due to possible leaks fluorine and instabilities inherent in excimer laser. It is thus possible in a short ultraviolet laser beam better than 1'excimer.

The device shown in Fig.3 uses a single ruby ​​laser 1 nanosecond pulsed whose wavelength is 694 nanometers. It is known that in lasers such as the active medium consists of a crystal of alumina (A1203) doped with 0.05% of chromium ions. Such a laser provides a gain equal to two to four times the pitch of a YAG laser, which avoids the use of a laser amplifier. But this wavelength is too large to be used as such in corneal surgery. As previously, we proceed to a first frequency doubling at 22, then to a second dubbing 23. Preferably, the crystals of KDP are replaced by ADP crystals (phosphate double ammonium and deuterium) or KTP . Thus, a first harmonic of wavelength equal to 347 nm, which can not be used because too penetrating and a second harmonic whose wavelength is 175.5 nm. whose wavelength falls within the useful radiation range for surgery of the cornea.

If an amplifier is needed, a similar arrangement to the previous is achieved with two ruby ​​lasers 1

21, one of which serves as a power amplifier to the laser transmitter.

In Fig.3 the ruby ​​laser 1 has an output of about 20 Joules at the output and is followed by two doublers

22, 23 of ADP. As before, the output beam from the splitter 22 is directed onto a slit followed by an electro beam deflector or even purely optical. Indeed, the power at the output of the second splitter selecting the third harmonic can vary from 5 to about 10 Joules. By a set of four or eight mirrors, it is possible to see the image of the slit on the cornea, according to a suitable configuration. All cutting patterns on the cornea are thus made possible. In addition, the cost of the device is very low.

Fourth means uses a phosphate laser source emitting radiation whose wavelength is 1054 nm. In the same manner as above, is treated original beam to separate the third harmonic, on slides 22, 23 in ADP, KDP or KTP, the wavelengths being: first harmonic 527 nm; Second harmonic and third harmonic 263.5 nm 131.7 nm. The wavelength of the third harmonic is too low for it to be used directly (air absorption). Also, the output of the third splitter, there is a RAMAN vessel 24 on which the third harmonic is simultaneously applied and a deviated portion 25 of the original beam, so as to cause a beat frequency. The first frequency radiated antistoke a cone centered on the main beam was fixed at 193 nm. is the excimer laser wavelength argon fluoride.

The blades ADP or KDP crystal or sodium borate are mounted articulated on a support so as to be removable and out of the beam path. Thus, from one of the devices described above, it is possible to carry out a plurality of eye surgery using laser beams of different wavelengths. With the mounting of Fig.2, one can either open a posterior capsule by inhibiting the action of the blades 22 and 23 of KDP or 27 sodium borate or proceed to corneal incisions.

Fig. 5a shows a first example of radial incision of the cornea C obtained by the method according to the invention. T cut lines are arranged radially so as to enable rectification of the convexity of the cornea. On Fig.δb is shown a second mode of incision by photoablation, T incision lines being arranged at an octagon, it was found that this arrangement virtually eliminated postoperative astig atismes in keratoplasty. These configurations, as well as any other desirable configurations are obtained by a deflection of the beam 10 which is divided into a plurality of secondary beams or through an acousto-optical transducer or through a mirror set.

In Figure 6, there are a solid laser source 1 which emits a directed beam towards a first stage doubler 22 of KTP. The beam used in the output stage 22 has a frequency double that of the frequency emitted by the laser 1 and transmits a result substantially in the green. Part of the energy of the output beam of the order of l / 100th for example, is imposed by the optical path 25 and then applied to the stage 24 at the output thereof. The levy is intended to constitute the aiming beam. The cell 22 is followed by a second cell 23 advantageously consists of a KTP crystal. The beam, after passing through the cell lining 23 is then conveyed on the stage 24 for performing a distribution or spatial or temporal beam.

In Figure 6, the mirror 26 is disposed directly at the output of the laser cavity 1, and it is thus purified beam which is directed onto the lining cells 22 and 23.

However, the conjugate mirror 26 may be disposed anywhere on the beam path and, for example, as in Figure 7, the output of the stage 23 or 24 on the beam distribution stage, before division of thereof or to the input of the stage 24.

The diagrams of Figures 6 and 7 show an assembly with a solid state laser (e.g. ruby) emitting radiation of wavelength equal to 694 nanometers, including the quadrupling of frequency for a cell of KTP (22) gives a second harmonic wavelength of 173.5 nanometers. In the case of a YAG SLAB laser emitting radiation of 1064 nm, there is provided a mixing of the third harmonic with a portion of the beam taken at the output of the laser 1 in a vessel RAMAN.

Of course, in the corneal surgery apparatus is mounted on an ultrasonic pachymeter for measuring corneal thickness. A computer is used to find the depth of the incision and a locking device immediately stops the operation of the laser source in the event of movement of the eye than four microns. The depth of incision is currently of the order of 1 micron per shot of the laser being pulsed at a rate of 2 to 100 Hertz. The depth of tissue to be cut is, according to the operations, at most equal to about 600 microns.

When the operation is long, it is possible to immobilize the eye by means of a plastic contact lens UV opaque, having slots distributed according to the desired configuration for the operation.

Claims

1. Apparatus for ophthalmological surgery, including corneal keratotomy, comprising a laser source emitting an original beam and means for focusing and mode locking, characterized in that it further comprises means (4, 5) division of the output beam and spatio-temporal distribution of the divided sub-beams, the wavelength of the output beam being. between 150 and 220 nanometers, the beam energy being between 100 and 1000 millijoules per cm2.
2. Device according to revendication.1, characterized in that the laser source (l) is constituted by an excimer laser argon fluoride emitting radiation of 193 nm, pulsed at a rate of 5 to 30 nanoseconds, a system of calcium fluoride lens (12) or "Spectrosil B" focusing the beam into a line of 10 to 200 microns in width, a height of 3 to 4mm, the stripe being applied to an acousto-optic modulator (4) controlled by a microprocessor (5), deflecting the output beam according to the desired configuration.
3. Device according to claim 1, characterized in that the laser source (1) is a solid rod laser emitting radiation of wavelength 1064 to 500 nanometers, the frequency of the emitted wavelength is divided by a factor determined by means of at least one crystal cell KDP, KTP or ADP (22,23) or a crystal of sodium borate (27).
Device according to claim 3, characterized in that beating is carried out between the selected harmonic and a portion of the original beam in a RAMAN tank (24).
5. Device according to claim 3, characterized in that the laser source (1) is a YAG doped with neodymium, SLAB type, emitting a wavelength of radiation at 1064 nm, the output beam being applied to a sodium borate converter (27) for obtaining the fifth harmonic.
6. Device according to claim 3, characterized in that the laser source (1) is a neodymium-doped YAG -Laser emitting wavelength of radiation equal to 1064 nanometers, connected in series with a second YAG laser (21) amplifier, the output of the laser beam (21) being applied to a first doubler stage consisting of a doubling crystal (22) of KDP, KTP or ADP, and then on a second frequency doubler stage (23) delivering a radiation length wavelength equal to 266 nanometers, said radiation being mixed with a portion (25) derived from the original beam into a vat of RAMAN (24), so that the output beam has a wavelength of 212 nanometers and an energy substantially equal to 800 millijoules / cm2.
7. Device according to claim 3, characterized in that the laser source (1) is a ruby ​​laser emitting radiation length equal to 694 nanometers, the second harmonic of a wavelength of 175.5 nanometers being selected using at least one double phosphate cell of ammonium and deuterium (ADP), KDP or KTP.
8. Device according to claim 4, characterized in that the laser source (1) consists of a phosphate laser emitting radiation whose wave length is 1054 nanometers, which is taken on the third harmonic which is mixed with a portion (25) of the original beam in a RAMAN tank (24) for obtaining a radiation whose wavelength is equal to 193 nanometers.
9. Device according to claim 1, characterized in that the space-device beam splitting is constituted by a set of at 'least four mirrors distributed symmetrically around the axis of the main beam (10)
10.A device according to claim 1, characterized in that the beam splitting means consist of a set of eight slots octagonal.
11.Device according to claim 10, characterized 'in that at least one conjugate mirror (26) is disposed in the path of the original beam.
12.Device according to one of claims 10 or 11, characterized in that means arranged on the cell outlet (22) collect in the optical path (25) a portion of the beam directed directly to the output stage ( 24) to form an aiming beam.
PCT/FR1986/000268 1985-07-31 1986-07-30 Device for ophthalmologic surgery by photoablation WO1987000748A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
FR85/11671 1985-07-31
FR8511671A FR2585558A1 (en) 1985-07-31 1985-07-31 Photoablation device
FR85/18171 1985-12-09
FR8518171A FR2591097A2 (en) 1985-12-09 1985-12-09 Photoablation device, in particular for corneal keratotomy

Publications (1)

Publication Number Publication Date
WO1987000748A1 true WO1987000748A1 (en) 1987-02-12

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PCT/FR1986/000268 WO1987000748A1 (en) 1985-07-31 1986-07-30 Device for ophthalmologic surgery by photoablation

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Cited By (11)

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WO1989006519A2 (en) * 1988-01-25 1989-07-27 Refractive Laser Research & Development Program, L Method and apparatus for laser surgery
EP0325836A2 (en) * 1988-01-21 1989-08-02 C.R. Bard, Inc. Laser tipped catheter
EP0402250A2 (en) * 1989-06-07 1990-12-12 University Of Miami Noncontact laser microsurgical apparatus
US5112328A (en) * 1988-01-25 1992-05-12 Refractive Laser Research & Development Program, Ltd. Method and apparatus for laser surgery
WO1993008877A1 (en) * 1991-11-06 1993-05-13 Lai Shui T Corneal surgery device and method
WO1994003134A1 (en) * 1992-08-03 1994-02-17 Sunrise Technologies, Inc. Method and apparatus for exposing a human eye to a controlled pattern of radiation spots
US5425729A (en) * 1985-10-18 1995-06-20 Kowa Company Ltd. Laser coagulation system
US5634922A (en) * 1989-11-20 1997-06-03 Hamamatsu Photonics K.K. Cancer diagnosis and treatment device having laser beam generator
WO1999008635A1 (en) * 1997-08-14 1999-02-25 Wallac Oy Medical laser guidance apparatus
US6241720B1 (en) * 1995-02-04 2001-06-05 Spectra Physics, Inc. Diode pumped, multi axial mode intracavity doubled laser
US6325792B1 (en) * 1991-11-06 2001-12-04 Casimir A. Swinger Ophthalmic surgical laser and method

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Laser Focus/Electro-Optics, Volume 21, No 5, March 1985, Littleton, Mass. (US) L. HOLMES: "Ophthalmic Treatments Exploit novel Laser/Tissue Interactions" pages 20,26,28 see pages 20,26,28 *

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5425729A (en) * 1985-10-18 1995-06-20 Kowa Company Ltd. Laser coagulation system
EP0325836A2 (en) * 1988-01-21 1989-08-02 C.R. Bard, Inc. Laser tipped catheter
EP0325836A3 (en) * 1988-01-21 1990-03-07 C.R. Bard, Inc. Laser tipped catheter
US5112328A (en) * 1988-01-25 1992-05-12 Refractive Laser Research & Development Program, Ltd. Method and apparatus for laser surgery
WO1989006519A3 (en) * 1988-01-25 1989-11-16 Refractive Laser Res & Dev Method and apparatus for laser surgery
WO1989006519A2 (en) * 1988-01-25 1989-07-27 Refractive Laser Research & Development Program, L Method and apparatus for laser surgery
EP0402250A2 (en) * 1989-06-07 1990-12-12 University Of Miami Noncontact laser microsurgical apparatus
EP0402250A3 (en) * 1989-06-07 1991-12-27 University Of Miami Noncontact laser microsurgical apparatus
US5634922A (en) * 1989-11-20 1997-06-03 Hamamatsu Photonics K.K. Cancer diagnosis and treatment device having laser beam generator
US6210401B1 (en) 1991-08-02 2001-04-03 Shui T. Lai Method of, and apparatus for, surgery of the cornea
US7220255B2 (en) 1991-08-02 2007-05-22 Lai Shui T Method and apparatus for laser surgery of the cornea
AU671607B2 (en) * 1991-11-06 1996-09-05 Shui T. Lai Corneal surgery device and method
WO1993008877A1 (en) * 1991-11-06 1993-05-13 Lai Shui T Corneal surgery device and method
US6325792B1 (en) * 1991-11-06 2001-12-04 Casimir A. Swinger Ophthalmic surgical laser and method
WO1994003134A1 (en) * 1992-08-03 1994-02-17 Sunrise Technologies, Inc. Method and apparatus for exposing a human eye to a controlled pattern of radiation spots
US6241720B1 (en) * 1995-02-04 2001-06-05 Spectra Physics, Inc. Diode pumped, multi axial mode intracavity doubled laser
WO1999008635A1 (en) * 1997-08-14 1999-02-25 Wallac Oy Medical laser guidance apparatus

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