WO2021033211A1

WO2021033211A1 - A real-time feedback device and system for ophthalmological procedure

Info

Publication number: WO2021033211A1
Application number: PCT/IN2020/050734
Authority: WO
Inventors: Rajeev Maruti Raut
Original assignee: Rajeev Maruti Raut
Priority date: 2019-08-22
Filing date: 2020-08-22
Publication date: 2021-02-25

Abstract

A real-time feedback device and system is disclosed herein, to analyse & inform the practitioner, during the ophthalmological procedure itself, of the corneal shape as well as the intended corneal shape to be achieved. The system comprises an image acquisition Module (10); a processor module (20); and a feedback module (30). The image acquisition module (10) captures the real-time image of the cornea, which is transferred to the processor module (20). The processor module (20) processes the real-time image to generate appropriate information related to the cornea in order to know intended interocular pressure for an appropriate point of incision. The feedback module (30), upon receiving the information, generates an appropriate real-time feedback signal to the practitioner, such that the practitioner is aware of the ideal shape of the cornea at the time of incision.

Description

A REAL-TIME FEEDBACK DEVICE AND SYSTEM FOR OPHTHALMOLOGICAL PROCEDURE

TECHNICAL FIELD OF THE INVENTION:

The present invention relates to a device and a system having real time feedback mechanism to achieve optimum corneal shape for desirable post-operative result, wherein the feedback is in the form of audio, visual or audio-visual. More particularly, the present invention relates to a system having real time continuous feedback mechanism which informs and assists the surgeon to achieve intended ideal corneal deformation, so that when the surgery is complete, the postoperative shape will be favourable for good visual outcome. The system may be used for cataract, glaucoma, corneal transplant or refractive surgery or any other eye surgery.

BACKGROUND AND PRIOR ART OF THE INVENTION:

A cornea is an elastic tissue likened to a slice of an elastic sphere. When incised for any intraocular procedures, it deforms. This deformation could hamper otherwise good eyesight post-surgery. In order to avoid the possible undesirable deformation of the cornea, the corneal shape can be manipulated during operative procedures such that it deforms in a favourable manner, thereby maintaining proper shape and good eyesight post-procedure.

There are certain devices that measure preoperative shape of the cornea, called “topographers”, which are based on analysing images reflected from the cornea with a known rings or shapes. There are devices, such as “scheimpflug system” wherein arriving at the knowledge about corneal shape done by video photography. There are also devices which guide the practitioner where to cut during surgery depending on preoperative topography.

US5909270 discloses surgical system for obtaining topographical maps of a cornea based on optic conoscopic holography wherein the topographic measurements are performed in "real time" and the measured topographic data can be used both for graphical display and feedback to the beam-steering controls of the system which stabilize the beam image at desired location. More particularly, US5909270 describes a system used in laser ablation of the cornea by a continuous feedback by a conoscopic topographer consisting of various optical ingredients which measures interference pattern then extracts a direct phase information of the target surface from the interference pattern by using a polynomial expansion. This information is used to create a probe laser beam, which is used to reshape the cornea in a procedure called photorefractive keratotomy. However, obtaining topographical information of the cornea in US’270 is based on an interference pattern by an optical birefringent medium which is the part of the system. US’270 fails to disclose real time continuous feedback mechanism which informs and assist the practitioner about intended ideal corneal deformation to be achieved so as to get good shape after incising the cornea.

US6419671 discloses optical feedback system which can be integrated into existing laser eye surgery systems to provide optical feedback regarding the progress of the changes in refractive characteristics of the eye, optionally allowing real-time measurements of the rate of change in quality of the ocular optical system of the eye during vision correction surgery. More particularly, the optical feedback system disclosed in US6419671 examines and analyses retinal images during treatment, measures refractive error of the eye during before and after surgery and allows adjustments during vision correction operation in photorefractive treatments. However, US6419671 does not describe real time continuous feedback mechanism which informs and assist the practitioner about intended accurate corneal deformation.

US20120310073 discloses an ophthalmological analysis for measuring an intraocular pressure in an eye using an analysis system, and to an analysis system of this type formed of an actuation device with which a cornea of the eye is deformed contactlessly, a puff of air being applied to the eye using the actuation device to deform the cornea, formed of a monitoring system with which the deformation of the cornea is monitored and recorded, sectional images of the undeformed and deformed cornea being recorded using the monitoring system, and formed of an analysis device with which the intraocular pressure is derived from the sectional images of the cornea.

The corrective procedure on cornea requires high degree of precision since the unintended deformation in cornea may reduce the vision, post-operation. There is no device which continuously guides the practitioner in real time to achieve intended ideal deformation of the cornea during the procedure. In view of this, it may be advantageous if the practitioner is able to obtain the knowledge of the specific spot where the cornea needs to be incised. It may be most advantageous if the practitioner receives the real time feedback during operative procedure to achieve ideal corneal shape.

SUMMARY OF THE INVENTION:

The present invention describes a feedback device and system that analyses and informs the practitioner, during the ophthalmological procedure itself, of the corneal shape as well as the intended corneal shape to be achieved. The said “manipulation” helps to achieve favourable deformation for good post-operative shape and good eyesight.

The said feedback device and system comprises an image acquisition module which is connected to a processor module; and a feedback module connected to the processor module.

The image acquisition module comprises of an illuminating ring and an image capturing & recording device. The image acquisition module is adapted to obtain the illuminated image of the cornea.

The processor module is adapted (i) to store and analyse the illuminated image of the cornea in real-time, (ii) to determine the extent of deformation of the cornea to be achieved prior to the operative procedure in order to get the best intended post incision corneal shape, (iii) to determine in real-time the extent of deformation of the cornea to be achieved during the operative procedure in order to get the best intended post incision corneal shape, and (iv) to process the information related to the intended deformation of the cornea to the feedback module. The feedback module is adapted to receive the real-time information from the processor module and generate an audio feedback or a visual feedback or an audio-visual or a tactile feedback to the practitioner. The said feedback enables the practitioner to achieve intended optimum deformation during incision. The present invention further discloses a method to obtain an ideal corneal shape using real time feedback device during eye correction procedure. The method comprises illuminating the cornea to obtain an image and transferring the said image to a processor module by means of an image acquisition module; processing the image in real-time by means of a processor module (20) in order to know an intended intraocular pressure to be applied to the cornea at an appropriate point of incision; and generating a feedback by means of a feedback generating module based on the processed real-time information from the processor module.

BRIEF DESCRIPTION OF DRAWINGS: The invention is further illustrated in the following drawings.

Figure 1A and Figure IB illustrates illuminating ring that forms a part of the image acquisition module.

Figure 2 illustrates a ring image of a cornea captured by an image acquisition module. Figure 3 illustrates a real-time retinal image of the cornea.

Figure 4 illustrate an angle of alfa and kappa forming at the center of the pupil. Figure 5A and Figure 5B illustrate a schematic representation of the real-time feedback device and system which includes an image acquisition module, a processor module; and a feedback module. DETAILED DESCRIPTION OF THE INVENTION:

The invention will now be described in detail with reference to certain preferred and optional embodiments, so that various aspects thereof may be more fully understood and appreciated. However, any skilled person will appreciate the extent to which such embodiments could be extrapolated in practice.

In the description, certain expression and terms have usual meaning. The “cornea”, as defined in the Background & Prior Art, is an elastic tissue of the eye, likened to a slice of an elastic sphere, and covers iris, pupil etc.

The expression “incision” is well known in medical professionals, which means a surgical cut made to the skin or flesh or any organs.

The “operative procedure” in the context of the present invention may be a surgical procedure. In the same context, the “ophthalmological procedure” may be any operative procedure in the field of ophthalmology. Further, the “operative procedure” included a manual, automated or a laser guided procedure.

The “practitioner” in the context of the present invention may be a surgeon or any other person who is qualified to perform operative procedures.

The present invention describes a feedback device and system that analyses and informs the practitioner, during the ophthalmological procedure itself, of the corneal shape as well as the intended corneal shape to be achieved in real time. The said “manipulation” helps to achieve favourable deformation for good post-operative shape and good eyesight.

The said feedback device and system comprises an image acquisition module which is connected to a processor module and a feedback module connected to the processor module. The image acquisition module comprises of an illuminating ring and an image capturing & recording device and is adapted to obtain the illuminated image of the cornea. At the time of the operative procedure, the illuminating ring is adjusted appropriately at the patient’s eye level, thereby generating the image of ring on the cornea due to reflection of the illuminated ring in the cornea. The said reflection is captured or recorded by the image capturing & recording device. The said image is sent to the processor module for further processing.

The processor module receives, stores and analyses the illuminated image of the cornea in real-time. The processor module is programmed to generate information of the cornea in more than ways. In one of the embodiment, the processor module determines the extent of deformation of the cornea to be achieved prior to the operative procedure in order to get the best intended post incision corneal shape. In a preferred embodiment, the processor module determines in real-time the extent of deformation of the cornea to be achieved during t e operative procedure in order to get the best intended post incision corneal shape. Thereafter, it processes the information related to the intended deformation of the cornea to the feedback module.

The feedback module is adapted to receive the real-time information from the processor module and generate an audio feedback or a visual feedback or an audio-visual feedback or tactile to the practitioner. The said feedback enables the practitioner to achieve intended optimum deformation during incision.

The instant invention is further explained in detail in the figures appended at the end of the specification. However, the figures illustrate best embodiment and is not intended to restrict the scope of the invention.

Figure 1 illustrates illuminating ring that forms a part of the image acquisition module. At the time of the operative procedure, the illuminating ring is adjusted appropriately at the patient’s eye level, thereby generating the image of ring on the cornea due to reflection of the illuminated ring in the cornea. The said reflection is captured or recorded by the image capturing & recording device. The said image is sent to the processor module for further processing. The captured image is illustrated in Figure 2. Further, by means of the existing devices, certain other parameters, such as retinal topography etc. are measured. The said data of the reflected image of the ring as well the other parameters is crucial for the processor to determine the best suited incision a surgeon or a practitioner must carry out in order to have optimum post-operative shape of the cornea.

Figure 3 illustrates a real-time retinal image of the cornea.

Figure 4 illustrate an angle of alfa and kappa forming at the center of the pupil. In corrective eye procedures, the measurement of angle kappa k is critical to obtain normal post-operative eyesight. The angle kappa k (44) indicates the shift between the actual visual axis (42) and the center of the pupil (41). The angle alfa a (43) denotes the overall tilt of the eye and lies about 6 mm posterior to the cornea. The measurement of the said angles is carried out before the incision of the eye. Apart from other aforementioned parameters, the values of these angles provides the surgeon / practitioner a valuable insight as to which angle the cornea needs to be cut. Consequent to providing feedback to the surgeon by the feedback module (30), the surgeon may proceed with incision. While attempting to cut the cornea with proper intraocular pressure for an appropriate point, the angles alpha and kappa are continuously being measured to give real-time feedback to the surgeon. Figure 5A and Figure 5B illustrate a schematic representation of the real-time feedback device and system which includes an image acquisition module (10), a processor module (20); and a feedback module (30). The image of the cornea is captured by the image acquisition module (10) to transfer it to the processor module (20). The expression “image” in the context of the present invention is not restricted to a photographic still image. The said expression also encompasses a video image, or any other image which can be analysed. The image acquisition module (10) comprises of an illuminating ring (11) and an image capturing & recording device (12). In a preferred embodiment, the illuminating ring (11) is an array of small lights arranged in a circular manner. However, the shape of the illuminating ring is any shape, for example oval shaped, which is convenient to illuminate cornea in order to capture a clear image. Further, the lights in the illuminating ring are selected from incandescent, LED, OLED or any other suitable lights. Furthermore, in the context of the present invention, the image capturing and recording device (12) may be any suitable device that can capture live images or video.

The captured image of the cornea is transferred to the processor module (20) for the analysis of the image, thereby producing a useful data by which the appropriate feedback is generated. The processor module (20) analyse the image by an image processing technique. During the analysis, the parameters such as, alpha angle a, kappa angle K, topography of the retina etc., are noted down by the processor module (20). By noting the value of the said parameters, a real-time feedback is generated by the feedback module (30) for the practitioner. The feedback is related to a proper intraocular pressure for an appropriate point for the practitioner, so as to retain the shape of the cornea as much as possible. Even during the operative procedure, the real-time feedback is generated for the practitioner in order for him/her to know whether the ideal shape of the cornea is achieved. The feedback may be audio, visual or audio-visual in nature.

The system may be used to minimise postoperative astigmatism. The system can be used to treat astigmatism that exists before surgery. The system may be used to reduce angle kappa, and angle alfa and align the visual axis to the center of the pupil to improve efficiency of photoreceptors.

Claims

aim,

1. A real-time feedback device and system to obtain an ideal corneal shape using real time feedback device during eye correction procedure which comprises of,

A. an image acquisition Module (10) adapted to obtain illuminated image of the cornea and to transfer the said image to a processor module (20);

B. a processor module (20) adapted to process the image in real-time in order to know intended intraocular pressure for an appropriate point of incision;

C. a feedback module (30) adapted to receive the real-time information from the processor module (20) and generate a feedback.

2. The device and system as claimed in Claim 1, wherein the processor module (20) is further adapted to (i) receive and store the illuminated image of the cornea in real-time, (ii) determine the extent of deformation of the cornea to be achieved prior to the operative procedure in order to get the best intended post incision corneal shape, (iii) determine in real-time the extent of deformation of the cornea to be achieved during the operative procedure in order to get the best intended post incision corneal shape, and (iv) to process the information related to the intended deformation of the cornea to the feedback module (30).

3. The device and system as claimed in Claim 1 , wherein the processor module (20) is adapted to measure alpha angle and kappa angle from the image received to determine deformation of cornea.

4. The device and system according to claim 1, wherein the Image Acquisition Module (10) comprises of an illuminating ring (11) and an image capturing & recording device (12).

5. The device and system according to claim 1, wherein the feedback generated by the Feedback Module (30) is selected from an audio feedback, a visual feedback, an audio-visual, a tactile feedback.

6. A method to obtain an ideal corneal shape using real time feedback device during eye correction procedure comprising: illuminating the cornea to obtain an image and transferring the said image to a processor module (20) by means of an image acquisition module (10); processing the image in real-time by means of a processor module (20) in order to know an intended intraocular pressure to be applied to the cornea at an appropriate point of incision; and generating a feedback by means of a feedback generating module (30) based on the processed real-time information from the processor module.

7. The method according to Claim 6, wherein the real-time processing of the image comprises steps of (i) to receive and store the illuminated image of the cornea in real-time, (ii) to determine the extent of deformation of the cornea to be achieved prior to the operative procedure in order to get the best intended post incision corneal shape, (iii) to determine in real-time the extent of deformation of the cornea to be achieved during the operative procedure in order to get the best intended post incision corneal shape, and (iv) to process the information related to the intended deformation of the cornea to the feedback module (30).

8. The method according to Claim 6, wherein the feedback generated is in the form of an audio feedback, a visual feedback, an audio-visual, or a tactile feedback.