Automated Selective Laser Trabeculoplasty
The automated SLT device addresses the inefficiencies of current procedures by using a loosely focused beam and large depth of field camera to expedite trabecular meshwork treatment, enhancing procedure speed and effectiveness.
Patent Information
- Application Number
- JP2025521115
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-10-11
- Filing Date
- 2023-10-09
- Publication Date
- 2025-10-17
AI Technical Summary
Current selective laser trabeculoplasty procedures are prolonged due to the need for precise focusing and realignment of the laser beam and surgical microscope, which taxes the operator's stamina and the patient's ability to maintain a fixed head position, leading to inefficiencies.
An automated SLT device with a gonioscope and scanner that uses a loosely focused beam with a small cone angle (≤2°) and a camera with a large depth of field, allowing for rapid alignment and treatment of the trabecular meshwork without frequent refocusing.
The device significantly reduces procedure duration by enabling rapid and effective treatment of the trabecular meshwork, minimizing the need for continuous focusing and realignment, thus improving operational efficiency.
Smart Images
Figure 2025534703000001_ABST
Abstract
Description
[Technical Field]
[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 414,919, filed October 11, 2022, which is incorporated herein by reference.
[0002] The present invention relates generally to devices and methods for treating the eye, and more particularly to laser trabeculoplasty. [Background technology]
[0003] Glaucoma is a group of eye diseases that lead to damage to the optic nerve. This damage is often caused by increased intraocular pressure (IOP) in the aqueous humor in the anterior chamber of the eye. This increased IOP can cause vision loss if left untreated.
[0004] One treatment used to lower IOP is selective laser trabeculoplasty (SLT), which is described, for example, in Gazzard et al., "Selective laser trabeculoplasty versus drops for newly diagnosed ocular hypertension and glaucoma: the LiGHT RCT" (NHS, volume 23, issue 31, June 2019, ISSN 1366-5278). In SLT, several laser shots are fired through the anterior chamber into the trabecular meshwork of the eye using a gonioscope. Laser irradiation of the trabecular meshwork improves drainage of aqueous humor through the meshwork, thus mitigating elevated IOP within the eye.
[0005] The term "optical radiation" is used in this specification and claims to refer to electromagnetic radiation in any of the visible, infrared and ultraviolet ranges of the spectrum. Summary of the Invention
[0006] The embodiments of the present invention described below provide improved devices and procedures for selective laser trabeculoplasty.
[0007] Thus, according to one embodiment of the present invention, there is provided an apparatus for a medical procedure. The apparatus includes a gonioscope having a distal surface configured to be positioned adjacent to a patient's eye, a proximal surface opposite the distal surface, and a plurality of facets extending between the distal and proximal surfaces. A camera is configured to capture an image of the anterior chamber of the eye through the proximal surface of the gonioscope, and a laser is configured to generate a beam of optical radiation. The apparatus further includes a scanner configured to direct a beam through the proximal surface of the gonioscope so that the beam reflects off the facets of the gonioscope into the anterior chamber and strikes tissue within the anterior chamber, and optics configured to focus the beam to strike tissue within the anterior chamber at a cone angle of 2° or less. A controller is configured to process the image of the anterior chamber to identify regions of the trabecular meshwork of the eye, and is configured to control the scanner to direct the beam to strike the identified regions at multiple locations around the periphery of the anterior chamber.
[0008] In one disclosed embodiment, the optics are configured to focus the beam so that the cone angle is less than 1.5°.
[0009] In a further embodiment, the camera has a depth of field sufficient to image the entire periphery of the anterior chamber through the gonioscope at a fixed focus setting. Typically, the optical system is configured to direct the beam to strike all of multiple positions on the periphery of the anterior chamber at a fixed focus setting. Alternatively or additionally, the depth of field of the camera is at least 4 mm. Further alternatively, the depth of field is at least 3 mm, 2 mm, or 1 mm.
[0010] In yet another embodiment, in the image captured by the camera, the periphery of the anterior chamber is divided into multiple segments by reflection of portions of the image from multiple facets of the gonioscope, and the processor is configured to stitch together the multiple segments to generate an output image in which areas of the trabecular meshwork appear as continuous bands.
[0011] In one disclosed embodiment, the distal face of the gonioscope includes a concave surface configured to contact the cornea of the eye. The device can include a suction ring that surrounds the gonioscope and is configured to maintain stable contact between the eye and the gonioscope.
[0012] There is also provided, in accordance with one embodiment of the present invention, a method for a medical procedure comprising positioning a distal face of a gonioscope proximate to a patient's eye, capturing an image of the anterior chamber of the eye through the gonioscope, processing the image of the anterior chamber to identify locations of trabecular meshwork within the eye, and directing a beam of optical radiation emitted by a laser through the proximal face of the gonioscope so that the beam reflects off a facet of the gonioscope into the anterior chamber and strikes the identified locations within the anterior chamber at a plurality of locations around the periphery of the anterior chamber, while focusing the beam to strike tissue within the anterior chamber at a cone angle of 2° or less.
[0013] According to one embodiment of the present invention, there is further provided a method for a medical procedure, comprising positioning a distal surface of a gonioscope proximate to a patient's eye and capturing an image of the anterior chamber of the eye through the gonioscope. The image of the anterior chamber is processed to identify a region of the trabecular meshwork within the eye. A beam of optical radiation emitted by a laser is directed through the proximal surface of the gonioscope such that the beam reflects off a facet of the gonioscope into the anterior chamber and impinges on the identified region within the anterior chamber at multiple locations on the periphery of the anterior chamber using a fixed focus setting of the beam at all multiple locations on the periphery of the anterior chamber.
[0014] In one disclosed embodiment, capturing an image of the anterior chamber includes capturing an image through a gonioscope at a fixed focus setting with a depth of field sufficient to image the entire periphery of the anterior chamber.
[0015] The present invention will be more fully understood from the following detailed description of the embodiments thereof, taken in conjunction with the drawings. [Brief explanation of the drawings]
[0016] [Figure 1] FIG. 1 is a schematic side view of an SLT device, according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram of an en face image of the anterior chamber of the eye captured by a camera through a gonioscope, according to one embodiment of the present invention. [Figure 3A] 1A-1C are schematic diagrams of segments of the anterior chamber angle at successive stages in the processing of a gonioscopic image, according to an embodiment of the present invention. [Figure 3B] 1A-1C are schematic illustrations of segments of the anterior chamber angle at successive stages of processing a gonioscopic image, according to an embodiment of the present invention. [Figure 3C] 1A-1C are schematic illustrations of segments of the anterior chamber angle at successive stages of processing a gonioscopic image, according to an embodiment of the present invention. [Figure 4A] 1 is a cross-sectional view of an eye showing the beam of the laser of the SLT device and showing the depth of field of the camera, according to one embodiment of the present invention. [Figure 4B] FIG. 1 is a partial front view of the eye showing the beam of the laser of the SLT device and illustrating the depth of field of the camera, according to one embodiment of the present invention. [Figure 5] 1 is a flow chart that schematically illustrates a method for performing an SLT procedure, in accordance with an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION
[0017] overview In an SLT procedure, the patient sits in front of the SLT machine, which is aligned with the patient's eye. The patient must maintain a fixed head position and orientation relative to the SLT machine while the laser beam is focused on and moved across the trabecular meshwork by the operating ophthalmologist. As with other laser surgical procedures, the laser beam is precisely focused on each point in the trabecular meshwork to be treated, as indicated by the sharp focus of the aiming beam through the operating microscope. (The proper location of the treatment beam coincides with the focus of the operating microscope.) Due to irregularities in the eye and irregularities in the positioning of the gonioscope, the focus position often changes over time. Furthermore, the microscope used by the ophthalmologist to view the gonioscope image must be refocused to ensure the laser beam is properly aimed and focused. The firing of multiple laser pulses into the trabecular meshwork, while simultaneously aligning and focusing the surgical microscope and laser beam, prolongs the procedure and taxes the stamina of the operating ophthalmologist, as well as the ability of the patient to hold their head in a fixed position and orientation.
[0018] Therefore, there is a need to automate SLT procedures to reduce their duration while ensuring their effectiveness. The embodiments of the present invention described herein address this issue by using a laser that emits a loosely focused beam with a small cone angle, e.g., less than 2°. This innovation is based on the recognition that the effectiveness of laser trabeculectomy does not depend on creating a precise intensity in the trabecular meshwork. The use of a loosely focused beam in this embodiment increases the depth of field for the laser beam, thus reducing the requirements for focusing the beam and speeding up the procedure. Under these conditions, the same focus setting is generally used throughout the entire periphery of the anterior chamber. This arrangement also allows for the use of a camera with a large depth of field for laser beam alignment.
[0019] Thus, the disclosed embodiments provide an apparatus for a medical procedure, including a gonioscope having a distal surface configured for placement adjacent to a patient's eye, a proximal surface opposite the distal surface, and a plurality of facets extending between the distal and proximal surfaces. A camera captures an image of the anterior chamber of the eye through the proximal surface of the gonioscope. A laser generates a beam of optical radiation, and a scanner directs the beam through the proximal surface of the gonioscope so that the beam reflects off the facets of the gonioscope into the anterior chamber and strikes tissue within the anterior chamber. An optical system focuses the beam to strike tissue within the anterior chamber at a cone angle of 2° or less, preferably 1.5°. A controller processes the image of the anterior chamber to identify regions of the trabecular meshwork within the eye and controls the scanner to direct the beam to strike the identified regions at multiple locations around the periphery of the anterior chamber.
[0020] System Description FIG. 1 is a schematic side view of a partially automated SLT device 100 according to one embodiment of the present invention.
[0021] The SLT device 100 comprises an optical unit 102, an XYZ stage 104, and a base unit 106. The optical unit 102 comprises a treatment laser 108 that emits a treatment beam 113 of optical radiation and an optional low-intensity integral collinear aiming beam 107, which may include its separate focusing optics (not shown). The optical unit also comprises a scanner 110, a camera 112, a camera lens 114, a fixed point 109, and a beam combiner 116 that combines the optical paths of the laser 108 and the camera 112. The focusing optics 111 focuses the treatment beam 113 emitted by the laser 108 and scanned by the scanner 110 into a focused treatment beam 117 with a cone angle of 2° or less. In an alternative embodiment, the cone angle α may be limited by the optics 111 to 1.5° or less. In an alternative embodiment, optics 111 may be positioned between laser 108 and scanner 110 to focus beam 113. Optics 111 may also include a focus adjustment mechanism.
[0022] In this embodiment, laser 108 comprises a frequency-doubled Nd:YAG Q-switched laser emitting pulses at a wavelength of 532 nm with pulse durations in the range of 1-10 nanoseconds, pulse frequencies in the range of 1-100 Hz, and pulse energies in the range of 0.2 mJ-2.6 mJ. Alternatively, any other suitable type of laser operating in either pulsed or CW mode may be used.
[0023] The optical unit 102 further includes a gonioscope 118 having a plurality of reflective facets 119 arranged in a frustum between a distal surface 120 and a proximal surface 121, and an illumination ring 122. In the examples shown in the following figures, the gonioscope has four or six facets, but the gonioscope may alternatively have any suitable number of facets or may have a continuous curved shape. The distal surface 120 is concave and, in certain embodiments, is surrounded by a suction ring 123 to maintain stable contact between the patient's eye and the gonioscope. The gonioscope 118 is collinear with and centered on the optical axis 127 of the camera 112.
[0024] Scanner 110 comprises two galvanometer mirrors 124 and 125 that rotate about two orthogonal axes (not shown for simplicity), the rotation being indicated by circular arrows 126 and 128, respectively. Scanner 110 is configured to direct beam 117 through the proximal surface of gonioscope 118 such that the beam reflects from gonioscope facet 119 through distal surface 120 into anterior chamber 129 (FIG. 4A) of eye 142 in contact with the distal surface to strike tissue within the anterior chamber.
[0025] The XYZ stage 104 moves the optical unit 102 in three linear orthogonal X, Y, and Z directions, as indicated by Cartesian coordinates 130 .
[0026] The base unit 106 comprises a controller 132 and a monitor and user control unit 134. The controller 132 is coupled to the camera 112, the laser 108, the scanner 110, the XYZ stage 104, and the monitor and user control unit 134. Alternatively, the monitor and / or the entire user control unit 134, and / or the controller may be integrated into the optical unit 102.
[0027] Controller 132 typically comprises a programmable processor that is programmed with software and / or firmware to perform the functions described herein. Alternatively or additionally, controller 132 comprises hardwired and / or programmable hardware logic circuitry that performs at least some of the functions of the controller. While controller 132 is shown in the figures as a single monolithic functional block for simplicity, in practice the controller may comprise a single chip or a set of two or more chips with appropriate interfaces for receiving and outputting the signals shown in the figures and described herein.
[0028] The monitor and user control unit 134 includes one or more visual displays and suitable input devices, such as a keyboard, joystick, and / or mouse, to enable an operator 136 to interact with the SLT apparatus 100. (For simplicity, details of the monitor and user control unit 134 have been omitted from the figures.)
[0029] For an SLT procedure, the patient positions their head 140 in front of the optical unit 102 so that their eye 142 is in proximity to the distal face 120 of the gonioscope 118. The device 100 typically includes a chin rest 144 and a forehead rest 146 to increase stability of the patient's head 140 during the procedure. The chin rest 144 and forehead rest 146 may be integrated into the base unit 106 or may be attached to the table of the device 100. A fixation point 109 is provided for the patient to align and stabilize their eye 142.
[0030] The operator 136 observes the eye 142 in the image captured by the camera 112 and displayed on the monitor of the unit 134. For this purpose, the eye 142 can be illuminated, for example, by the illumination ring 122, although other types of light sources can alternatively be used. The camera 112, together with the lens 114, has a depth of field sufficient to image the entire periphery of the anterior chamber 129 of the eye 142 with a single focus setting of the camera. While observing the eye, the operator 136 moves the optical unit 102 in the X and Y directions by means of an input device such as a joystick so that the optical axis 127 of the camera 112 is aligned with the eye 142. The operator 136 then moves the optical unit 102 in the Z direction to bring the concave surface of the distal surface 120 into contact with the cornea of the eye 142 ( FIG. 4A ). A gel or other suitable contact material may be applied to the cornea 149 prior to contact. In certain embodiments, the suction ring 123 maintains stable contact between the eye 142 and the gonioscope 118 .
[0031] After the above-described alignment process, the operator 136 fine-tunes the XY position of the optical unit 102 to center the eye 142 in the field of view of the camera 112 and image the full 360° field of view (e.g., as shown in FIG. 2). The same fixed focus setting is used around the entire periphery of the anterior chamber 129, eliminating the need to refocus the camera 112 at various points around the periphery, even if the image is not perfectly sharp at all points. As described in further detail below with reference to FIGS. 3A-3C , the controller 132 identifies a site on the trabecular meshwork of the eye 142 in the image captured by the camera 112 and then instructs the scanner to direct the beam 117 to strike the trabecular meshwork at multiple locations around the periphery of the anterior chamber during the procedure. Prior to actually firing the laser 108, the operator 136 uses the aiming beam 107 displayed on the monitor to verify the location of the site 308 on the trabecular meshwork and the alignment of the laser. Once the laser 108 is activated to emit the beam 113, a typical treatment takes less than a minute, and may take just a few seconds, using a pulse frequency of 50-100 Hz and a pulse energy of approximately 1 mJ. Prior to emitting the treatment beam 113, the aiming beam 107 may be swept over the target point, a motion verified by the operator 136 before proceeding to treatment mode.
[0032] FIG. 2 is a schematic illustration of an en face image 200 of the anterior chamber of eye 142 captured by camera 112 through gonioscope 118, according to one embodiment of the present invention.
[0033] Image 200 comprises both a direct image 202 of the anterior chamber and a reflected image 204 reflected by facets 119 of gonioscope 118. In the embodiment shown in FIG. 2, gonioscope 118 comprises six reflective facets 119, although in alternative embodiments the number of facets 119 may be more or less than six, such as four, eight, twelve, or any other number of facets.
[0034] The direct image 202 comprises an image of the iris 206 and pupil 208 of the eye 142, without reflections from the facets 119. Each reflected image 204 may include a partial iris image 212 and a partial pupil image 210. Additionally, each reflected image 204 comprises an image segment 214 of the anterior chamber angle (as shown in FIG. 4A ), which corresponds to the location of a respective portion of the trabecular meshwork. The large depth of field of the camera 112 allows the image segments 214 reflected by each facet 119 to be well focused on the camera simultaneously in all reflected images 204, allowing a weakly focused treatment beam 117 to be directed at various portions of the anterior chamber angle, eliminating the need to refocus the camera and thus expediting treatment. However, as described in further detail below with reference to FIG. 3A , the optical structure of the gonioscope 118 distorts and separates the image segments 214 from one another.
[0035] 3A-3C schematically illustrate an image segment 302 of the anterior chamber angle 216 spanning a 360° circumference at three respective stages of processing of an image captured by the camera 112, according to one embodiment of the present invention.
[0036] 3A shows image segments 302 of the anterior chamber angle 216 captured through a gonioscope (similar to gonioscope 118, but with four reflective facets). The trabecular meshwork 150 of the eye is located within the angle 216. As shown in FIG. 2 above, the image segments 302 captured by camera 112 are distorted from their actual shape and are separated from one another.
[0037] FIG. 3B is a schematic image 304 of a (generally) elliptical sequence of images of the anterior chamber angle 216 and trabecular meshwork 150, with the controller 132 having image segments 302 that have been undistorted and stitched together to identify the location of the trabecular meshwork.
[0038] 3C is a schematic image 306 in which controller 132 has identified a region 308 (dotted line) of trabecular meshwork 150 along the periphery of the anterior chamber. Controller 132 controls laser 108 and scanner 110 to emit and direct laser beam 117 to strike the trabecular meshwork at multiple locations around region 308.
[0039] 4A and 4B schematically illustrate a cross-sectional partial view 404 and a front partial view 414 of the eye 142, showing the beam 117 of the laser 108 and illustrating the depth of field 402 of the camera 112, according to one embodiment of the present invention.
[0040] 4A includes an anterior portion 406 of the eye 142. The anterior portion 406 includes the iris 206, the pupil 208, the cornea 149, the anterior chamber 129 (filled with aqueous humor), the lens 412, and the trabecular meshwork 150 of the eye 142. (Additional structures in the anterior portion 406 in the figure are not relevant to the current discussion and, for simplicity, are left unlabeled.) The angle 216 of the anterior chamber angle 149 is located between the cornea 149 and the iris 206 and includes the trabecular meshwork 150. The cross-sectional view 404 further includes a partial cross-section of the gonioscope 118, showing two facets 119 and a portion of the distal surface 120.
[0041] Beam 117 of laser 108 reflects off one of the facets 119 of gonioscope 118 and strikes trabecular meshwork 150 through cornea 149 and anterior chamber 129 (for clarity, refraction is ignored). A low value of cone angle α (less than 3°) ensures that beam 117 has a sufficient spot size to deliver laser energy to sufficient depth into trabecular meshwork 150 throughout the entire 360° circumference without the need to refocus laser 108 during the procedure.
[0042] The camera 112 focuses on the anterior chamber angle 26 and the trabecular meshwork 150 with a depth of field 402 sufficient to capture the entire image 200 ( FIG. 2 ) with a single focus setting of the camera. For example, the depth of field may be greater than 1 mm, or greater than 2 mm, or greater than 3 mm, or greater than 4 mm, or even greater than 5 mm. The depth of field 402 is related to the size of the circle of confusion of the camera 112, and in this case, depth of field is meant to refer to the ability of the controller 132 to direct the focused treatment beam 117 toward the trabecular meshwork 150 even if the trabecular meshwork is not in sharp focus when viewed by the operator 136.
[0043] The front view 414 of FIG. 4B shows the trabecular meshwork 150 and anterior chamber angle 216 depicted in the XY plane of Cartesian coordinates 130, indicated in the diagram by the X and Y axes 420. For this two-dimensional representation, the depth of field 402 of the laser beam 117 and camera 112 is shown with their Z directions flattened and reshaped into a circle in the XY plane. The small cone angle α of the beam 117 defines a treatment region 416 extending through the trabecular meshwork 150, with a typical laser spot size S of 0.4 mm. As an example, a cone angle α of 1.5° results in a depth D of 3 mm in the region 416, with a ±10% variation in spot size across the region. The depth of field 402 of the camera 112 may be 2 mm, 3 mm, 4 mm, or more. By making the camera depth of field 402 equal to or greater than the laser depth of focus D, it is ensured that for a focused image of the camera 112, the beam 117 is also focused.
[0044] FIG. 5 is a flow chart 500 that schematically illustrates a method for performing an SLT procedure using the SLT device 100, in accordance with one embodiment of the present invention.
[0045] The procedure begins at a start step 502. In a head positioning step 504, the patient positions their head 140 near the gonioscope 118 (FIG. 1). In an alignment step 506, the operator 136 aligns the optical unit 102 with the eye 142 in the XY plane. In a Z movement step 508, the operator 136 moves the optical unit 102 in the Z direction to bring the cornea 149 of the eye 142 into contact with the distal surface 120 of the gonioscope 118. In a centering and focusing step 510, the operator 136 centers and focuses the optical unit 102 to position the eye 142 at or near the center of the field of view of the camera 112. In an image capture step 512, the operator 136 captures an image of the eye 142 with the camera 112 through the gonioscope 118.
[0046] In image processing step 514, controller 132 processes the captured image to define region 308 on trabecular meshwork 150 (FIG. 3C). In target verification step 516, operator 136 views region 308 on trabecular meshwork 150. Aiming beam 107 is fired around some or all of the target point and may be displayed on monitor 134 to verify correct laser operation. As long as the region coincides with the trabecular meshwork, operator 136 fires laser 108 to hit multiple points around the region in firing step 518. (If the region identified by the controller does not coincide with the trabecular meshwork 150, operator 136 can instruct SLT device 100 to return to centering and focusing step 510 or manually adjust the region.) The SLT procedure ends in end step 520.
[0047] It will be understood that the above-described embodiments are cited by way of example, and that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof not disclosed in the prior art, which will occur to those skilled in the art upon reading the foregoing description.
Claims
1. a gonioscope having a distal surface configured to be positioned proximate to a patient's eye, a proximal surface opposite the distal surface, and a plurality of facets extending between the distal and proximal surfaces; a camera configured to capture an image of the anterior chamber of the eye through the proximal surface of the gonioscope; a laser configured to generate a beam of optical radiation; a scanner configured to direct the beam through the proximal surface of the gonioscope such that the beam reflects off a facet of the gonioscope into the anterior chamber and strikes tissue within the anterior chamber; an optical system configured to focus the beam to impinge on the tissue in the anterior chamber at a cone angle of 2° or less; a controller configured to process the image of the anterior chamber to identify regions of the trabecular meshwork of the eye, and configured to control the scanner to direct the beam to strike the identified regions at a plurality of locations around a periphery of the anterior chamber; 1. An apparatus for a medical procedure comprising:
2. The apparatus of claim 1 , wherein the optical system is configured to focus the beam so that the cone angle is less than 1.5°.
3. The device of claim 1 , wherein the camera has a depth of field sufficient to image the entire periphery of the anterior chamber through the gonioscope at a fixed focus setting.
4. 4. The device of claim 3, wherein the optical system is configured to direct the beam to strike all of the plurality of locations on the periphery of the anterior chamber at the fixed focus setting.
5. The apparatus of claim 3 , wherein the depth of field of the camera is at least 1 mm.
6. The apparatus of claim 5 , wherein the depth of field of the camera is at least 2 mm.
7. The apparatus of claim 6 , wherein the depth of field of the camera is at least 3 mm.
8. The apparatus of claim 7 , wherein the depth of field of the camera is at least 4 mm.
9. 4. The apparatus of claim 3, wherein in the image captured by the camera, the periphery of the anterior chamber is divided into a plurality of segments by reflection of portions of the image from the plurality of facets of the gonioscope, and the processor is configured to stitch together the plurality of segments to generate an output image in which the portion of the trabecular meshwork appears as a continuous band.
10. The apparatus of any one of claims 1 to 9, wherein the distal surface of the gonioscope comprises a concave surface configured to contact the cornea of the eye.
11. 11. The device of claim 10, comprising a suction ring surrounding the gonioscope and configured to maintain stable contact between the eye and the gonioscope.
12. positioning a distal surface of a gonioscope adjacent to the patient's eye; capturing an image of the anterior chamber of the eye through the gonioscope; processing the image of the anterior chamber to identify a location of a trabecular meshwork within the eye; directing a beam of optical radiation emitted by a laser through a proximal surface of the gonioscope so that the beam reflects off a facet of the gonioscope into the anterior chamber and strikes the identified site within the anterior chamber at a plurality of locations around the periphery of the anterior chamber, while focusing the beam to strike tissue within the anterior chamber at a cone angle of 2° or less; 10. A method for medical treatment comprising:
13. 13. The method of claim 12, wherein the cone angle of the beam impinging on the tissue is less than 1.5 degrees.
14. 13. The method of claim 12, wherein capturing the image of the anterior chamber comprises capturing the image with a depth of field sufficient to image the entire periphery of the anterior chamber through the gonioscope at a fixed focus setting.
15. 15. The method of claim 14, wherein focusing the beam comprises using the fixed focus setting to direct the beam at all of the multiple locations on the periphery of the anterior chamber.
16. The method of claim 15, wherein the depth of field is at least 1 mm.
17. The method of claim 16, wherein the depth of field is at least 2 mm.
18. 18. The method of claim 17, wherein the depth of field is at least 3 mm.
19. 20. The method of claim 18, wherein the depth of field is at least 4 mm.
20. 15. The method of claim 14, wherein in the captured image, the periphery of the anterior chamber is divided into a plurality of segments by reflection of portions of the image from the plurality of facets of the gonioscope, and wherein processing the image includes stitching the plurality of segments together to generate an output image in which the portion of the trabecular meshwork appears as a continuous band.
21. The method of any one of claims 12 to 20, wherein the distal surface of the gonioscope includes a concave surface configured to contact the cornea of the eye.
22. 22. The method of claim 21, including providing a suction ring that surrounds the gonioscope and maintains stable contact between the eye and the gonioscope.
23. positioning a distal surface of a gonioscope adjacent to the patient's eye; capturing an image of the anterior chamber of the eye through the gonioscope; processing the image of the anterior chamber to identify a location of a trabecular meshwork within the eye; directing a beam of optical radiation emitted by a laser through a proximal surface of the gonioscope such that the beam reflects off a facet of the gonioscope into the anterior chamber and impinges on the identified site within the anterior chamber at a plurality of locations around the periphery of the anterior chamber using a fixed focus setting of the beam at all of the plurality of locations around the periphery of the anterior chamber; 10. A method for medical treatment comprising:
24. 24. The method of claim 23, wherein capturing the image of the anterior chamber comprises capturing the image with a depth of field sufficient to image the entire periphery of the anterior chamber through the gonioscope at the fixed focus setting.