Direct selective laser trabeculoplasty

Abstract

To provide ophthalmic devices and methods for treating glaucoma, ocular hypertension (OHT), and other diseases. [Solution] The system (20) comprises a radiation source (48) and a controller (44), the controller being configured to: display a live sequence of images of the patient's (22) eye (25); while displaying the sequence of images of the eye, to direct the radiation source to irradiate the eye with one or more targeting beams (84) visible in the images; after directing the targeting beams to the eye with the radiation source, to receive confirmation input from the user; and in response to receiving confirmation input, to treat the eye by directing the radiation source to irradiate each target area of ​​the eye with multiple treatment beams. Other embodiments are also described.

Description

Technical Field

[0001] The present invention relates to ophthalmic devices and methods for treating glaucoma, ocular hypertension (OHT), and other diseases.

[0002] (Cross - reference to related applications) This application claims the benefit of (i) U.S. Provisional Patent Application No. 62 / 692,868, titled "Direct Selective Laser Trabeculoplasty Process (DSLT) and Safety", filed on July 2, 2018 (Patent Document 1); (ii) U.S. Provisional Patent Application No. 62 / 739,238, titled "Eye Tracking Flash Illumination", filed on September 30, 2018 (Patent Document 2); and (iii) U.S. Provisional Patent Application No. 62 / 748,461, titled "Cross - ranging Beam", filed on October 21, 2018 (Patent Document 3). The entire disclosure of each of those respective references is incorporated herein by reference.

Background Art

[0003] In trabeculoplasty, a radiation source irradiates the trabecular meshwork of a patient's eye with one or more treatment beams to reduce intraocular pressure.

[0004] Geffen, Noa, et al., "Scleral Selective Laser Trabeculoplasty without a Keratoscope", Journal of glaucoma 26.3 (2017): 201 - 207 (Non - Patent Document 1) describes a study investigating the results of selective laser trabeculoplasty (SLT) performed directly on the sclera without a keratoscope.

[0005] Belkin's U.S. Patent Application Publication 2015 / 0366706 (Patent Document 4), whose disclosure is incorporated herein by reference, describes an apparatus comprising a probe and a processor. The probe is positioned adjacent to the patient's eye and configured to irradiate one or more light beams onto the trabecular meshwork of the eye. The processor is configured to select one or more target regions of the trabecular meshwork and to control the probe to irradiate the selected target regions with light beams. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] U.S. Provisional Patent Application No. 62 / 692,868 [Patent Document 2] U.S. Provisional Patent Application No. 62 / 739,238 [Patent Document 3] U.S. Provisional Patent Application No. 62 / 748,461 [Patent Document 4] U.S. Patent Application Publication No. 2015 / 0366706 [Non-patent literature]

[0007] [Non-Patent Document 1] Geffen, Noa, et al., "Transscleral Selective Laser Trabeculoplasty Without Corneal Lens," Journal of Glaucoma 26.3(2017):201-207. [Overview of the Initiative]

[0008] According to some embodiments of the present invention, a system is provided having a radiation source and a controller. The controller is configured to: display a live sequence of images of a patient's eye and, while displaying the sequence of images of the eye, to direct the radiation source to irradiate the eye with one or more targeting beams visible in the images. The controller is further configured to receive confirmation input from the user after directing the targeting beams to the eye with the radiation source and, in response to receiving the confirmation input, to treat the eye by directing the radiation source to irradiate each target area of ​​the eye with multiple therapeutic beams.

[0009] In some embodiments, the system further comprises a focusing lens and one or more beam-directing elements, wherein the controller is configured to direct a therapeutic beam from a radiation source toward the beam-directing elements via the focusing lens, thereby irradiating the eyes with the therapeutic beam, so that the beam is focused by the focusing lens before being directed toward the respective target areas by the beam-directing elements.

[0010] In some embodiments, the aiming beam collides with at least a portion of each target area. In some embodiments, the controller is further configured to superimpose markers that pass through each target region onto each image. In some embodiments, the marker is elliptical. In some embodiments, at least a portion of each target region is located within 1 mm of the limbus.

[0011] In some embodiments, the controller is further configured to: overlay one marker on each image and process the images before treating the eye to determine the position of each aiming beam relative to the marker, where the controller is configured to treat the eye in response to the determination of the aiming beam's position. In some embodiments, the controller is configured to determine the position of the aiming beam by confirming that the aiming beam overlaps with a marker.

[0012] In some embodiments, the controller is configured to determine the position of the aiming beam by confirming that the aiming beam is outside the marker. In some embodiments, the controller is configured to treat the eye such that each edge of the treatment beam collides with each portion of the eye over which the marker is superimposed. In some embodiments, the marker is elliptical.

[0013] In some embodiments, the controller is further configured to: display a still image of an eye before displaying a live image; identify the elliptical portion of the eye in the still image based on user input; and, in response to the identification of the elliptical portion of the eye, overlay an elliptical marker on the elliptical portion of the eye in each image.

[0014] In some embodiments, the controller is configured to superimpose an elliptical marker onto the elliptical portion of the eye by: identifying the elliptical portion of the eye, then identifying the deviation from the center of the limbus of the eye to the center of the elliptical portion of the still image; for each image: identifying the center of the limbus in the image; and superimposing the elliptical marker onto the image such that the center of the elliptical marker is the deviation identified from the center of the limbus.

[0015] In some embodiments, the controller is configured to identify the elliptical portion of an eye by: displaying (i) an elliptical marker and (ii) a rectangle circumscribing the elliptical marker on a still image; and, after displaying the elliptical marker and the rectangle, adjusting the elliptical marker in response to user adjustment of the rectangle, so that the elliptical marker maintains its circumscribing position with the rectangle until the elliptical marker overlaps the eye portion. In some embodiments, the controller is further configured to identify the limbus of the eye in a still image, and the controller is configured to display an elliptical marker on the limbus.

[0016] In some embodiments, the system further comprises a camera configured to acquire an image and, prior to acquiring the image, acquire a static image of an eye, wherein the controller is further configured to: identify a static region within the field of view of the camera that includes the pupil of the eye based on the static image of the eye, and treat the eye such that each treatment beam impinges on the eye outside the static region.

[0017] In some embodiments, the system further comprises one or more beam steering elements, wherein the controller is configured to sequentially direct the beam steering elements towards a target region and treat the eye by emitting a treatment beam to the beam steering element, wherein the controller is further configured to prohibit the beam steering element from being directed towards the static region even when no treatment beam is being emitted. In some embodiments, the controller is configured to identify the static region by: receiving from the user a corneal limbus position identification input indicating the position of the corneal limbus in the static image; and identifying the static region based on the position of the corneal limbus.

[0018] In some embodiments, the image is a first image and the aiming beam is a first aiming beam, wherein the system further includes a camera configured to acquire a plurality of second images of the eye while treating the eye, wherein the controller is configured to iteratively: check the position of each second aiming beam in the second image; and in response to the check, emit each one treatment beam towards the eye.

[0019] In some embodiments, the controller is configured to check the position by verifying that the distance between each second aiming beam and each one target region is less than a predetermined threshold. In some embodiments, the controller is configured to emit each one treatment beam towards each one target region. In some embodiments, it further comprises an illumination source, wherein the controller is further configured to intermittently flash visible light towards the eye so as to illuminate the eye, at least during the acquisition of each second image, for the illumination source.

[0020] In some embodiments, the peak average intensity of the light over the duration of each flash is between 0.003 - 3 mW / cm 2 thereof. In some embodiments, the controller is configured to flash the light for the illumination source at a frequency of at least 60 Hz. In some embodiments, the frequency is at least 100 Hz. In some embodiments, the controller is further configured for the illumination source to illuminate the eye with near-infrared light, at least during the acquisition of each second image.

[0021] In some embodiments, the controller is further configured to intermittently flash visible light towards the eye for the illumination source while treating the eye. In some embodiments, it further comprises an optical unit including a radiation source and a plurality of beam emitters, wherein the controller is further configured to irradiate a plurality of distance measurement beams towards the eye for the beam emitters before irradiating a aiming beam towards the eye for the radiation source, and the distance measurement beams are shaped to define different respective portions of a predefined composite pattern, whereby the predefined composite pattern is formed over the eye only when the optical unit is at a predetermined distance from the eye.

[0022] In some embodiments, the distance measurement beams are shaped to define two perpendicular shapes, and the predefined composite pattern includes a cross. In some embodiments, it further comprises an optical unit including a radiation source, and the controller is configured to irradiate a target area for the radiation source while the optical unit is directed obliquely upward towards the eye and the eye is positioned obliquely downward towards the optical unit. In some embodiments, a wedge is further provided, and the optical unit is oriented diagonally upward toward the eye by being attached to the wedge.

[0023] According to some embodiments of the present invention, a system is provided comprising: a wedge; an optical unit mounted on the wedge so as to be oriented diagonally upward, the optical unit including a radiation source; and a controller configured to treat a patient's eye by directing the radiation source to each target area of ​​the eye while the eye is fixed diagonally downward toward the optical unit.

[0024] According to some embodiments of the present invention, a method is provided comprising: displaying a live sequence of images of a patient's eye; irradiating the eye with one or more visible targeting beams within the images while displaying the sequence of images; receiving confirmation input from a user following the step of irradiating the eye with the targeting beams; and treating the eye by irradiating each target area of ​​the eye with a plurality of therapeutic beams in response to the receipt of the confirmation input. [Brief explanation of the drawing]

[0025] The present invention will be better understood from the following detailed description of its embodiments with reference to the drawings: [Figure 1] This is a schematic diagram of a system for performing trabeculoplasty according to several embodiments of the present invention. [Figure 2] This is a schematic diagram of a fiber trabecular strip forming apparatus according to several embodiments of the present invention. [Figure 3] This is a schematic diagram of a pretreatment procedure according to several embodiments of the present invention. [Figure 4] This is a schematic diagram of an exemplary algorithm for performing an automated trabeculoplasty procedure according to some embodiments of the present invention. [Modes for carrying out the invention]

[0026] (overview) Embodiments of the present invention provide an automated trabeculoplasty apparatus configured to safely and efficiently perform a trabeculoplasty procedure on the eye. The trabeculoplasty apparatus includes a controller and an optical unit comprising a radiation source, a camera, and a beam-directing element. As described in detail below, the controller is configured to control the radiation source and the beam-directing element in response to feedback from the camera, and the beam-directing element directs the beam of radiation emitted by the radiation source to the appropriate location in the eye. The emitted radiation beam includes both a therapeutic beam that irradiates the trabecular meshwork of the eye and a aiming beam used to assist in aiming the therapeutic beam.

[0027] Typically, before the procedure, the controller displays a live video of the eye with two ellipses superimposed on it: an inner ellipse showing the limbus of the eye, and an outer ellipse, a small distance offset from the inner ellipse, passing through or near each target area to be irradiated by the treatment beam. The controller then simulates the procedure by sweeping the targeting beam over the outer ellipse, usually so that the targeting beam collides with at least a portion of each target area. Advantageously, this simulation can help the physician visualize the path along the eye that will be targeted by the treatment beam—that is, the path in which the target areas lie. Once the physician has confirmed the target path along the eye, the controller causes the radiation source to emit the treatment beam toward the target areas.

[0028] Since each beam of radiation generally strikes the eye with a non-microspot size, it should be noted that this application generally describes each beam as striking an "area" of the eye, whose area is a function of the spot size, and not a "point" of the eye. Therefore, for example, this application relates to a "target area" rather than a "target point." Nevertheless, in the context of this application, including the claims, reference to calculating the location of a target area may implicitly refer to calculating the location of the area by calculating the location of a single point within the area, such as the center or end of the area to which the center or end of the beam (each) is directed. (Even if the center or end of the beam is then slightly off from the calculated point, this application, including the claims, may consider the beam to have struck the calculated target area.)

[0029] Typically, before simulating the above procedure, the controller acquires a still image of the eye and identifies the limbus in the still image. The controller then superimposes the aforementioned inner ellipse onto the limbus. Subsequently, the controller allows the physician to change the position and / or shape of the inner ellipse, so that the inner ellipse marks the limbus as defined by the physician. (Because the limbus is not generally clearly defined, the location of the limbus may differ slightly from the location automatically identified by the controller for each physician.) For example, the controller may enclose the inner ellipse with a rectangle and allow the physician to adjust the ellipse by dragging the sides or corners of the circumscribing rectangle.

[0030] As the inventors have observed, the trabecular meshwork can be most effectively irradiated when the therapeutic beam strikes the limbus of the eye or near it, and the limbus can be identified by the user as described above or automatically identified by the controller. Therefore, in some embodiments of the present invention, the controller causes the radiation source to target the limbus or a portion of the eye near the limbus. For example, at least a portion of each target area may be located within 1 mm (e.g., within 400 microns) of the limbus. In the particular example above, the center of each target area is located within 1 mm (e.g., within 400 microns) of the limbus, so that the center of each therapeutic beam can strike the eye within 1 mm (e.g., within 400 microns) of the limbus.

[0031] In both simulated and actual procedures, the camera acquires images of the eye at relatively high frequencies (e.g., frequencies above 40 Hz or 50 Hz), and the controller tracks eye movement by identifying the center of the limbus in each acquired image. In response to the identification of the center of the limbus, during the simulated procedure, the controller moves the inner and outer ellipses so that the inner ellipse remains positioned over the limbus as defined by the physician, and the outer ellipse remains at an invariant distance from the inner ellipse even as the eye moves. Similarly, during the procedure, the controller can calculate the center or edge of each target region by adding an appropriate (x,y) displacement to the identified center of the limbus. Advantageously, this feedback process significantly improves the safety and effectiveness of the procedure.

[0032] Furthermore, as an additional safety measure, the controller may define an area in the aforementioned still image, which is referred to herein as the “forbidden zone.” The forbidden zone typically encompasses the pupil of the eye, along with the portion of the eye surrounding the pupil. The forbidden zone is defined within the camera’s field of view (FOV) and is static in that it does not adjust in response to detected eye movements. The controller can then prevent any therapeutic beam from hitting the forbidden zone. In addition, the controller can prevent beam-directing elements from being directed into the forbidden zone, even when the radiation source is idle. Thus, the retina of the eye is protected from potential (but unlikely) stray beams.

[0033] In some embodiments, the trabeculoplasty apparatus further includes a visible light source, and the controller is configured to flash the visible light source toward the eye, thereby keeping the visible light on for at least the duration of each image acquisition. Advantageously, the flash reduces the time required for image acquisition, and as a result, the position of the target region calculated in response to the image does not shift significantly before the aiming or therapeutic beam is emitted toward the target region. Furthermore, the flash can constrict the pupil of the eye, thus providing further protection to the retina from potential stray beams.

[0034] Typically, the light flashes at a sufficiently high frequency, and / or each pulse of light has a sufficiently long duration, so the flash goes unnoticed by the patient. Nevertheless, the total energy of the flashed light is low enough so that the light does not damage the retina.

[0035] Alternatively, the eye can be illuminated with near-infrared light to reduce the time required for image acquisition without causing discomfort to the patient. Furthermore, as an option, visible light may be flashed towards the eye so that visible light is turned on while and / or between image acquisitions.

[0036] Embodiments of the present invention further provide techniques for facilitating the positioning of a trabeculoplasty device at the correct distance (or "range") from the eye. Conventionally, this type of positioning is performed by directing two circular distance measuring beams from the device towards the eye and moving the device closer to or further away from the eye until the two beams overlap. However, as the inventors have observed, for several reasons, this technique can be difficult to use for positioning a trabeculoplasty device. For example, the sclera is covered by the conjunctiva, which can distort and reflect the distance measuring beams, making it impossible to discern that the beams overlap. Therefore, in embodiments of the present invention, the distance measuring beams are given different shapes such that the beams form a specific pattern only when the trabeculoplasty device is positioned at the correct distance from the eye. For example, the distance measuring beams are formed as orthogonal ellipses, so that the distance measuring beams form a cross over the eye only at the correct distance.

[0037] In some embodiments, to reduce scleral occlusion by the upper eyelid, the optical unit of the trabeculoplasty apparatus is mounted on a wedge so that the camera and radiation source are angled upward. The patient's line of sight is then directed downward towards the optical unit so that the upper part of the patient's sclera is exposed.

[0038] Although the description herein relates primarily to trabeculoplasty, the techniques described herein can also be applied to automated photocoagulation, iridotomy, capsule excision, lens removal, or other related ophthalmic surgeries. The radiation target may include the trabecular meshwork and / or other suitable parts of the eye, such as endothelial stem cells or Schlemm's canal cells of the eye. Embodiments of the present invention can be used to treat glaucoma, ocular hypertension (OHT), and other diseases.

[0039] (System description) First, refer to Figure 1, a schematic diagram of a system 20 including a trabeculoplasty apparatus 21 for performing trabeculoplasty according to some embodiments of the present invention. Further refer to Figure 2, a schematic diagram of the trabeculoplasty apparatus 21 according to some embodiments of the present invention.

[0040] The trabeculoplasty apparatus 21 includes an optical unit 30. The optical unit 30 comprises a radiation source 48 configured to irradiate the eye 25 of a patient 22 with both a targeting beam and a therapeutic beam as described herein. The optical unit 30 further includes one or more beam-directing elements, for example, one or more Garbo mirrors 50 (which may be collectively referred to as “Garbo scanners”) and / or a beam focuser 56. Before the emission of each beam 52 from the radiation source 48, or while the beam is being emitted, the controller 44 directs the beam-directing elements to a desired target area over the eye 25 so that the beam is directed towards the target area by the beam-directing elements. For example, the beam may be deflected by the Garbo mirrors 50 towards the beam focuser 56, and then the beam may be deflected through an aperture 58 on the front of the optical unit so that the beam impacts the target area. Each beam emitted by the radiation source may have an elliptical (e.g., circular), square, or any other suitable shape.

[0041] Typically, a radiation source consists of two lasers: one for emitting the targeting beam described herein, and the other for emitting the therapeutic beam described herein. As a purely illustrative example, the therapeutic laser may include an Ekspla® NL204-0.5K-SH laser (e.g., modified to include an attenuator, energy meter, and mechanical shutter), while the targeting laser may include a Laser Component® FP-D-635-1DI-CF laser. Typically, both the targeting beam and the therapeutic beam contain visible light.

[0042] As an alternative to or addition to the laser, the radiation source may include any other suitable emitter configured to emit radiation belonging to any suitable part of the electromagnetic spectrum, such as microwave radiation, infrared radiation, X-ray radiation, gamma radiation, or ultraviolet radiation.

[0043] In some embodiments, each beam 52 passes through a beam expander (not shown) before reaching the Garbo scanner, which expands and then recollimates the beam. In such embodiments, the optical unit 30 typically includes an F-theta lens 51 configured to focus each beam following beam orientation by the Garbo scanner.

[0044] In other embodiments, the focusing lens is positioned between the radiation source and the Garbo scanner. For example, the beam expander described above may include a focusing lens instead of a collimating lens, or the optical unit may include a focusing lens in addition to the beam expander. In such embodiments, each beam is focused by the focusing lens before being directed by the beam directing element, so that the F-theta lens 51 is not required.

[0045] The optical unit 30 further comprises a camera 54. Before and during the procedure, the camera 54 acquires multiple images of the patient's eye, typically at a relatively high frequency. The controller 44 processes these images and, in response, controls the radiation source 48 and beam directional elements, as described below with reference to Figures 3-4. As shown in Figure 2, the camera 54 may be positioned behind the beam focuser 56 so that the camera receives light through the beam focuser.

[0046] Typically, the optical unit 30 further includes an illumination source 60 which includes one or more light-emitting diodes (LEDs), such as a ring of LEDs surrounding the aperture 58. In such embodiments, the controller 44 can cause the illumination source 60 to intermittently flash light toward the eye, as will be further described below with reference to Figure 4. (For ease of explanation, the connection between the controller 44 and the illumination source 60 is not explicitly shown in Figure 2.)

[0047] The optical unit 30 is mounted on an XYZ stage 32, which is controlled by a control mechanism 36, such as a joystick. Using the control mechanism 36, a user of the system 20, such as an ophthalmologist or another physician, can position the optical unit appropriately before treating a patient's eye. In some embodiments, the XYZ stage 32 includes a locking element configured to prevent movement of the stage after it has been positioned.

[0048] In some embodiments, the XYZ stage 32 includes one or more motors, and a control mechanism 36 is connected to an interface circuit 46. When a user operates the control mechanism, the interface circuit 46 converts this activity into appropriate electronic signals and outputs these signals to a controller 44. In response to the signals, the controller controls the motors of the XYZ stage. In other embodiments, the XYZ stage 32 is controlled manually by operating the control mechanism.

[0049] Typically, before the radiation source emits a beam toward the eye, the user uses a control mechanism 36 to position the optical unit at a predetermined distance D from the eye. To facilitate this positioning, the optical unit may include multiple beam emitters 62 (e.g., each including a laser diode), which are configured to irradiate the eye with multiple distance measuring beams 64, for example, with an angle between beams of 30-100 degrees. As will be further explained below with reference to Figure 3, the distance measuring beams 64 are shaped to define different parts of a predefined composite pattern, and the predefined composite pattern is formed in the eye only when the optical unit is at a predetermined distance from the eye. Thus, in response to the observation of the composite pattern, the user can confirm that the optical unit is at the predetermined distance.

[0050] The system 20 further comprises a headrest 24 mounted on a horizontal surface 38 such as a tray or tabletop. The headrest 24 includes a forehead rest 26 and a chin rest 28. During the trabeculoplasty procedure, the patient 22 presses their forehead against the forehead rest 26 while resting their chin on the chin rest 28.

[0051] In some embodiments, the headrest 24 further comprises a restraint strap 27 configured to secure the patient's head from behind and thus keep the patient's head pressed against the headrest. The restraint strap 27 may include a single segment configured to extend from the headrest on one side of the head and secure to the headrest on the opposite side of the head, or two segments configured to extend from the headrest on opposing sides of the head and secure to each other behind the head. Optionally, the restraint strap may include a sensor configured to detect when the restraint strap is properly secured. For example, when the restraint strap is tightened, an electrical circuit is closed, and the sensor may detect a current flowing through the circuit and generate an output in response (e.g., by lighting an LED).

[0052] In some embodiments, the headrest 24 further includes one or more sensors, which may be located, for example, on the forehead rest or chin rest. Each of these sensors may be configured to produce an output indicating whether the patient's head is resting on the headrest, as needed. Examples of suitable sensors include capacitive sensors, resistive sensors, and piezoelectric sensors. Alternatively or additionally, the headrest may include one or more switches or force-sensitive resistors, such as Sparkfun® 9375.

[0053] In some embodiments, physical blocks are placed around the eyes to block radiation reflected by the eyes. For example, a hood may be placed on the chin rest and / or the patient's head. Alternatively or additionally, the hood may be coupled to the surface of the device 21.

[0054] In some embodiments, the apparatus 21 further includes a base unit 34 mounted on a horizontal plane 38, and the XYZ stage 32 is mounted on the base unit 34. In such embodiments, a controller 44 and interface circuitry 46 may be located within the base unit. In other embodiments, the XYZ stage is mounted directly on the horizontal plane 38.

[0055] Typically, as shown in Figure 1, while illuminating the patient's eye, the optical unit is angled diagonally upward toward the eye, and one eye gazes diagonally downward toward the optical unit; that is, the optical path 23 between the eye and the optical unit is oblique rather than horizontal. For example, the optical path 23 can be oriented at an angle θ between 5 and 20 degrees. Advantageously, this orientation reduces obstruction of the patient's eye by the patient's upper eyelid and associated anatomical structures. As an option, one or both eyelids can be retracted using a finger, microscope, or another tool for additional exposure of the eye.

[0056] In some embodiments, as shown in Figure 1, the oblique direction of the optical path is achieved by an optical unit mounted on a wedge 40 attached to an XYZ stage. In other words, the optical unit is mounted to the XYZ stage via the wedge 40.

[0057] Instead of using the wedge 40, or in addition to it, the oblique direction of the optical path can be achieved by tilting the patient's head backward. For example, the forehead rest 26 and / or chin rest 28 may include length-adjustable straps, and the patient's head may be tilted backward by adjusting the length of the straps. (For example, the forehead strap may be retractable.) To facilitate this adjustment, the length-adjustable straps may include warm-type drives, hook-and-loop fasteners, snaps, locking pins, knots, and / or any other suitable mechanism.

[0058] In other embodiments, the patient's head is tilted slightly forward, for example, by angling the headrest 24 (or at least the chin rest 28) toward the optical unit, resulting in the patient's head resting more firmly on the headrest.

[0059] The system 20 further comprises a monitor 42 configured to display an image of the eye acquired by a camera, as will be described in detail below with reference to Figure 3. The monitor 42 can be positioned at any suitable location, such as a horizontal plane 38 adjacent to the device 21. In some embodiments, the monitor 42 includes a touchscreen, through which the user enters commands into the system. Alternatively or additionally, the system 20 may include any other suitable input device, such as a keyboard or mouse, which can be used by the user.

[0060] In some embodiments, the monitor 42 is directly connected to the controller 44 via a wired or wireless communication interface. In other embodiments, the monitor 42 is connected to the controller 44 via an external processor, such as a processor belonging to a standard desktop computer.

[0061] It should be emphasized that the configuration shown in Figure 2 is provided as an example only. Apparatus 21 may include any suitable components, which may be further alternative or additional to the components shown in Figure 2. For example, the apparatus may include an additional light source, such as an LED, which the patient can gaze at during the procedure. Such a light source may be placed, for example, near the aperture 58 or next to the camera.

[0062] In some embodiments, at least some of the functions of the controller 44 described herein are implemented in hardware, for example, using one or more application-specific integrated circuits (ASICs) or field-programmable gate arrays (FPGAs). Alternatively or additionally, the controller 44 may perform at least some of the functions described herein by executing software and / or firmware code. For example, the controller 44 may comprise a central processing unit (CPU) and random access memory (RAM). Program code and / or data, including software programs, may be loaded into RAM for execution and processing by the CPU. Program code and / or data may be downloaded to the controller in electronic form, for example, over a network. Alternatively or additionally, program code and / or data may be provided and / or stored in a non-transient tangible medium such as magnetic, optical, or electronic memory. When such program code and / or data is provided to the controller, it generates a machine or dedicated computer configured to perform the tasks described herein.

[0063] In some embodiments, the controller includes a system-on-module (SOM) such as Varisite® DART-MX8M.

[0064] In some embodiments, the controller 44 is located outside the device 21. Alternatively or additionally, the controller can perform at least some of the functions described herein in cooperation with another external processor.

[0065] (Pre-treatment procedure) Here, we refer to Figure 3, which is a schematic diagram of a pretreatment procedure according to several embodiments of the present invention.

[0066] First, the procedure shown in Figure 3 has three steps, referred to as steps A through C in the figure. Figure 3 shows, for each of these steps, an image of the eye 25 acquired by camera 54 (Figure 2) and displayed on monitor 42 by controller 44 (Figure 2). Typically, a graphical user interface (GUI) 68 is further displayed alongside each image on monitor 42. The GUI 68 may include text boxes containing relevant alphanumeric data and / or instructions to the user, buttons for confirming or rejecting a particular treatment plan, and / or other relevant widgets.

[0067] In step A, the user positions the optical unit 30 (Figure 2) so that the center of the eye is approximately in the center of the camera's FOV. The user also positions the optical unit at the correct distance from the eye so that the treatment beam has an appropriate spot size for the eye. As described above with reference to Figure 2, this positioning is typically facilitated by distance measuring beams 64. They are shaped to define different parts of a predefined composite pattern 66, so that the pattern 66 is formed on the eye only when the optical unit is at the correct distance. Typically, the user forms the composite pattern on the sclera of the eye near the limbus. (Typically, while the optical unit is being positioned, the controller displays a live sequence of images of the patient's eye.)

[0068] For example, as shown in Figure 3, the distance measuring beam can be shaped to define two vertical shapes, such as two vertical ellipses, rectangles, or lines, which form a cross to the eye only when the optical unit is at the correct distance. Alternatively, the distance measuring beam can be shaped to define two arcs or semicircles forming a circle, or two triangles or arrowheads forming a rhombus or X shape. Any suitable optical element, such as a diffractive optical element (DOE), hologram, or axicon, can be used to facilitate the generation of these patterns.

[0069] In other embodiments, only a single distance-measuring beam is emitted, and a computer-generated pattern is superimposed on the image of the eye. When the optical unit is at the correct distance, the distance-measuring beam and the computer-generated pattern overlap or form a composite pattern 66.

[0070] In response to observing the composite pattern 66, the user indicates to the controller that the optical unit is at the correct distance from the eye. For example, the user can click the appropriate button on the GUI 68. In response to this input, the controller proceeds to step B of the pretreatment procedure.

[0071] In step B, the controller displays a still image 71 of the eye. Subsequently, based on user input, the controller identifies elliptical (e.g., circular or nearly circular) portions of the eye, such as the limbus 69 of the eye. For example, the controller can identify an eye portion in response to the user superimposing an elliptical marker 78 over the eye portion. Then, as will be further described below, the position of the elliptical marker 78 can be used to calculate the position of each target area of ​​the treatment beam.

[0072] For example, the controller can display both an elliptical marker 78 and a rectangle 80 that circumscribes (or "bounds") the elliptical marker on a still image. The user can then adjust the rectangle 80 by, for example, dragging its sides or corners using a mouse or touchscreen. (In some embodiments, the system allows the user to switch between rough and fine adjustments of the rectangle.) In response to user adjustments to the rectangle, the controller can adjust the elliptical marker 78 so that the elliptical marker remains circumscribed by the rectangle until it is superimposed on the user-defined limbus (or another part of the eye). The user can then indicate to the controller (for example, via GUI 68) that the elliptical marker is superimposed on the user-defined limbus.

[0073] In some embodiments, the controller overlaps two horizontal lines touching the top and bottom ends of the elliptical marker 78, respectively, and two vertical lines touching the left and right ends of the elliptical marker 78, respectively, without necessarily intersecting the lines and thus defining a rectangle. In such embodiments, the user can adjust the elliptical marker 78 by dragging the lines.

[0074] Typically, before allowing the user to adjust the elliptical marker 78, the controller identifies the limbus in a still image using an edge detection algorithm or other appropriate image processing technique, and then displays the elliptical marker 78 on the limbus. (Note that the controller can approximate the shape of the limbus with any suitable shape, such as an ellipse aligned with the vertical and horizontal axes, or rotated at any suitable angle.) Advantageously, initializing the placement of the elliptical marker 78 in this way reduces the time required for marker adjustment. (Since the limbus is not generally a clearly defined feature, the position of the limbus identified by the user is usually slightly different from the position initially identified by the controller. Therefore, the user can adjust the marker as described herein.)

[0075] Instead of adjusting the rectangle, or in addition to doing so, the user can directly adjust the elliptical marker 78 by inputting relevant parameters. For example, for an elliptical (e.g., circular) marker, the user can input the coordinates of the center of the elliptical marker and one or two diameters of the marker. Alternatively or additionally, the user can adjust the elliptical marker by adjusting the input to the limbal identification algorithm performed by the controller (such as a threshold for edge detection). Yet another option is for the user to directly manipulate the elliptical marker 78.

[0076] In an alternative embodiment, the elliptical marker 78 is not shown at all. In such an embodiment, the user can indicate the location of the limbus by dragging a rectangle or line that would have bounded the marker if it had been shown. As yet another alternative, for greater accuracy, a non-elliptical marker having a different shape that more precisely matches the shape of the limbus 69 can be used instead of the elliptical marker 78.

[0077] Typically, before performing the pretreatment procedure shown in Figure 3, the user specifies the location of each of the multiple target areas relative to the eye, identified in step B (using GUI68 or other appropriate input interface). Alternatively, these parameters can be predefined before the user uses the system.

[0078] For example, the user can specify an elliptical path of target regions adjacent to the limbus by specifying the number of target regions and the distance from (or from the center of) the center or edge of each target region should be located. Alternatively, the user can specify a path of one or more arcs by specifying, in addition to the aforementioned parameters, (i) the angular span of each arc and (ii) the position of each arc. (For example, the user can specify a 180-degree arc around the lower or upper half of the limbus, or a 90-degree arc at the apex and apex, respectively.) Based on this input and the limbus position specified by the user, the controller typically calculates the position of each target region relative to the center of the limbus identified by the controller. (In some embodiments, the controller calculates the positions of the ellipse or arcs specified by the user, but does not calculate the specific positions of the target regions on the ellipse or arcs until after step C, described below, has been performed.)

[0079] As a purely illustrative example, the user can set the center or edge of each target region to a different angle θ relative to the center of the limbus. iThen, the user can specify that the distance from the limbus marked by the user is d1. Next, during step B, the user can adjust the elliptical marker 78 so that the center of the marker is at (x0+Δx, y0+Δy), where (x0, y0) is the center of the limbus identified by the controller. In such a case, assuming that the elliptical marker 78 is a circle of radius R, the controller can set the offset from the center of the limbus of the center or edge of each target region to (Δx+(R+d1)cos(θ i ),Δy+(R+d1)sin(θ i It can be calculated as follows: (d1 can be zero, i.e., the center or edge of each target region may coincide with the limbus marked by the user, and it should be noted that the center or edge of each treatment beam will collide with the limbus marked by the user. Subsequently, during the procedure, as further described below with reference to Figure 4, the controller can track the center of the limbus and, for each target region, calculate the position of the target region by adding this offset to the center position.

[0080] Typically, in step B, the controller also identifies, based on a still image, a static area 76 within the camera's field of view (FOV) that includes the pupil 74 (also referred to herein as the “forbidden zone”), along with a “buffer” that typically includes a substantial portion of the cornea 72 of the eye surrounding the pupil 74. Typically, the dimensions of the buffer are set based on the expected maximum movement of the eye.

[0081] In some embodiments, the static region 76 is identified based on the position of the limbus, either automatically identified by the controller or marked by the user. For example, the controller may identify the static region 76 as a set of all points within the FOV located inside the limbus beyond a predefined distance from the limbus. Alternatively, for example, the controller may identify a point at the center of the limbus or the center of the pupil, and then identify the central region 76 at this center point. In such embodiments, the static region 76 may have any suitable shape, such as an ellipse or a rectangle, and may have any suitable size. The importance of the static region 76 is explained below with reference to Figure 4. (Note that the static region 76 is not necessarily displayed on the monitor 42.)

[0082] Following step B, the controller proceeds to step C, where the trabeculoplasty procedure is simulated. In response to the simulation display, the user can provide confirmation input to the controller by clicking the appropriate button on GUI68 (e.g., the "Start" button). This input confirms to the controller that the procedure should proceed.

[0083] More specifically, in step C, the controller displays a live sequence of images of the eye (i.e., live video) and, while displaying the sequence of images, illuminates the eye with one or more targeting beams 84 visible in the image. Typically, the targeting beams are red. For example, each targeting beam may have a wavelength of 620–650 nm. In some embodiments, the color of the targeting beams differs from the color of the treatment beams. For example, the targeting beams may be red, while the treatment beams may be green, for example, with a wavelength of 515–545 nm (e.g., 532 nm).

[0084] While the aiming beam is shining into the eye, the controller controls the beam directing elements so that, if a treatment beam is emitted, it will collide with a calculated target area. Thus, the center of each aiming beam may sequentially coincide with the center of each target area. Alternatively, if an F-theta lens 51 (Figure 2) is used and the color of the aiming beam differs from the color of the treatment beam, chromatic aberration introduced by the F-theta lens may cause the aiming beam to deviate slightly from the target area. Nevertheless, even in this case, the aiming beam will usually collide with at least a portion of each target area.

[0085] In some embodiments, the controller sweeps a single aiming beam along the eye so that the aiming beam collides with at least a portion of each target area. In other embodiments, the controller emits multiple aiming beams, each aiming beam collides with at least a portion of each different target area.

[0086] Typically, during the simulation, the controller superimposes the elliptical marker 78 onto the eye portion identified in step B. To compensate for eye movement, the controller typically identifies the center of the limbus in each image and positions the elliptical marker 78 appropriately offset from the limbus. For example, if the final position of the center of the elliptical marker 78 in the still image (step B) is (x0+Δx, y0+Δy), the controller can position the elliptical marker 78 in each live image at an offset of (Δx, Δy) from the center of the limbus.

[0087] Instead of superimposing or adding the elliptical markers 78, the controller can superimpose another marker 82 on each image, either passing through each target region (e.g., through the center) or near each target region. The position of the marker 82 can be adjusted in response to eye movements by maintaining the marker 82 at an appropriate displacement from the elliptical marker 78. For example, if the center of each target region should be at a distance d1 from the limbus marked by the user, the marker 82 may be kept at a distance d1 from the elliptical marker 78. In some embodiments, the marker 82 is a different color from the elliptical marker 78.

[0088] Typically, during the execution of a simulation, the controller verifies that each of the targeting beams is properly directed by the beam-directing element. For example, the controller can process feedback signals from the encoder of the Garbo mirror 50. Alternatively or additionally, the controller can verify the position of each targeting beam relative to the elliptical marker 78, marker 82 and / or other appropriate markers superimposed on each image by processing the image. For example, the controller can verify that each targeting beam (e.g., the center of each targeting beam) coincides with marker 82 and / or that the end of each targeting beam touches the elliptical marker 78. (In the context of this application, including the claims, “end” of the beam means knife-edge measurement, 1 / e 2 It can be defined in terms of width measurement, full width at half maximum measurement, or other appropriate measurement.) As another example, the controller verifies that the center or end of each aiming beam is positioned at an appropriate distance from the elliptical marker 78. In response to the confirmation of the aiming beam position, the controller may proceed with the trabeculoplasty procedure, provided that the user provides the aforementioned confirmation input.

[0089] In some embodiments, the process is terminated if the user does not confirm the simulation. In other embodiments, the user can adjust the path followed by the aiming beam (e.g., via GUI68). This adjustment may be performed by returning to step B and adjusting the elliptical markers 78 and / or by adjusting the distance from the elliptical markers 78 to which each target area should be placed. In such embodiments, the simulation may be repeated for each new path defined by the user until the user confirms the path.

[0090] (Procedure) In response to receiving the aforementioned confirmation input from the user, the controller treats the eye by irradiating the target area with each treatment beam. The peak power of the treatment beam is much higher than that of the aiming beam. Furthermore, typically, the wavelength of the treatment beam is more suitable for treating the trabecular meshwork of the eye compared to the wavelength of the aiming beam.

[0091] More specifically, during the procedure, the controller continuously sweeps the aiming beam across the target region or continuously emits each aiming beam into the target region while acquiring an image of the eye. As further explained below with reference to Figure 4, the controller confirms the position of the aiming beam in each image and, in response, emits a therapeutic beam into the eye. For example, the controller can emit a therapeutic beam towards the target region where the aiming beam has struck, or towards the next target region.

[0092] Typically, the controller directs each treatment beam to the eye outside a static area 76 (Figure 3), also referred to herein as the “forbidden zone.” (As described above, the static area 76 is static in that the area is defined with respect to the camera’s FOV and therefore does not move with the eye.) As an additional precaution, the controller may prohibit the beam-directing element from directing (i.e., “passing through”) the static area 76, even when none of the treatment beams are being emitted. (Typically, the controller also applies these precautions when emitting the aiming beam during the pretreatment procedure.)

[0093] Typically, while acquiring each image during the procedure, the controller flashes visible light (e.g., white, red, or green light) from the illumination source 60 (Figure 2). Thanks to this flash, the required exposure time for the camera can be reduced by, for example, three times or more. Thus, the required exposure time can be reduced from, for example, 9 milliseconds to 3 milliseconds. Each flash may start before image acquisition or end after acquisition. Typically, the peak average intensity over the duration of each flash is 0.003–3 mW / cm².2 This is generally strong enough to shorten the required camera exposure time and constrict the pupil of the eye without harming the patient.

[0094] Typically, the light flashes at a frequency high enough that the patient does not notice the flash and perceives it as a steady illumination. For example, the light may flash at a frequency of at least 60 Hz, such as at least 100 Hz. (In such embodiments, the duration of each flash (or "pulse") is typically less than 3 milliseconds, e.g., less than 2 milliseconds or 1 millisecond.) Because the flash frequency is higher than the frame rate (i.e., how often images are acquired), some flashes may occur during image acquisition. For example, the flash frequency may be an integer multiple of the frequency at which images are acquired so that the flash is synchronized with the image acquisition. As a purely illustrative example, if the frame rate is 60 Hz, the flash frequency may be 120 Hz or 180 Hz.

[0095] Alternatively, the light may flash at a lower frequency, but the duration of each flash may be increased so that a steady illumination is perceived. For example, if a patient perceives flickering with a flash frequency of 100 Hz and a duty cycle of 20%, the duty cycle can be increased to 40% by increasing the pulse width without changing the frequency.

[0096] In some embodiments, the illumination source 60 is configured to emit near-infrared light. In such embodiments, near-infrared light can be continuously emitted during the procedure, or at least while an image is being acquired, in order to reduce the required camera exposure time without disturbing the patient. Alternatively, the illumination source 60 can also flash visible light towards the eye during and / or between image acquisitions to further reduce the required exposure time and / or constrict the pupil.

[0097] With reference to Figure 4, which is a schematic diagram of an exemplary algorithm 86 for performing an automated trabeculoplasty procedure according to some embodiments of the present invention, some further details relating to the trabeculoplasty procedure are provided.

[0098] To initiate the procedure after user approval of the simulated procedure, the controller flashes light towards the eye in imaging and localization step 88, using a camera to acquire an image of the eye during the flash and locating the position of the center of the limbus in the acquired image. Subsequently, in target calculation step 90, the controller calculates the position of the next target area by adding an appropriate (x,y) offset to the position of the center of the limbus. After confirming this position, the target area is illuminated, as will be further described below. Next, the controller acquires another image, calculates the position of the next target area, confirms the position, and illuminates the target. In this way, the controller repeatedly illuminates the target area.

[0099] More specifically, for each calculated target region, the controller checks in the first target check step 92 whether the target region is (partially) in the forbidden zone, where the forbidden zone is, recalled, a static region within the camera's FOV. (To perform this check, the controller does not necessarily have to explicitly calculate the boundaries of the target region; for example, the controller may check whether a point at the center of the target region is farther from the boundary of the forbidden zone than a predefined distance—equal to or slightly greater than the radius of the aiming or therapeutic beam.) If not, the controller performs the second target check step 94, and assuming there is a previous target region in front of the target region, the controller checks whether the target region is at an acceptable distance from the previous target region. For example, the controller may check whether the distance between the target region and the previous target region is less than a predefined threshold, which indicates that the eye is relatively stationary. If the target region is not at an acceptable distance from the previous target region, or if the target region is in the forbidden zone, the controller returns to the imaging and localization step 88.

[0100] If the calculated target region passes both the first target check step 92 and the second target check step 94, the controller directs the beam-directing element towards the target region in the aiming step 96. The controller then directs the aiming beam towards the beam-directing element in the aiming beam emission step 98, thereby directing the aiming beam towards the target region. Alternatively, a single aiming beam may be emitted continuously, eliminating the need to perform the aiming beam emission step 98.

[0101] Next, the controller performs the imaging and localization step 88. Then, in the limbal center check step 100, the controller checks whether the center of the limbus has moved by more than a predefined threshold (relative to the most recently acquired image). If yes, the controller returns to the target calculation step 90 and recalculates the position of the target region relative to the center of the limbus. Otherwise, the controller identifies the aiming beam in the image in the aiming beam identification step 102.

[0102] Following the identification of the targeting beam, the controller checks in a first targeting beam check step 106 whether the targeting beam is in a restricted zone. If the targeting beam is in a restricted zone (indicating rapid eye movement or system failure), the controller terminates the procedure. Otherwise, in a second targeting beam check step 108, the controller checks whether the distance between the targeting beam and the calculated target area is within a predefined threshold. If it is not within the threshold, the controller returns to the target calculation step 90. If it is within the threshold, the controller emits a therapeutic beam in a therapeutic beam emission step 110, and the therapeutic beam collides with the target area.

[0103] Typically, in addition to identifying and confirming the position of the aiming beam, the controller checks each image for any obstructions that may be interfering with the target area, such as eyelids, eyelashes, fingers, growths (e.g., pterygium), blood vessels, or microscopic structures. If an obstruction is identified, the target area can be shifted to avoid the obstruction, or the target area can be completely skipped, or the procedure can be terminated.

[0104] Generally, obstacles can be identified using any appropriate image processing technique, combined with user input as options. For example, prior to a procedure, the user can select one or more parts of an eye (e.g., by referring to a still image) that constitute a potential obstacle. The controller can then identify the selected parts of the eye using template matching, end detection, or other appropriate techniques (e.g., including the identification of changes between consecutive images). Such techniques can also be used to identify other static or dynamic obstacles that the user may not have previously identified. (Note that the definition of “obstacle” may vary depending on the application. For example, a specific blood vessel may constitute an obstacle, or it may be desirable to irradiate a blood vessel.)

[0105] Following the treatment beam emission step 110, the controller checks in the final check step 112 whether all target regions have been processed. If yes, the controller terminates the procedure. Otherwise, the controller returns to the target calculation step 90.

[0106] Advantageously, the time between acquiring each image and emitting the therapeutic beam is typically less than 15 milliseconds, for example, less than 10 milliseconds. In some embodiments, this delay is further reduced by emitting the therapeutic beam between the aiming step 96 and the aiming beam emission step 98 (or, if a single aiming beam is emitted continuously, between the aiming step 96 and the imaging and localization step 88) rather than after the second aiming beam check step 108. (In such embodiments, the aiming beam is used to retrospectively confirm that the therapeutic beam was emitted correctly.)

[0107] In some embodiments, a separate routine performed by the controller monitors the time elapsed since each image acquisition. If this time exceeds a predefined threshold (such as a threshold of 10–15 milliseconds), the therapeutic beam is not emitted until the next image is acquired and the target position is recalculated.

[0108] Those skilled in the art will understand that the present invention is not limited to those specifically shown and described herein. Rather, the scope of the invention includes both combinations and subcombinations of the various features described above, as well as variations and modifications thereof that are not in the prior art and would be recalled by those skilled in the art upon reading the foregoing description.

Claims

1. A radiation source configured to emit a therapeutic beam of radiation; A camera configured to acquire images of the eye; and Controller and; A system having, The aforementioned controller is: Based on the image of the eye, a static region of the camera's field of view, including the pupil of the eye, is identified. and The steps include: calculating the next location in the target region; The steps include: determining whether one of the next target regions is within the static region based on the calculated position; and If one of the following target regions is not located within the static region, the radiation source is irradiated with the following target region; The system is configured to repeat the process, irradiating multiple target areas of the eye with the therapeutic beam from the radiation source. A system characterized by the following features.

2. The system further comprises one or more beam-directing elements configured to direct the therapeutic beam toward the target region. The system according to claim 1, further characterized in that the controller is configured to prevent the beam directing element from being directed towards the static area even when the therapeutic beam is not being emitted.

3. The system according to claim 1, characterized in that the step of checking whether one of the next target regions lies within the static region includes the step of checking whether the center of one of the next target regions is further than a predetermined distance from the boundary of the static region.

4. The system according to claim 1, characterized in that the static region includes a portion of the cornea of ​​the eye surrounding the pupil.

5. The system according to any one of claims 1 to 4, characterized in that the controller is configured to identify the static region based on the position of the limbus in the image.

6. The system according to claim 5, further comprising the step of receiving a limbal positioning input from a user indicating the position of the limbus.

7. The system according to claim 5, further characterized in that the controller is configured to identify the position of the limbus.

8. The system according to claim 5, characterized in that the controller is configured to identify the static region as a set of all points in the field of view of the camera that are located inside the limbus beyond a predetermined distance from the limbus.

9. The system according to claim 5, characterized in that the controller is configured to identify the static region by placing the center of the static region at the center of the limbus or the center of the pupil.

10. The system according to any one of claims 1 to 9, further comprising an optical unit including the radiation source, wherein the controller is configured to cause the radiation source to irradiate the target area while the optical unit is directed diagonally upward toward the eye and the eye is looking diagonally downward toward the optical unit.

11. The system according to claim 10, further comprising a wedge, wherein the optical unit is mounted on the wedge and directed diagonally upward toward the eye.

12. wedge and; An optical unit, which is attached to the wedge, faces diagonally upward, and has a radiation source; and A controller configured to treat a patient's eye by causing the radiation source to irradiate one or more therapeutic beams onto one or more target areas of the eye while the eye is looking diagonally downward toward the optical unit; A system characterized by having the following features.

13. The system according to claim 12, wherein the optical unit further comprises a camera configured to acquire an image of the eye.

14. The system according to claim 13, characterized in that the controller is configured to process the image in order to identify one or more target regions.

15. The system according to claim 14, characterized in that the controller is configured to identify the limbus of the eye and to select one or more target regions based on the identified limbus.

16. The system according to any one of claims 12 to 15, further comprising a motion stage, wherein the wedge is mounted on the motion stage.

17. The system according to any one of claims 12 to 16, characterized in that the wedge is configured to orient the optical unit upward by an angle between 5 and 20 degrees.

18. The system according to any one of claims 12 to 17, further comprising a forehead rest and a chin rest configured to fix the patient's head in an oblique orientation relative to the optical unit.

Images