Direct selective laser trabeculoplasty

Abstract

To provide ophthalmic devices and methods for the treatment of glaucoma, ocular hypertension (QHT), and other diseases.SOLUTION: A system (20) includes a radiation source (48) and a controller (44), configured to display a live sequence of images of an eye (25) of a patient (22), while displaying the sequence of images, cause the radiation source to irradiate the eye with one or more aiming beams (84), which are visible in the images, subsequently to causing the radiation source to irradiate the eye with the aiming beams, receive a confirmation input from a user, and in response to receiving the confirmation input, treat the eye by causing the radiation source to irradiate respective target regions of the eye with a plurality of treatment beams. Other embodiments are also described.SELECTED DRAWING: Figure 1

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, entitled "Direct Selective Laser Trabeculoplasty Process (DSLT) and Safety," filed July 2, 2018, (ii) U.S. Provisional Patent Application No. 62 / 739,238, entitled "Eye Tracking Flash Illumination," filed September 30, 2018, and (iii) U.S. Provisional Patent Application No. 62 / 748,461, entitled "Cross-Ranging Beam," filed October 21, 2018. The respective disclosures of each of these references are incorporated herein by reference. [Background technology]

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

[0004] Geffen, Noa, et al., "Transscleral Selective Laser Trabeculoplasty Without a Keratoscopic Lens," Journal of Glaucoma 26.3 (2017):201-207, describes a study investigating the results of selective laser trabeculoplasty (SLT) performed directly on the sclera without a keratoscopic lens.

[0005] U.S. Patent Application Publication No. 2015 / 0366706 to Belkin, the disclosure of which is incorporated herein by reference, describes an apparatus including a probe and a processor. The probe is configured to be positioned adjacent to a patient's eye and 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 control the probe to irradiate the selected target regions with the 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 a Keratoscopic Lens," Journal of Glaucoma 26.3 (2017): 201-207 Summary of the Invention

[0008] According to some embodiments of the present invention, there is provided a system 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, cause the radiation source to project one or more aiming beams onto the eye that are visible in the images. The controller is further configured to, after causing the radiation source to project the aiming beam onto the eye, receive a confirmation input from a user; and, in response to receiving the confirmation input, treat the eye by causing the radiation source to project multiple treatment beams onto respective target areas of the eye.

[0009] In some embodiments, the device further comprises a focusing lens and one or more beam directing elements, wherein the controller is configured to cause the radiation source to irradiate the treatment beam onto the eye by emitting the treatment beam through the focusing lens and towards the beam directing elements, whereby the beam is focused by the focusing lens before being directed towards the respective target region by the beam directing elements.

[0010] In some embodiments, the aiming beam impinges on at least a portion of each target area. In some embodiments, the controller is further configured to overlay, on each image, a marker passing through each target area. In some embodiments, the marker is oval. In some embodiments, at least a portion of each target area is located within 1 mm of the limbus.

[0011] In some embodiments, the controller is further configured to: overlay a marker on each image and, before treating the eye, confirm the position of each aiming beam relative to the marker by processing the image, wherein the controller is configured to treat the eye in response to confirming the position of the aiming beam. In some embodiments, the controller is configured to verify the position of the aiming beam by verifying that the aiming beam overlaps the marker.

[0012] In some embodiments, the controller is configured to verify the position of the aiming beam by verifying 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 strikes a respective portion of the eye over which the marker is superimposed. In some embodiments, the marker is oval.

[0013] In some embodiments, the controller is further configured to: display still images of the eye before displaying the live images; identify an oval portion of the eye in the still images based on input from the user; and in response to identifying the oval portion of the eye, superimpose an oval marker over the oval portion of the eye in each image.

[0014] In some embodiments, following identification of the elliptical portion of the eye, the controller is configured to superimpose an elliptical marker over the elliptical portion of the eye by: determining a displacement from the center of the limbus of the eye to the center of the elliptical portion of the still image; and for each image of the image: identifying the center of the limbus in the image; and superimposing an elliptical marker on the image such that the center of the elliptical marker is at the determined displacement from the center of the limbus.

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

[0016] In some embodiments, the system further comprises a camera configured to acquire the image and, before acquiring the image, acquire a still image of the eye, wherein the controller is further configured to: identify, based on the still image of the eye, a static region within the field of view of the camera that includes a pupil 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 device further comprises one or more beam-directing elements, wherein the controller is configured to treat the eye by sequentially directing the beam-directing elements to target regions and emitting a treatment beam to the beam-directing elements, wherein the controller is further configured to prohibit the beam-directing elements from being directed at the static region even while a treatment beam is not being emitted. In some embodiments, the controller is configured to identify the static region by receiving limbus location input from a user indicating the location of the limbus within the static image; and identifying the static region based on the location of the 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 multiple second images of the eye while treating the eye, and wherein the controller is configured to treat the eye by iteratively: confirming the position of each second aiming beam in the second image; and emitting a respective one of the treatment beams toward the eye in response to the confirmation.

[0019] In some embodiments, the controller is configured to verify the location by verifying that the distance between the second aiming beam and each one of the target areas is less than a predetermined threshold. In some embodiments, the controller is configured to emit a respective one of the treatment beams toward a respective one of the target regions. In some embodiments, further comprising an illumination source, wherein the controller is further configured to cause the illumination source to intermittently flash visible light toward the eye to illuminate the eye during at least the acquisition of each second image.

[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 It is between. In some embodiments, the controller is configured to cause the illumination source to flash light 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 to cause the illumination source to illuminate the eye with near-infrared light at least during acquisition of each second image.

[0021] In some embodiments, the controller is further configured to cause the illumination source to intermittently flash visible light toward the eye while the eye is being treated. In some embodiments, the optical unit further includes a radiation source and a plurality of beam emitters, wherein the controller is further configured to cause the beam emitters to emit a plurality of distance measurement beams toward the eye before causing the radiation source to emit the aiming beam toward the eye, the distance measurement beams being shaped to define different respective portions of a predefined composite pattern, such that the predefined composite pattern is formed on the eye only when the optical unit is at a predetermined distance from the eye.

[0022] In some embodiments, the distance measuring beam is shaped to define two perpendicular shapes, and the predefined composite pattern comprises a cross. In some embodiments, the device further comprises an optical unit including a radiation source, and the controller is configured to cause the radiation source to irradiate the target area while the optical unit is aimed diagonally upward toward the eye and the eye gazes diagonally downward toward the optical unit. In some embodiments, the optical unit further comprises a wedge, and is attached to the wedge so that the optical unit is oriented obliquely upward toward the eye.

[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 obliquely upward, the optical unit including a radiation source; and a controller configured to treat a patient's eye by causing the radiation source to irradiate multiple treatment beams onto respective target areas of the eye while the eye gazes obliquely downward towards the optical unit.

[0024] According to some embodiments of the present invention, there is provided a method comprising the steps of: displaying a live sequence of images of a patient's eye; illuminating the eye with one or more aiming beams visible in the images while displaying the sequence of images; receiving a confirmation input from a user following the step of illuminating the aiming beams with the eye; and treating the eye by illuminating respective target areas of the eye with multiple treatment beams in response to receiving the confirmation input. [Brief explanation of the drawings]

[0025] The present invention will be more fully understood from the following detailed description of embodiments thereof, which refers to the drawings in which: [Figure 1] 1 is a schematic diagram of a system for performing trabeculoplasty, according to some embodiments of the present invention. [Figure 2] 1 is a schematic illustration of a trabeculoplasty device, according to some embodiments of the present invention. [Figure 3] 1 is a schematic diagram of a pre-treatment procedure, according to some embodiments of the present invention; and [Figure 4] FIG. 1 is a schematic diagram of an exemplary algorithm for performing an automated trabeculoplasty procedure, according to some embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] (overview)

[0006] Embodiments of the present invention provide an automated trabeculoplasty device configured to safely and efficiently perform a trabeculoplasty procedure on an eye. The trabeculoplasty device includes a controller and an optical unit including 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 a beam of radiation emitted by the radiation source to an appropriate location on the eye. The emitted radiation beam includes both a treatment beam that irradiates the trabecular meshwork of the eye and an aiming beam that is used to help aim the treatment beam.

[0027] Typically, prior to a procedure, the controller displays a live video of the eye with two ellipses superimposed on it: an inner ellipse representing the eye's limbus, and an outer ellipse offset a small distance from the inner ellipse and passing through or near each target area to be irradiated by the treatment beam. The controller also typically simulates the procedure by sweeping the aiming beam over the outer ellipse so that the aiming beam impinges on 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, i.e., the path along which the target areas lie. After the physician confirms the target path along the eye, the controller causes the radiation source to emit the treatment beam toward the target areas.

[0028] Note that because each beam of radiation generally strikes the eye with a non-minuscule spot size, this application generally describes each beam as striking a "region" of the eye, the area of ​​which is a function of the spot size, rather than a "point" on the eye. Thus, for example, this application relates to a "target region" rather than a "target point." Nevertheless, in the context of this application, including the claims, references to calculating the position of a target region can implicitly refer to calculating the position of the region by calculating the position of a single point within the region, such as the center or edge of the region toward which the center or edge (respectively) of the beam is directed. (Subsequently, even if the center or edge of the beam is slightly offset from the calculated point, this application, including the claims, can still consider the beam to have struck the calculated target region.)

[0029] Typically, before simulating the above procedure, the controller acquires a still image of the eye and identifies the limbus within the still image. The controller then overlays the inner ellipse described above on the limbus. The controller then allows the physician to change the position and / or shape of the inner ellipse so that it marks the limbus as defined by the physician. (Because the limbus is generally not well-defined, the location of the limbus for each physician may differ slightly from the location automatically identified by the controller.) For example, the controller may enclose an inner ellipse in 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 treatment beam strikes the eye at or near the limbus, which can be identified by the user as described above or automatically by the controller. Thus, 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 can be located within 1 mm (e.g., within 400 microns) of the limbus. As a specific example of the above, the center of each target area can be located within 1 mm (e.g., within 400 microns) of the limbus, thereby allowing the center of each treatment beam to strike the eye within 1 mm (e.g., within 400 microns) of the limbus.

[0031] In both the simulated and actual procedures, a camera acquires images of the eye at a relatively high frequency (e.g., greater than 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 identifying the limbus center, during the simulated procedure, the controller shifts the inner and outer ellipses so that the inner ellipse remains positioned over the physician-defined limbus and the outer ellipse remains a consistent 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 the appropriate (x,y) offset to the identified limbus center. Advantageously, this feedback process significantly improves the safety and effectiveness of the procedure.

[0032] Additionally, as an additional safety measure, the controller can define an area in the aforementioned still image, referred to herein as a "prohibited zone." The prohibited zone typically encompasses the eye's pupil, along with the portion of the eye surrounding the pupil. The prohibited zone is static in that it is defined in the camera's field of view (FOV) and does not adjust in response to detected eye movement. The controller can then prevent any of the treatment beams from striking the prohibited zone. Furthermore, the controller can prevent the beam-directing element from being aimed at the prohibited zone even while the radiation source is dormant. Thus, the eye's retina is protected from potential (albeit unlikely) stray beams.

[0033] In some embodiments, the trabeculoplasty device further includes a visible light source, and the controller is configured to cause the visible light source to flash visible light toward the eye, thereby turning the visible light on at least while each image is being acquired. Advantageously, the flash reduces the time required to acquire an image, such that the position of the target area calculated in response to the image does not move significantly before the aiming or treatment beam is emitted at the target area. Additionally, the flash can constrict the pupil of the eye, thus further protecting the retina from potential stray beams.

[0034] Typically, the light flashes at a high enough frequency and / or each pulse of light has a long enough duration that the flash goes unnoticed by the patient, yet the total energy of the flashed light is low enough 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. Additionally, optionally, visible light can be flashed onto the eye so that it is on while images are being acquired and / or between image acquisitions.

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

[0037] In some embodiments, to reduce occlusion of the sclera by the upper eyelid, the optical unit of the trabeculoplasty device is mounted on a wedge with the camera and radiation source pointing diagonally upward, and the patient's gaze is then directed diagonally downward toward the optical unit so that the top of the patient's sclera is exposed.

[0038] Although the description herein primarily relates to trabeculoplasty, the techniques described herein may also be applied to autophotocoagulation, iridotomy, capsulectomy, lens removal, or other related ophthalmic procedures. Radiation targets 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 may be used to treat glaucoma, ocular hypertension (OHT), and other diseases.

[0039] (System Description) Reference is initially made to Figure 1, which is a schematic illustration of a system 20 including a trabeculoplasty device 21 for performing trabeculoplasty, according to some embodiments of the present invention. Reference is further made to Figure 2, which is a schematic illustration of a trabeculoplasty device 21, according to some embodiments of the present invention.

[0040] The trabeculoplasty device 21 includes an optical unit 30. The optical unit 30 comprises a radiation source 48 configured to irradiate the eye 25 of the patient 22 with both the aiming beam and the treatment beam described herein. The optical unit 30 further includes one or more beam-directing elements, including, for example, one or more galvo mirrors 50 (which may be collectively referred to as a "galvo scanner") and / or a beam concentrator 56. Prior to or during emission of each beam 52 from the radiation source 48, the controller 44 directs the beam-directing element toward a desired target area on the eye 25 so that the beam is directed by the beam-directing element to the target area. For example, the beam may be deflected by the galvo mirror 50 toward the beam concentrator 56, and then the beam may be deflected through an aperture 58 in the front face of the optical unit so that the beam impinges on 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, the radiation source consists of two lasers: one for emitting the aiming beam described herein and the other for emitting the treatment beam described herein. As a purely illustrative example, the treatment laser may include an Ekspla® NL204-0.5K-SH laser (e.g., modified to include an attenuator, energy meter, and mechanical shutter), while the aiming laser may include a Laser Components® FP-D-635-1DI-CF laser. Typically, both the aiming beam and the treatment beam include visible light.

[0042] Alternatively or in addition to a laser, the radiation source may include any other suitable emitter configured to emit radiation belonging to any suitable part of the electromagnetic spectrum, including, for example, 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 galvo scanner, which expands and then recollimates the beam. In such embodiments, optical unit 30 typically includes an F-theta lens 51 configured to focus each beam following beam direction by the galvo scanner.

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

[0045] Optical unit 30 further includes a camera 54. Before and during the procedure, camera 54 typically captures multiple images of the patient's eye at a relatively high frequency. Controller 44 processes these images and responsively controls radiation source 48 and beam directing elements, as described below with reference to FIGS. 3-4. As shown in FIG. 2, camera 54 may be positioned after beam concentrator 56 such that the camera receives light through the beam concentrator.

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

[0047] The optical unit 30 is mounted on an XYZ stage 32 that 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 in the appropriate position 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 positioning the stage.

[0048] In some embodiments, the XYZ stage 32 includes one or more motors, and the 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 the controller 44. In response to the signals, the controller controls the motors of the XYZ stage. In other embodiments, the XYZ stage 32 is manually controlled by operating the control mechanism.

[0049] Typically, before the radiation source emits a beam toward the eye, the user uses the 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., including respective laser diodes) configured to illuminate the eye with multiple distance-measuring beams 64, e.g., at an angle of 30-100 degrees between the beams. As further described below with reference to FIG. 3 , the distance-measuring beams 64 are shaped to define different respective portions of a predefined composite pattern, such that the predefined composite pattern is formed at the eye only when the optical unit is at the predetermined distance from the eye. Thus, in response to observing the composite pattern, the user can confirm that the optical unit is at the predetermined distance.

[0050] System 20 further includes a headrest 24 attached to a horizontal surface 38, such as a tray or tabletop. Headrest 24 includes a forehead rest 26 and a chin rest 28. During a trabeculoplasty procedure, patient 22 presses their forehead against forehead rest 26 while placing their chin on chin rest 28.

[0051] In some embodiments, the headrest 24 further comprises a securing strap 27 configured to secure the patient's head from behind, thus keeping the patient's head pressed against the headrest. The securing 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 other side of the head, or two segments configured to extend from the headrest on opposite sides of the head and secure to each other behind the head. Optionally, the securing strap may include a sensor configured to detect when the securing strap is properly secured. For example, tightening the securing strap closes an electrical circuit, and the sensor may detect current through the circuit and generate an output in response (e.g., by illuminating 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 generate an output indicating whether the patient's head is resting on the headrest, as desired. Examples of suitable sensors include capacitive, resistive, and piezoelectric sensors. Alternatively or additionally, the headrest may include one or more switches or force-sensitive resistors, such as the Sparkfun® 9375.

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

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

[0055] Typically, as shown in Figure 1, while illuminating a patient's eye, the optical unit is directed obliquely upward toward the eye, while the eye gazes obliquely 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 may 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. Optionally, one or both eyelids can be retracted using a finger, speculum, or another tool for additional exposure of the eye.

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

[0057] Instead of, or in addition to, using the wedge 40, the diagonal direction of the light path can be achieved by tilting the patient's head backward. For example, the forehead rest 26 and / or the chin rest 28 may include length-adjustable straps, and the patient's head may be tilted backward by adjusting the length of the straps. (E.g., the forehead straps may be retracted.) To facilitate this adjustment, the length-adjustable straps may include a worm-type drive, a hook-and-loop fastener, a snap, a locking pin, a knot, and / or any other suitable mechanism.

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

[0059] System 20 further includes a monitor 42 configured to display an image of the eye captured by the camera, as described in more detail below with reference to FIG. 3. Monitor 42 may be positioned in any suitable location, such as on a horizontal surface 38 next to device 21. In some embodiments, monitor 42 includes a touchscreen via which a user inputs commands to the system. Alternatively or additionally, system 20 may include any other suitable input device, such as a keyboard or mouse, that may be used by a user.

[0060] In some embodiments, the monitor 42 is connected directly 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 found in a standard desktop computer.

[0061] It should be emphasized that the configuration shown in Figure 2 is provided by way of example only. Device 21 may include any suitable components, either alternatively or in addition to those shown in Figure 2. For example, device 21 may include an additional illumination source, such as an LED, that the patient can gaze upon during the procedure. Such an illumination source may be located, for example, near 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 can perform at least some of the functions described herein by executing software and / or firmware code. For example, the controller 44 may include a central processing unit (CPU) and random access memory (RAM). Program code and / or data, including software programs, may be loaded into the RAM for execution and processing by the CPU. The program code and / or data may be downloaded to the controller in electronic form, for example, over a network. Alternatively or additionally, the program code and / or data may be provided to and / or stored on non-transitory tangible media, such as magnetic, optical, or electronic memory. Such program code and / or data, when provided to the controller, generates a machine or special-purpose computer configured to perform the tasks described herein.

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

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

[0065] (Pretreatment procedure) Reference is now made to FIG. 3, which is a schematic illustration of a pre-treatment procedure, according to some embodiments of the present invention.

[0066] Initially, the procedure shown in Figure 3 has three steps, designated Steps A through C in the figure. For each of these steps, Figure 3 shows images of eye 25 acquired by camera 54 (Figure 2) and displayed on monitor 42 by controller 44 (Figure 2). Typically, a graphic user interface (GUI) 68 is also displayed alongside each image on monitor 42. 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 associated widgets.

[0067] In step A, the user positions the optical unit 30 (FIG. 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 the appropriate spot size on the eye. As described above with reference to FIG. 2, this positioning is typically facilitated by distance measurement beams 64. They are shaped to define different portions 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, the controller displays a live sequence of images of the patient's eye while the position of the optical unit is being adjusted.)

[0068] For example, as shown in Figure 3, the distance-measuring beam can be shaped to define two perpendicular shapes, such as two perpendicular ellipses, rectangles, or lines that form a cross in 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 that form a circle, or two triangles or arrowheads that form a rhombus or X-shape. Any suitable optical element, such as a diffractive optical element (DOE), a hologram, or an 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 composite pattern 66, the user indicates to the controller that the optical unit is the correct distance from the eye. For example, the user can click the appropriate button on GUI 68. In response to this input, the controller proceeds to step B of the pre-treatment procedure.

[0071] In step B, the controller displays a still image 71 of the eye. Then, based on input from the user, the controller identifies an oval (e.g., circular or nearly circular) portion of the eye, such as the limbus 69 of the eye. For example, the controller may identify the eye portion in response to the user superimposing an oval marker 78 over the eye portion. The position of the oval marker 78 can then be used to calculate the respective positions of the target areas of the treatment beam, as described further below.

[0072] For example, the controller may display, on a static image, both an ellipse marker 78 and a rectangle 80 that circumscribes (or "bounds") the ellipse marker. The user may then adjust the rectangle 80, for example, by dragging the sides or corners of the rectangle using a mouse or touchscreen. (In some embodiments, the system allows the user to switch between coarse and fine adjustment of the rectangle. ) In response to the user's adjustment of the rectangle, the controller may adjust the elliptical marker 78 so that the elliptical marker remains circumscribed by the rectangle until the elliptical marker is overlaid on the user-defined limbus (or another portion of the eye). The user may then indicate to the controller (e.g., via GUI 68) that the elliptical marker is overlaid on the user-defined limbus.

[0073] In some embodiments, the controller overlaps two horizontal lines that touch the top and bottom edges, respectively, of the ellipse marker 78 and two vertical lines that touch the left and right edges, respectively, of the ellipse marker 78, without necessarily causing the lines to intersect with each other and thus define a rectangle. In such embodiments, the user can adjust the ellipse marker 78 by dragging the lines.

[0074] Typically, before allowing the user to adjust the elliptical marker 78, the controller identifies the limbus in the static image using an edge detection algorithm or other suitable image processing technique and then displays the elliptical marker 78 over the limbus. (Note that the controller can approximate the shape of the limbus with any suitable shape, such as an ellipse aligned with vertical and horizontal axes or rotated at any suitable angle.) Advantageously, initializing the placement of the elliptical marker 78 in this manner reduces the time required to adjust the marker. (Because the limbus is generally not a well-defined feature, the location of the limbus identified by the user will typically be slightly different from the location of the limbus initially identified by the controller. Accordingly, the user may adjust the marker as described herein.)

[0075] Instead of or in addition to adjusting the rectangle, the user can directly adjust the elliptical marker 78 by inputting the relevant parameters. For example, in the case of 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 inputs to the limbus identification algorithm executed by the controller (such as a threshold for edge detection). As yet another option, the user can directly manipulate the elliptical marker 78.

[0076] In alternative embodiments, the elliptical marker 78 is not shown at all. In such embodiments, the user can indicate the location of the limbus by dragging a rectangle or line that would bound the marker if it were displayed. As yet another alternative, for greater accuracy, a non-elliptical marker having a different shape that more accurately matches the shape of the limbus 69 can be used in place of the elliptical marker 78.

[0077] Typically, prior to performing the pre-treatment procedure shown in Figure 3, a user will specify (using the GUI 68 or other suitable input interface) the location of each of the multiple target regions relative to the eye portion identified in step B. Alternatively, these parameters may be predefined by the user prior to using the system.

[0078] For example, a user can specify an elliptical path of target areas adjacent to the limbus by specifying the number of target areas and the distance from (or from the center of) the limbus where the center or edge of each target area should be located. Alternatively, a user can specify one or more arc paths by specifying, in addition to the parameters mentioned above, (i) the angular span of each arc, and (ii) the location of each arc. (For example, a user can specify a 180-degree arc around the lower or upper half of the limbus, or a 90-degree arc at the top and bottom.) Based on this input and the user-specified limbus location, the controller typically calculates the location of each of the target areas relative to the center of the limbus identified by the controller. (In some embodiments, the controller calculates the location of the user-specified ellipse or arc, but does not calculate the specific locations of the target areas on the ellipse or arc until after performing step C, described below.)

[0079] As a purely illustrative example, the user may determine whether the center or edge of each target area is at a different respective angle θ relative to the center of the limbus. iThe user can specify that the elliptical marker 78 is at a distance d1 from the limbus marked by the user. Then, 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 the elliptical marker 78 is a circle with radius R, the controller can calculate the offset of the center or edge of each target area from the limbus center by (Δx + (R + d1) cos(θ i ),Δy+(R+d1)sin(θ i )). (Note that d1 may be zero, i.e., the center or edge of each target area may coincide with the limbus marked by the user, such that the center or edge of each of the treatment beams (respectively) strikes the limbus marked by the user. Subsequently, during the procedure, as further described below with reference to FIG. 4, the controller may track the center of the limbus and, for each target area, calculate the position of the target area by adding this offset to the position of the center.

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

[0081] In some embodiments, static region 76 is identified based on the location of the limbus, either automatically identified by the controller or marked by the user. For example, the controller may identify static region 76 as the set of all points within the FOV that are 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 central region 76 at this center point. In such embodiments, static region 76 may have any suitable shape, such as an oval or rectangular shape, and may have any suitable size. The significance of static region 76 is explained below with reference to FIG. 4. (Note that static region 76 is not necessarily displayed on monitor 42.)

[0082] Following step B, the controller proceeds to step C, where the trabeculoplasty procedure is simulated. In response to the display of the simulation, the user may provide a confirming input to the controller, for example, by clicking an appropriate button (such as a "Start" button) on GUI 68. This input confirms that the controller should proceed with the procedure.

[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 one or more aiming beams 84 visible in the images toward the eye. Typically, the aiming beams are red. For example, each aiming beam may have a wavelength between 620 and 650 nm. In some embodiments, the color of the aiming beams is different from the color of the treatment beams. For example, the aiming beams may be red, while the treatment beams may be green, e.g., having a wavelength between 515 and 545 nm (e.g., 532 nm).

[0084] While the aiming beam is projected onto the eye, the controller controls the beam-directing elements so that the treatment beam, when emitted, strikes the calculated target area. Thus, the center of each of the aiming beams may coincide with the center of each target area in turn. Alternatively, if an F-theta lens 51 (FIG. 2) is used and the color of the aiming beam is different from the color of the treatment beam, the chromatic aberration introduced by the F-theta lens may cause the aiming beam to be slightly offset from the target area. Nevertheless, even in this case, the aiming beam typically strikes at least a portion of each target area.

[0085] In some embodiments, the controller sweeps a single aiming beam along the eye such that the aiming beam strikes at least a portion of each target area, while in other embodiments, the controller emits multiple aiming beams, each striking at least a portion of a different target area.

[0086] Typically, while the simulation is running, the controller overlays an elliptical marker 78 over the portion of the eye identified in step B. To correct for eye movement, the controller typically identifies the center of the limbus in each image and places the elliptical marker 78 at an appropriate offset from the limbus. For example, if the final position of the center of the elliptical marker 78 in the still images (step B) is (xo + Δx, yo + Δy), the controller can place the elliptical marker 78 in each live image at an offset of (Δx, Δy) from the center of the limbus.

[0087] Instead of or in addition to overlaying the elliptical marker 78, the controller can overlay another marker 82 on each of the images that passes through (e.g., through the center) or near each target area. The position of the marker 82 can be adjusted in response to eye movement by maintaining the marker 82 at an appropriate offset from the elliptical marker 78. For example, if the center of each target area should be a distance d1 from the limbus marked by the user, the marker 82 can be kept a distance d1 from the elliptical marker 78. In some embodiments, the marker 82 is a different color than the color of the oval marker 78 .

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

[0089] In some embodiments, if the user does not confirm the simulation, the procedure is aborted. In other embodiments, the user can adjust the path followed by the aiming beam (e.g., via GUI 68). This adjustment may be performed by returning to step B and adjusting elliptical marker 78 and / or by adjusting the distance from elliptical marker 78 at which each target region should be located. In such embodiments, the simulation may be repeated for each new path defined by the user until the user confirms the path.

[0090] (Treatment 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 beams is much higher than the peak power of the aiming beam. Furthermore, the wavelength of the treatment beams is typically more suited to treating the trabecular meshwork of the eye compared to the wavelength of the aiming beam.

[0091] More specifically, during treatment, the controller continues to sweep the aiming beam through or emit each aiming beam at the target area while acquiring images of the eye. As further described below with reference to FIG. 4, the controller determines the position of the aiming beam in each image and, in response, emits a treatment beam at the eye. For example, the controller can emit a treatment beam toward the target area struck by the aiming beam or toward the next target area.

[0092] Typically, the controller causes each of the treatment beams to strike the eye outside of a static region 76 (FIG. 3), also referred to herein as a "prohibition zone." (As noted above, static region 76 is static in that the region is defined relative to the camera's FOV and therefore does not move with the eye.) Furthermore, as an added precaution, the controller can prohibit the beam-directing element from directing a beam into (i.e., "passing through") static region 76 even while none of the treatment beams are being emitted. (Typically, the controller also applies these precautions when emitting aiming beams during pre-treatment procedures.)

[0093] Typically, during each image acquisition during a treatment procedure, the controller causes the illumination source 60 (FIG. 2) to flash visible light (e.g., white, red, or green light) into the eye. Thanks to this flash, the required exposure time of the camera can be reduced, for example, by a factor of three or more. Thus, for example, the required exposure time can be reduced from 9 milliseconds to 3 milliseconds. Each flash can begin before or end after the image acquisition. Typically, the peak average intensity over the duration of each flash is 0.003-3 mW / cm.2 , which is generally strong enough to reduce the required camera exposure time and to constrict the eye pupil without harming the patient.

[0094] Typically, the light flashes at a frequency high enough that the patient does not notice the flashes but rather perceives 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., the frequency at which images are acquired), some of the 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 flashes are synchronized with 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 be flashed at a lower frequency, but the duration of each flash may be increased so that steady illumination is perceived. For example, if a patient perceives flickering at a 100 Hz flash frequency and a 20% duty cycle, the duty cycle can be increased to 40% by increasing the pulse width without changing the frequency.

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

[0097] Some further details regarding a trabeculoplasty procedure are provided with reference to FIG. 4, which is a schematic illustration of an exemplary algorithm 86 for performing an automated trabeculoplasty procedure, according to some embodiments of the present invention.

[0098] To begin the procedure after the user approves the simulated procedure, the controller, in an imaging and locating step 88, flashes a light onto the eye, acquires an image of the eye using a camera during the flash, and locates the center of the limbus in the acquired image. Then, in a target calculation step 90, the controller calculates the location of the next target area by adding an appropriate (x,y) offset to the location of the center of the limbus. After verifying this location, the target area is irradiated, as described further below. The controller then acquires another image, calculates the location of the next target area, verifies the location, and irradiates the target. In this manner, the controller repeatedly irradiates the target area.

[0099] More specifically, for each calculated target region, the controller checks whether the target region is (even partially) within a forbidden zone in a first target check step 92, where the forbidden zone, recall, is a static region within the camera's FOV. (To perform this check, the controller does not necessarily need to explicitly calculate the boundary of the target region; for example, the controller might check whether a point at the center of the target region is more than a predefined distance away from the boundary of the forbidden zone—the same as or slightly greater than the radius of the aiming or treatment beam.) If not, the controller performs a second target check step 94, in which, assuming that there is a previous target region before the target region, the controller checks whether the target region is within 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, indicating that the eye is relatively stationary. If the target region is not within an acceptable distance from the previous target region, or if the target region is within a forbidden zone, the controller returns to imaging and localization step 88.

[0100] If the calculated target area passes both the first target check step 92 and the second target check step 94, the controller directs the beam directing element toward the target area in an aiming step 96. The controller then directs the aiming beam toward the beam directing element in an aiming beam emission step 98, whereby the aiming beam is directed by the beam directing element toward the target area. Alternatively, a single aiming beam may be emitted continuously, such that the aiming beam emission step 98 need not be performed.

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

[0102] Following identification of the aiming beam, the controller checks whether the aiming beam is in a prohibited zone in a first aiming beam check step 106. If the aiming beam is in a prohibited zone (indicating rapid eye movement or a system fault), the controller terminates the procedure. Otherwise, the controller checks whether the distance between the aiming beam and the calculated target area is within a predefined threshold in a second aiming beam check step 108. If not, the controller returns to target calculation step 90. If so, the controller emits the treatment beam in a treatment beam emission step 110, where the treatment beam strikes the target area.

[0103] In addition to identifying and confirming the position of the aiming beam, the controller typically checks each image for obstacles that may be obstructing the target area, including, for example, eyelids, eyelashes, fingers, growths (such as pterygium), blood vessels, or a speculum. If an obstacle is identified, the target area can be shifted to avoid the obstacle. Alternatively, the target area can be skipped entirely or the treatment procedure can be terminated.

[0104] In general, obstacles can be identified using any suitable image processing technique, combined with input from a user as a selection. For example, prior to a treatment procedure, a user can select one or more portions of the eye that constitute potential obstacles (e.g., with reference to a static image). The controller can then identify the selected portions of the eye using template matching, edge detection, or other suitable techniques (e.g., including identifying changes between successive images). Such techniques can also be used to identify other static or dynamic obstacles not necessarily identified previously by the user. (Note that the definition of "obstacle" may vary depending on the application; for example, a particular blood vessel may constitute an obstacle, or it may be desirable to irradiate the blood vessel.)

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

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

[0107] In some embodiments, a separate routine executed by the controller monitors the time since each image acquisition, and if this time exceeds a predefined threshold (such as a 10-15 millisecond threshold), the treatment beam is not delivered until the next image is acquired and the target position is recalculated.

[0108] It will be understood by those skilled in the art that the present invention is not limited to what has been particularly shown and described herein, but rather the scope of the present 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 that would occur to one 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 capture an image of the eye; and a controller; A system having: The controller: identifying a static region of the camera's field of view that includes the pupil of the eye based on the image of the eye; and calculating a next position of the target region; determining whether a next one of the target regions is within the static region based on the calculated position; and causing the radiation source to irradiate a next one of the target areas if the next one of the target areas is not within the static region; to repeatedly irradiate the treatment beam from the radiation source to a plurality of target areas of the eye. A system characterized by:

2. further comprising one or more beam directing elements configured to direct the treatment beam toward the target area; 10. The system of claim 1, wherein the controller is further configured to prohibit the beam directing element from being aimed at the static region even while the treatment beam is not being emitted.

3. 2. The system of claim 1, wherein determining whether the next one of the target regions is within the static region comprises checking whether a center of the next one of the target regions is further than a predetermined distance from a boundary of the static region.

4. The system of claim 1 , wherein the static region includes a portion of the cornea of ​​the eye surrounding the pupil.

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

6. The system of claim 5 , further comprising receiving limbus positioning input from a user indicating a location of the limbus.

7. The system of claim 5 , wherein the controller is further configured to identify a location of the limbus.

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

9. The system of claim 5 , wherein the controller is configured to identify the static region by centering the static region at the center of the limbus or the center of the pupil.

10. 10. The system of claim 1, further comprising an optical unit including the radiation source, wherein the controller is configured to cause the radiation source to illuminate the target area while the optical unit is pointed obliquely upwards towards the eye and the eye gazes obliquely downwards towards the optical unit.

11. 11. The system of claim 10, further comprising a wedge, wherein the optical unit is attached to the wedge to direct the optical unit obliquely upward toward the eye.

12. Wedge and; an optical unit attached to the wedge, facing diagonally upward, and having a radiation source; and a controller configured to treat the patient's eye by causing the radiation source to deliver one or more treatment beams to one or more target areas of the eye while the eye gazes obliquely downward toward the optical unit; A system comprising:

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

14. The system of claim 13 , wherein the controller is configured to process the image to identify the one or more target regions.

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

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

17. 17. The system of any one of claims 12 to 16, wherein the wedge is configured to point the optical unit upwards at an angle between 5 degrees and 20 degrees.

18. 18. The system of claim 12, 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