Direct Selective Laser Trabeculoplasty

Abstract

To provide ophthalmological devices and methods for treatment of glaucoma, ocular hypertension (OHT), and other diseases.SOLUTION: A system 20 includes a radiation source and a controller. The controller is configured to: display a live sequence of images of an eye 25 of a patient 22; while displaying the sequence of images of the eye, cause the radiation source to irradiate the eye with one or more aiming beams, which are visible in the images; subsequently cause 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.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, titled "Direct Selective Laser Trabeculoplasty Process (DSLT) and Safety", filed on Jul. 2, 2018 (Patent Document 1); (ii) U.S. Provisional Patent Application No. 62 / 739,238, titled "Eye Tracking Flash Illumination", filed on Sep. 30, 2018 (Patent Document 2); and (iii) U.S. Provisional Patent Application No. 62 / 748,461, titled "Cross - ranging Beam", filed on Oct. 21, 2018 (Patent Document 3). The disclosures of each of those respective references are 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., "Selective laser trabeculoplasty without a keratoscope lens", 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 lens.

[0005] Belkin U.S. Patent Application Publication No. 2015 / 0366706 (Patent Document 4), the disclosure of which is incorporated herein by reference, describes an apparatus including a probe and a processor. The probe is arranged adjacent to a patient's eye and configured to irradiate one or more light beams onto the eye's trabecular meshwork. 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

Patent Document 2

Patent Document 3

Patent Document 4

Non-Patent Documents

[0007]

Non-Patent Document 1

Summary of the Invention

[0008] According to some embodiments of the present invention, a system having a radiation source and a controller is provided. 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 irradiate one or more aiming beams visible in the image onto the eye. The controller is further configured to, after causing the radiation source to irradiate the aiming beams 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 irradiate a plurality of treatment beams onto respective target regions of the eye.

[0009] In some embodiments, it further comprises a focusing lens and one or more beam steering 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 towards the beam steering element, whereby the beam is focused by the focusing lens before being directed by the beam steering element towards respective target regions.

[0010] In some embodiments, the aiming beam impinges on at least a portion of each target region. In some embodiments, the controller is further configured to overlay a marker passing through each target region over 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 from the limbus.

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

[0012] In some embodiments, the controller is configured to confirm 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 impinges on each portion of the eye where the marker is superimposed. In some embodiments, the marker is oval.

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

[0014] In some embodiments, following the identification of the oval portion of the eye, the controller identifies the deviation from the center of the corneal limbus of the eye to the center of the oval portion of the still image, and for each image of the images: identifies the center of the corneal limbus in the image, and superimposes the oval marker on the image such that the center of the oval marker is at the identified deviation from the center of the corneal limbus, thereby superimposing the oval marker over the oval portion of the eye.

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

[0016] In some embodiments, the system further comprises a camera configured to acquire an image and, prior to acquiring the image, acquire a still image of the 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 still 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 onto the beam steering elements, and wherein the controller is further configured to prohibit the beam steering elements 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 limbus position identification input indicating the position of the limbus in the still image; and identifying the static region based on the position 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 a plurality of second images of the eye while treating the eye, and wherein the controller is configured to repeatedly: 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 its respective target region is less than a predetermined threshold. In some embodiments, the controller is configured to emit each one treatment beam towards its respective target region. In some embodiments, it further comprises an illumination source, wherein the controller is further configured to intermittently flash visible light towards the eyes so as to illuminate the eyes, 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 so that the illumination source illuminates the eyes 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 eyes for the illumination source, during the treatment of the eyes. 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 cause the plurality of distance measurement beams to be irradiated towards the eyes for the beam emitters, before causing the aiming beam to be irradiated towards the eyes 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 eyes only when the optical unit is at a predetermined distance from the eyes.

[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 cause the radiation source to irradiate a target area, while the optical unit is directed obliquely upward towards the eyes and the eyes are positioned obliquely downward towards the optical unit. In some embodiments, a wedge is further provided, and the optical unit is oriented obliquely upward toward the eye by being attached to the wedge.

[0023] According to some embodiments of the present invention, there is provided a system comprising: a wedge; an optical unit attached to 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 irradiating a plurality of treatment beams to respective target regions of the eye with respect to the radiation source while the eye is gazing obliquely downward toward the optical unit.

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

Brief Description of the Drawings

[0025] The present invention will be more fully understood from the following detailed description of its embodiments with reference to the drawings:

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0026] (Summary) Embodiments of the present invention provide an automated trabeculoplasty device configured to perform a trabeculoplasty procedure safely and efficiently 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 will be 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 assist in aiming the treatment beam.

[0027] Typically, prior to the procedure, the controller displays a live video of the eye with two ellipses superimposed thereon: an inner ellipse that shows the corneal limbus of the eye and an outer ellipse that is slightly displaced from the inner ellipse and passes through or near each target region to be irradiated by the treatment beam. The controller further typically simulates the procedure by sweeping the aiming beam on the outer ellipse such that the aiming beam impinges on at least a portion of each target region. Advantageously, this simulation can assist the physician in visualizing the path along the eye that the treatment beam will target, i.e., the path in which the target regions are located. After the physician has confirmed the target path along the eye, the controller causes the radiation source to emit the treatment beam towards the target region.

[0028] Since each beam of radiation generally strikes the eye with a non - microscopic spot size, it should be noted that this application generally describes each beam as striking an "area" of the eye, the area of which is a function of the spot size, rather than striking a "point" of the eye. Thus, for example, this application is concerned with a "target area" rather than a "target point". Nevertheless, in the context of this application, including the claims, a reference to calculating the position of the target area can implicitly refer to calculating the position of a single point within the area, such as the center or an end of the area towards which the center or an end of the beam (respectively) is directed. (Subsequently, even if the center or an end of the beam is slightly displaced from the calculated point, this application, including the claims, can be considered to have the beam strike the calculated target area.)

[0029] Typically, before simulating the above procedure, the controller acquires a still image of the eye and identifies the limbus within the still image. Next, the controller superimposes the aforementioned inner ellipse over the limbus. Subsequently, the controller allows the physician to modify the position and / or shape of the inner ellipse, such that the inner ellipse marks the limbus as defined by the physician. (Since the limbus is generally not clearly defined, the position of the limbus for each physician may vary slightly from the position automatically identified by the controller.) For example, the controller may enclose the inner ellipse with a rectangle and permit the physician to adjust the ellipse by dragging the sides or corners of the circumscribing rectangle.

[0030] As observed by the inventors, the fibrous trabecular band can be most effectively irradiated when the treatment beam impinges on or near the corneal limbus of the eye, and the corneal limbus can be identified by the user as described above or automatically identified by the controller. Thus, in some embodiments of the present invention, the controller causes the radiation source to target a portion of the eye at or near the corneal limbus. For example, at least a portion of each target area may be located within 1 mm (e.g., within 400 microns) from the corneal limbus. As a specific example above, the center of each target area is located within 1 mm (e.g., within 400 microns) from the corneal limbus, whereby the center of each treatment beam can impinge on the eye within 1 mm (e.g., within 400 microns) of the corneal limbus.

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

[0032] Furthermore, as an additional safety measure, the controller can define, in the aforementioned still image, a region referred to herein as the "prohibited zone". The prohibited zone typically encompasses the pupil of the eye along with a portion of the eye surrounding the pupil. The prohibited zone is defined within the field of view (FOV) of the camera and is static in that it is not adjusted in response to detected eye movement. Next, the controller can prevent any of the treatment beams from hitting the prohibited zone. Additionally, the controller can prevent the beam directing element from being directed towards the prohibited zone even while the radiation source is in a standby state. Thus, the retina of the eye is protected from potential (albeit low probability) stray beams.

[0033] In some embodiments, the trabeculoplasty device further includes a visible light source, and the controller is configured to flash visible light towards the eye with the visible light source, such that the visible light is turned on at least while each image is being acquired. Advantageously, the flash shortens the time required for image acquisition, and as a result, the position of the target region calculated in response to the image does not move significantly before the aiming beam or treatment beam is emitted to the target region. Further, the flash can constrict the pupil of the eye and thus further protect the retina from potential stray beams.

[0034] Typically, the flash occurs at a frequency high enough and / or each pulse of light has a long enough duration such that the flash is not noticed 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, to shorten the time required for image acquisition without causing discomfort to the patient, the eye can be illuminated with near-infrared light. Additionally, as an option, visible light can be flashed towards the eye such that the visible light is turned on while the image is being acquired and / or in between image acquisitions.

[0036] Embodiments of the present invention further provide a technique for facilitating the placement 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 measurement beams from the device to the eye and moving the device closer to or farther from the eye until the two beams overlap. However, as the inventors have observed, for several reasons, it may be difficult to use this technique for positioning a trabeculoplasty device. For example, since the sclera is covered by the conjunctiva, it may distort and reflect the distance measurement beam, making it impossible to distinguish that the beams overlap. Thus, in embodiments of the present invention, the distance measurement beams are given different respective shapes such that the beams form a specific pattern only when the trabeculoplasty device is placed at the correct distance from the eye. For example, the distance measurement beams are formed as orthogonal ellipses, and the distance measurement beams form a cross over 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 such that the camera and radiation source are angled upward. Next, the patient's line of sight is directed obliquely downward toward the optical unit so that the upper portion of the patient's sclera is exposed.

[0038] Although the description herein is mainly related to trabeculoplasty, the techniques described herein are also applicable to photocoagulation, iridectomy, capsulotomy, lens removal, or other related ophthalmic surgeries. The target of the radiation 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] (Description of the System) First refer to FIG. 1, which is a schematic diagram of a system 20 including a trabeculoplasty device 21 for performing trabeculoplasty according to some embodiments of the present invention. Further refer to FIG. 2, which is a schematic diagram of a trabeculoplasty device 21 according to some embodiments of the present invention.

[0040] The fiber column band forming device 21 includes an optical unit 30. The optical unit 30 includes 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 galvanometer mirrors 50 (collectively referred to as "galvo scanners") and / or a beam concentrator 56. Prior to 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 above the eye 25 such that the beam is directed to the target area by the beam directing elements. For example, the beam can be deflected by the galvanometer mirror 50 towards the beam concentrator 56, and then the beam can be deflected through the aperture 58 in the front face of the optical unit such that the beam impinges on the target area. Each beam emitted by the radiation source can have an elliptical (e.g., circular), square, or any other suitable shape.

[0041] Typically, the radiation source is composed of two lasers. One is for emitting the aiming beam described herein, and the other is for emitting the treatment beam described herein. As a purely illustrative example, the treatment laser can include an Ekspla® NL204-0.5K-SH laser (modified to include, for example, an attenuator, an energy meter, and a mechanical shutter), while the aiming laser can include a Laser Components® FP-D-635-1DI-CF laser. Typically, both the aiming beam and the treatment beam include visible light.

[0042] As an alternative or addition to the laser, the radiation source can include any other suitable emitter configured to emit radiation belonging to any suitable portion 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 galvanometer scanner, which expands and then re-collimates the beam. In such embodiments, the optical unit 30 typically includes an F-theta lens 51 configured to focus each beam following the directioning of the beam by the galvanometer scanner.

[0044] In other embodiments, the focusing lens is disposed between the radiation source and the galvanometer scanner. For example, the aforementioned beam expander 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 such that the F-theta lens 51 is not required.

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

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

[0047] The optical unit 30 is attached to 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 an appropriate position before treating the patient's eye. In some embodiments, the XYZ stage 32 includes a locking element configured to prohibit movement of the stage after positioning of 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 the user operates the control mechanism, the interface circuit 46 converts this activity into appropriate electrical 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 manually controlled by operating the control mechanism.

[0049] Typically, before the radiation source emits a beam towards 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 a plurality of beam emitters 62 (e.g., each including a respective laser diode), which are configured to irradiate the eye with a plurality of distance measurement beams 64, and for example, the angle between the beams is 30 - 100 degrees. As will be further described below with reference to Figure 3, the distance measurement beams 64 are shaped to define respective different portions of a predefined composite pattern, and the predefined composite pattern is formed on 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 includes a headrest 24 attached to 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 fiber trabeculoplasty procedure, the patient 22 presses their forehead against the forehead rest 26 while placing their chin on the 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 and thus hold the patient's head against the headrest. The securing strap 27 may extend from the headrest on one side of the head and be configured to secure to the headrest on the opposite side of the head, or may comprise a single segment extending from the headrest on opposite sides of the head and configured to secure to each other behind the head. Alternatively, the securing strap may include a sensor configured to detect that the securing strap is properly secured. For example, when the securing strap is tightened, an electrical circuit is closed and the sensor may detect a current passing 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 can be disposed, for example, on the forehead rest or the chin rest. Each of these sensors can be configured to generate 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 comprise one or more switches or force-sensitive resistors such as Sparkfun® 9375.

[0053] In some embodiments, a physical block is disposed around the eyes to block radiation reflected by the eyes. For example, the hood may be disposed over the chin rest and / or over 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 that is attached to the horizontal plane 38, and the XYZ stage 32 is attached to the base unit 34. In such embodiments, the controller 44 and the interface circuit 46 may be disposed within the base unit. In other embodiments, the XYZ stage is directly attached to the horizontal plane 38.

[0055] Typically, as shown in FIG. 1, while irradiating the patient's eye, the optical unit is directed obliquely upward toward the eye, and one eye gazes obliquely downward toward the optical unit, i.e., the optical path 23 between the eye and the optical unit is not horizontal but oblique. For example, the optical path 23 can be oriented at an angle θ between 5 and 20 degrees. Advantageously, this orientation reduces interference of the patient's eye by the patient's upper eyelid and related anatomical structures. Alternatively, to further expose the eye, one or both eyelids can be retracted using a finger, an ophthalmoscope, or another tool.

[0056] In some embodiments, as shown in FIG. 1, the oblique direction of the optical path is achieved by an optical unit attached to a wedge 40 attached to the XYZ stage. 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 oblique direction of the optical 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 can be tilted backward by adjusting the length of the straps. (For example, the forehead strap can be retracted.) To facilitate this adjustment, the length-adjustable straps can include a worm-type drive, 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) towards the optical unit, so that as a result, the patient's head rests more firmly on the headrest.

[0059] As will be described in detail below with reference to FIG. 3, the system 20 further comprises a monitor 42 configured to display an image of the eyes acquired by the camera. The monitor 42 can be arranged at any suitable position, such as on the horizontal plane 38 next to the device 21. In some embodiments, the monitor 42 includes a touch screen through which the user can input commands to the system. Alternatively or additionally, the system 20 can include any other suitable input device, such as a keyboard or a mouse, that 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 is emphasized that the configuration shown in FIG. 2 is provided by way of example only. The device 21 can further include any suitable components, alternatively or additionally to the components shown in FIG. 2. For example, the device can include an additional light source, such as an LED, on which the patient can fixate during the treatment. Such a light source can be arranged, 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 using, for example, 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 can include a central processing unit (CPU) and random access memory (RAM). Program code and / or data, including software programs, can be loaded into the RAM for execution and processing by the CPU. The program code and / or data can be downloaded to the controller in electronic form, for example, via a network. Alternatively or additionally, the program code and / or data can be provided and / or stored on a non-transitory tangible medium such as magnetic, optical, or electronic memory. When such program code and / or data are provided to the controller, they generate a machine or a dedicated computer configured to perform the tasks described herein.

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

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

[0065] (Pretreatment procedure) Now, refer to FIG. 3, which is a schematic diagram of a pretreatment procedure according to some embodiments of the present invention.

[0066] First, the procedure shown in FIG. 3 has three steps, called steps A - C in the figure. FIG. 3 shows an image of the eye 25 obtained by the camera 54 (FIG. 2) and displayed on the monitor 42 by the controller 44 for each of these steps. Usually, a graphical user interface (GUI) 68 is further displayed next to each image on the 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 (FIG. 2) such that the center of the eye is approximately at 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 on the eye. As described above with reference to FIG. 2, this positioning is typically facilitated by the distance measurement beam 64. They are shaped to define different respective parts of a predefined composite pattern 66, such that the pattern 66 is formed on the eye only when the optical unit is at the correct distance. Usually, the user forms the composite pattern on the sclera of the eye near the corneal limbus. (Typically, while the position of the optical unit is being adjusted, the controller displays a live sequence of images of the patient's eye.)

[0068] For example, as shown in FIG. 3, the distance measurement beam can be shaped to define two perpendicular shapes, such as two perpendicular ellipses, rectangles, or lines that form a cross on the eye only when the optical unit is at the correct distance. Alternatively, the distance measurement beam can be shaped to define two arcs or semi - circles that form a circle, or two triangles or arrows that form a rhombus or an X - shape. To facilitate the generation of these patterns, any suitable optical element, such as a diffractive optical element (DOE), a hologram, or an axicon, can be used.

[0069] In other embodiments, only a single ranging beam is emitted and a computer-generated pattern is overlaid on the image of the eye. When the optical unit is at the correct distance, the ranging 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 an appropriate button on the 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. Subsequently, based on input from the user, the controller identifies an elliptical (e.g., circular or substantially circular) portion of the eye, such as the limbus 69 of the eye. For example, the controller can identify the portion of the eye in response to the user overlaying an elliptical marker 78 over the portion of the eye. Next, as further described below, the position of the elliptical marker 78 can be used to calculate the respective positions of the target regions of the treatment beam.

[0072] For example, the controller can display both the elliptical marker 78 and a rectangle 80 that circumscribes (or "defines the boundary of") the elliptical marker on the still image. Subsequently, the user can adjust the rectangle 80, for example, by dragging the sides or corners of the rectangle using a mouse or touch screen. (In some embodiments, the system enables the user to switch between a rough and a fine adjustment of the rectangle.) In response to the user's adjustment of the rectangle, the controller can adjust the elliptical marker 78 so that the elliptical marker remains circumscribed by the rectangle until the elliptical marker is overlaid on the limbus (or another portion of the eye) defined by the user. Subsequently, the user can indicate to the controller (e.g., via the GUI 68) that the elliptical marker is overlaid on the limbus defined by the user.

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

[0074] Typically, before enabling the user to adjust the elliptical marker 78, the controller uses an edge detection algorithm or other suitable image processing technique to identify the limbus in a still image 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 the vertical and horizontal axes or rotated at any suitable angle.) Advantageously, by initializing the placement of the elliptical marker 78 in this way, the time required for marker adjustment is reduced. (Since the limbus is generally not a well-defined feature, the position of the limbus identified by the user is usually slightly different from the position of the limbus initially identified by the controller. Thus, as described herein, the user can adjust the marker.)

[0075] Instead of or in addition to adjusting the rectangle, the user can directly adjust the elliptical marker 78 by entering the relevant parameters. For example, in the case of an elliptical (e.g., circular) marker, the user can enter 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 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 an alternative embodiment, the elliptical marker 78 is not shown at all. In such an embodiment, the user can indicate the position of the limbus by dragging a rectangle or a line that would have bounded the marker if the marker were displayed. 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 in place of the elliptical marker 78.

[0077] Typically, before performing the pretreatment procedure shown in FIG. 3, the user designates (using GUI 68 or other suitable input interface) the position of each of a plurality of target regions with respect to the portion of the eye identified in step B. Alternatively, these parameters can be predefined before the user uses the system.

[0078] For example, the user can specify an elliptical path of a target region adjacent to the limbus by specifying the number of target regions and the distance from (or from the center of) the limbus at which the center or end of each target region should be located. Alternatively, in addition to the aforementioned parameters, the user can specify the path of one or more arcs by specifying (i) the angular span of each arc, and (ii) the position of each arc. (For example, the user can specify an arc of 180 degrees around the lower or upper half of the limbus, or arcs of 90 degrees each at the top and bottom.) Based on this input and on the position of the limbus 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 position of the ellipse or arc specified by the user, but does not calculate the specific position of the target region on the ellipse or arc until after performing step C described below.)

[0079] As a purely illustrative example, the user can specify that the center or edge of each target region is at a respective angle θ with respect to the center of the limbus iThus, it can be specified that it is at a distance d1 from the corneal limbus marked by the user. Next, during step B, the user can adjust the elliptical marker 78 such that the center of the marker is at (x0 + Δx, y0 + Δy), where (x0, y0) is the center of the corneal limbus identified by the controller. In such a case, assuming that the elliptical marker 78 is a circle with radius R, the controller determines the offset from the center of each target region or the corneal limbus center at the end of the corneal limbus as (Δx+(R + d1)cos(θ i ), Δy+(R + d1)sin(θ i )) (note that d1 can be zero, i.e., the center or edge of each target region may coincide with the corneal limbus marked by the user, and the center or edge of each treatment beam collides with the corneal limbus marked by the user respectively). Subsequently, during the procedure, as will be further described below with reference to FIG. 4, the controller can track the center of the corneal limbus and, for each target region, calculate the position of the target region 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 the "forbidden zone") within the field of view (FOV) of the camera that includes the pupil 74, along with a "buffer" that includes a substantial portion of the eye's cornea 72 that normally surrounds the pupil 74. Usually, 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 automatically by the controller or marked by the user based on the position of the limbus of the cornea. For example, the controller can identify the static region 76 as the set of all points within the FOV that are located inside the limbus of the cornea beyond a predefined distance from the limbus. Alternatively, for example, the controller can identify a point at the center of the limbus or the center of the pupil and then identify the central region 76 at this central point. In such embodiments, the static region 76 can have any suitable shape, such as an oval or rectangular shape, and can have any suitable size. The importance of the static region 76 is described below with reference to FIG. 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 procedure for trabeculoplasty is simulated. In response to the display of the simulation, the user can provide a confirmation input to the controller, for example, by clicking an appropriate button (such as a "start" button) on the GUI 68. This input confirms that the controller needs to continue with the procedure.

[0083] More specifically, in step C, the controller displays a live sequence of images of the eye (i.e., a live video) and, while the sequence of images is being displayed, irradiates one or more aiming beams 84 visible in the images towards the eye. Typically, the aiming beam is red. For example, each aiming beam can have a wavelength of 620 - 650 nm. In some embodiments, the color of the aiming beam is different from the color of the treatment beam. For example, the aiming beam can be red, while the treatment beam can be green with a wavelength of, for example, 515 - 545 nm (e.g., 532 nm).

[0084] While irradiating the aiming beam onto the eye, the controller controls the beam directing element so that if the treatment beam is emitted, the treatment beam collides with the calculated target area. Thus, the center of each aiming beam can sequentially coincide with the center of each target area. Alternatively, when using the F-theta lens 51 (FIG. 2) and the color of the aiming beam is different from the color of the treatment beam, due to the chromatic aberration introduced by the F-theta lens, the aiming beam may be slightly displaced from the target area. Nevertheless, even in this case, the aiming beam usually collides with at least a part 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 part of each target area. In other embodiments, the controller emits a plurality of aiming beams, and each aiming beam collides with at least a part of a different respective one target area.

[0086] Typically, during the execution of the simulation, the controller superimposes the elliptical marker 78 on the part of the eye identified in step B. To correct for eye movement, the controller typically identifies the center of the corneal limbus of each image and then appropriately displaces from the corneal limbus to place the elliptical marker 78. 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 place the elliptical marker 78 in each live image at a displacement of (Δx, Δy) from the center of the corneal 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, passing through (e.g., through the center) or near each target region. The position of the marker 82 can be adjusted in response to eye movement 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 corneal limbus marked by the user, the marker 82 can be maintained at a distance d1 from the elliptical marker 78. In some embodiments, the marker 82 is a different color than the color of the elliptical marker 78.

[0088] Typically, during the execution of the simulation, the controller confirms that each of the aiming beams is properly directed by the beam directing element. For example, the controller can process a feedback signal from the encoder of the galvo mirror 50. Alternatively or additionally, the controller can confirm the respective position of the aiming beam with respect to the elliptical marker 78, the marker 82, and / or other suitable markers overlaid on each image by processing the image. For example, the controller can confirm that each aiming beam (e.g., the center of each aiming beam) overlaps the marker 82 and / or that the end of each aiming beam contacts the elliptical marker 78. (In the context of this application, including the claims, the "end" of the beam can be defined in terms of a knife edge measurement, a 1 / e 2 width measurement, a full width at half maximum measurement, or other suitable measurement.) As another example, the controller confirms that the center or end of each aiming beam is disposed at an appropriate distance from the elliptical marker 78. In response to the confirmation of the position of the aiming beam, the controller can proceed with the trabeculoplasty procedure if the user provides the aforementioned confirmation 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 that the aiming beam follows (e.g., via the GUI68). This adjustment can be performed by returning to step B and adjusting the elliptical marker 78 and / or by adjusting the distance from the elliptical marker 78 at which each target area is to be placed. In such embodiments, the simulation can 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 areas with respective treatment beams. The peak power of the treatment beam is much higher than the peak power of the aiming beam. Further, typically, the wavelength of the treatment beam is more suitable for treating the fiber trabecular meshwork of the eye as compared to the wavelength of the aiming beam.

[0091] More specifically, during treatment, the controller continues to sweep the aiming beam through the target area or emits the respective aiming beams to the target area while acquiring an image of the eye. As will be further described below with reference to FIG. 4, the controller checks the position of the aiming beam within each image and, in response, emits a treatment beam to the eye. For example, the controller can emit the treatment beam towards the target area where the aiming beam has collided or towards the next target area.

[0092] Typically, the controller causes each of the treatment beams to impinge on the eye outside a static region 76 (FIG. 3), also referred to herein as the "prohibited zone." (As noted above, the static region 76 is static in that the region is defined with respect to the camera's FOV and thus does not move with the eye.) Further, as an additional precaution, the controller can prohibit the beam steering element from being directed (i.e., "passed through") by the treatment beam, even when no treatment beam is being emitted, into the static region 76. (Typically, the controller applies these precautions when emitting the aiming beam during the pretreatment procedure as well.)

[0093] Typically, while each image is being acquired during the treatment procedure, the controller causes the illumination source 60 (FIG. 2) to flash visible light (e.g., white light, red light, or green light) into the eye. Due 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 acquisition of the image. Typically, the peak average intensity over the duration of each flash is 0.003 - 3 mW / cm 2 which is generally of sufficient intensity to reduce the required exposure time of the camera and contract the pupil of the eye without harming the patient.

[0094] Typically, the light flashes at a frequency high enough so that the patient does not notice the flash and rather perceives a stable illumination. For example, the light can be flashed 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, for example, less than 2 milliseconds or less than 1 millisecond.) Since the flash frequency is higher than the frame rate (i.e., the frequency at which images are acquired), part of a flash may occur during image acquisition. For example, the flash frequency can be an integer multiple of the frequency at which images are acquired such that the flash is synchronized with the image acquisition. As a purely illustrative example, if the frame rate is 60 Hz, the flash frequency can be 120 Hz or 180 Hz.

[0095] Alternatively, the light may be flashed at a lower frequency, but the duration of each flash can be increased so that stable illumination is perceived. For example, if a patient perceives flicker at 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, during the procedure, or at least while an image is being acquired, near-infrared light can be continuously irradiated to shorten the required camera exposure time without disturbing the patient. As an option, the illumination source 60 can also flash visible light towards the eye during and / or between image acquisitions to further shorten the required exposure time and / or constrict the pupil.

[0097] Referring to FIG. 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 regarding the trabeculoplasty procedure are provided.

[0098] To start the procedure after the user approves the simulated procedure, the controller, in the imaging and localization step 88, flashes light towards the eye, uses the camera during the flash to acquire an image of the eye, and identifies the position of the center of the corneal limbus in the acquired image. Subsequently, in the 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 corneal limbus. After verifying this position, the target area is irradiated, as further explained below. Next, the controller acquires another image, calculates the position of the next target area, verifies the position, and irradiates the target. In this way, the controller repeatedly irradiates the target area.

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

[0100] If the calculated target area passes through both the first target check step 92 and the second target check step 94, the controller, in the aiming step 96, directs the beam directing element towards the target area. Then, in the aiming beam emission step 98, the controller emits the aiming beam towards the beam directing element, whereby the aiming beam is directed towards the target area by the beam directing element. Alternatively, a single aiming beam can be emitted continuously, such that there is no need to perform the aiming beam emission step 98.

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

[0102] Following the identification of the aiming beam, the controller checks in the first aiming beam check step 106 whether the aiming beam is in a prohibited zone. If the aiming beam is in the prohibited zone (indicating a rapid eye movement or a system malfunction), the controller terminates the procedure. Otherwise, in the second aiming beam check step 108, the controller checks whether the distance between the aiming 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 the treatment beam in the treatment beam emission step 110, and the treatment beam collides with the target area.

[0103] Typically, in addition to identifying and verifying the position of the aiming beam, the controller checks each image for obstacles that may be obstructing the target area, including, for example, the eyelids, eyelashes, fingers, growths (such as wing-like pieces), blood vessels, or the speculum. If an obstacle is identified, the target area can be shifted to avoid the obstacle. Alternatively, the target area can be completely skipped, or the treatment procedure can be terminated.

[0104] Generally, obstacles can be identified using any suitable image processing technique, optionally in combination with input from the user. For example, prior to the treatment procedure, the user can select one or more parts of the eye that constitute potential obstacles (e.g., by referring to a still image). Subsequently, the controller can use template matching, edge detection, or other suitable techniques (including, for example, identifying changes between successive images) to identify the selected parts of the eye. Such techniques can also be used to identify other static or dynamic obstacles that the user may not have pre-identified. (Note that the definition of "obstacle" may vary depending on the application. For example, in some cases, a particular blood vessel may constitute an obstacle, while in other cases, it may be desirable to irradiate the blood vessel.)

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

[0106] Advantageously, the time between the acquisition of each image and the emission of the treatment beam is typically less than 15 milliseconds, for example, less than 10 milliseconds. In some embodiments, this delay is reduced further by emitting the treatment 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 confirm retrospectively that the treatment beam has been emitted correctly.)

[0107] In some embodiments, a separate routine executed by the controller monitors the time from each image acquisition. If this time exceeds a predefined threshold (such as a 10 - 15 millisecond threshold), the treatment beam is not emitted 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. Rather, the scope of the invention includes both the various combinations and sub - combinations of the features described above, as well as those variations and modifications thereof which are not found in the prior art that will occur to those skilled in the art upon reading the foregoing description.

Claims

1. A radiation irradiation source configured to emit a therapeutic beam of radiation; A camera configured to acquire an image of an eye; and A controller; A system having, wherein the controller: Based on the image of the eye, identifies a static region of the field of view of the camera that includes the pupil of the eye, and Calculates the next position of a target region; Based on the calculated position, checks whether the next target region is within the static region; and When the next target region is not within the static region, causes the radiation irradiation source to irradiate the next target region; Repeatedly configured to irradiate the plurality of target regions of the eye with the therapeutic beam from the radiation irradiation source. A system characterized by this.

2. Further comprising one or more beam directing elements configured to direct the therapeutic beam toward the target region, The controller is further configured to prohibit the beam directing element from being directed toward the static region even when the therapeutic beam is not being emitted. The system according to claim 1, characterized by this.

3. The step of checking whether the next target region is within the static region includes checking whether the center of the next target region is farther than a predetermined distance from the boundary of the static region. The system according to claim 1, characterized by this.

4. The static region includes a part of the cornea of the eye surrounding the pupil. The system according to claim 1, characterized by this.

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

6. Further comprising receiving from the user a corneal limbus positioning input indicating the position of the corneal limbus. The system according to claim 5, characterized by this.

7. The controller is further configured to identify the position of the corneal limbus. The system according to claim 5, characterized by this.

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

9. The system according to claim 5, wherein the controller is configured to identify the static region by placing the center of the static region at the center of the limbal region 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 irradiation source, wherein the controller is configured to cause the radiation irradiation source to irradiate the target region while the optical unit is directed obliquely upward toward the eye and the eye is looking obliquely downward toward the optical unit.

11. The system according to claim 10, further comprising a wedge, wherein the optical unit is directed obliquely upward toward the eye by being attached to the wedge.

12. A wedge; An optical unit attached to the wedge, directed obliquely upward, and having a radiation irradiation source; and A controller configured to treat the eye of a patient by irradiating one or more treatment beams to one or more target regions of the eye with respect to the radiation irradiation source while the eye is looking obliquely downward toward the optical unit. A system, characterized by comprising:

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, wherein the controller is configured to process the image to identify the one or more target regions.

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

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

17. The system according to any one of claims 12 to 16, wherein the wedge is configured to direct the optical unit upward by an angle between 5 degrees 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 head of the patient in an oblique direction with respect to the optical unit.

Images