Patent Application
20130110092
Therapeutic lasers are often used to treat various conditions of the eye. For example, a specific type of condition that may be treated with such lasers is diabetic retinopathy. Diabetic retinopathy, is damage to the retina that is due to complications of diabetes. If left untreated, diabetic retinopathy can eventually lead to blindness. Diabetic retinopathy typically results from microvascular retinal changes. For example, diabetic induced effects may damage tissue of the eye, which may change the formation of the blood-retinal barrier and make the retinal blood vessels become more permeable. In treating such conditions, one or more light beams may be directed into the eye and/or onto retinal tissue to cause photocoagulation of the tissue so as to finely cauterize ocular blood vessels and/or prevent blood vessel growth to induce various therapeutic benefits. Laser photocoagulation is commonly used for early stages of retinopathy.
In providing laser photocoagulation treatments, however, it is important to avoid damaging sensitive tissue of the eye, such as the fovea, macula, and the like. In certain instances, it may be desired to treat tissue close to one or more of these areas while ensuring that damage to such areas is avoided. Conventional laser photocoagulation techniques do not offer optimal solutions to treating areas close to such sensitive tissue while ensuring that damage to such tissue will be avoided or greatly reduced. Accordingly, there is a need in the art for improved laser photocoagulation methods for treating various conditions of the eye, such as diabetic retinopathy.
Embodiments of the invention described herein provide systems and methods for treating retina tissue and/or other areas of a patient's eye. The procedures may involve using one or more light beams (e.g., lasers) to cause photocoagulation to finely cauterize ocular blood vessels and/or prevent blood vessel growth to induce one or more therapeutic benefits. Such procedures may be used to treat diabetic retinopathy, macular edema, and/or other conditions of the eye. According to one aspect, a method for treating an eye of a patient is provided. The method may include providing a retinal image of the patient's eye and determining first and second treatment areas of a retina to treat with a therapeutic treatment by referencing the retinal image. A beam may be directed toward the first determined treatment area of the retina by referencing the retinal image so as to produce the therapeutic treatment for the first treatment area. Indicia of the therapeutic treatment may be superimposed on the retinal image at a first location corresponding to the first treatment area. The beam may also be directed onto the second determined treatment area of the retina by referencing the retinal image with the superimposed indicia so as to produce the therapeutic treatment for the second treatment area.
According to some embodiments, the method may also include superimposing indicia of the therapeutic treatment on the retinal image at a second location corresponding to the second treatment area and storing the retinal image with the super imposed indicia so as to track the treatments the patient receives. The method may further include superimposing on the retinal image, a plurality of therapeutic treatments provided to or to be provided to the patient.
According to some embodiments, a movement of the patient's eye may be determined or detected and, in response to the movement, a position of the beam may be adjusted to compensate for the movement. Adjusting a position of the beam may include capturing a second retinal image of the eye and comparing retinal features of the retinal image with retinal features of the second retinal image.
According to some embodiments, determining a first treatment area may include determining a treatment boundary that separates retinal tissue to a first area and a second area. In such embodiments, the method may additionally include delivering the therapeutic treatment to the first treatment area by selectively directing the beam within the treatment boundary. In addition, an additional beam may be directed on retinal tissue to define or superimpose the treatment boundary on the retinal tissue. The method may additionally include superimposing the treatment boundary on the retinal image to display the therapeutic treatment for the first treatment area. The retinal image and superimposed treatment boundary may additionally be displayed on a display device that is configured to accept a user input to adjust a property of the treatments boundary. The property that may be adjusted may include: a boundary shape, a boundary size, a boundary orientation, and the like.
According to another aspect, a method for treating an eye of a patient is provided. The method may include providing a retinal image of the patient's eye, directing a beam toward a first treatment area of the retina to provide a therapeutic treatment for the first treatment area, and superimposing indicia of the therapeutic treatment on the retinal image at a first location corresponding to the first treatment area.
According to some embodiments, the method may also include directing the beam onto at least one additional treatment area of the retina to provide the therapeutic treatment for the at least one additional treatment area and superimposing indicia of the therapeutic treatment on the retinal image at one or more locations corresponding to the at least one additional treatment area. The method may further include storing the retinal image with the super imposed indicia so as to track the treatments the patient receives. One or more additional therapeutic treatments that are to be provided to the patient may also be superimposed on the retinal image.
According to some embodiments, the method may additionally include determining a treatment boundary for the first treatment area. The treatment boundary may define a region of retinal tissue to be provided with the therapeutic treatment. In such embodiments, the method may additionally include delivering the therapeutic treatment to the first treatment area by selectively directing the beam within the treatment boundary. In some embodiments, an aiming beam may be directed on the retinal tissue to define the treatment boundary on the retinal tissue.
According to another aspect, a system for treating an eye of a patient is provided. The system may include, among other things, a treatment beam source, a scanning device, an image capture device, a display, and a processor. The treatment beam source may be configured to transmit a treatment beam along a treatment beam path. The scanning device may be disposed along the treatment beam path and may be configured to scan the treatment beam along a retina of the patient's eye. The image capture device may be oriented so as to capture an image of the retina and the display may be coupled with the image capture device. The processor may be coupled to the scanning device and the display and may be configured to: superimpose, on an image of the retina from the image capture device as shown in the display, indicia of a therapeutic treatment at a desired location of the retina, and deliver (e.g., via the treatment beam) the therapeutic treatment to the tissue of the retina at the desired location.
According to some embodiments, the processor may be further configured to: direct an aiming beam from an aiming beam source onto the desired location of the retina to define a desired treatment on the retina with reference to the indicia. According to some embodiments, the scanning device, the image capture device, and/or the processor may be disposed within an adapter device that is removably couplable with an ophthalmic imaging instrument and optically couplable with the treatment beam source.
According to some embodiments, the system may additionally include a memory device that is configured to store the retinal image with the superimposed indicia so as to track one or more treatments the patient receives. The memory device may be further configured to store an additional therapeutic treatment that is superimposing on the retinal image. The additional therapeutic treatment may be a treatment that is to be provided to the patient in a subsequent treatment. In some embodiments, superimposing an additional therapeutic treatment comprises defining, on the retinal image, a region of retinal tissue to be provided with the therapeutic treatment.
The present invention is described in conjunction with the appended figures:
In the appended figures, similar components and/or features may have the same numerical reference label. Further, various components of the same type may be distinguished by following the reference label by a letter that distinguishes among the similar components and/or features. If only the first numerical reference label is used in the specification, the description is applicable to any one of the similar components and/or features having the same first numerical reference label irrespective of the letter suffix.
The ensuing description provides exemplary embodiments only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing one or more exemplary embodiments. It should be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention as set forth in the appended claims.
Embodiments of the invention provide systems and methods for treating the retina and/or other areas of a patient's eye. The procedures may involve using one or more light beams (e.g., lasers) to cause photocoagulation to finely cauterize ocular blood vessels and/or prevent blood vessel growth to induce one or more therapeutic benefits. Such procedures may be used to treat diabetic retinopathy, macular edema, and/or other conditions of the eye. In some embodiments, photocoagulation may result in a series of visible spots that appear in the retina. In other embodiments, a series of short duration light pulses (e.g., between 5-15 microseconds) may be delivered to the retinal tissue with a thermal relaxation time delay between each pulse to limit the temperature rise of the target retinal tissue and thereby limit a thermal effect to only the retinal pigment epithelial layer. Such short duration pulses (also referred to herein as micropulses) may not result in visible spots that appear on the retina and may result in less overall tissue damage.
The treatment light (i.e., laser light) delivered to treat and/or coagulate the retinal tissue may be delivered at therapeutic levels within a defined treatment boundary that may include a pattern of recurring geometric shapes. The treatment boundary may define an area within which treatment light at therapeutic levels is directed and outside of which treatment light is substantially not directed or is provided at sub-therapeutic levels, such as in the case of refracted light, incident light, and the like. Thus, the treatment boundary may define an area within which therapeutic treatment is provided and outside of which therapeutic treatment is not provided or minimally provided. The treatment boundary and/or pattern may be projected and/or defined on the retinal surface of the patient's eye to display the area to be treated. Because the treatment boundary may define or distinguish the area of the retina that does not receive or minimally receives the therapeutic treatment, a peripheral edge of the treatment boundary may be positioned adjacent sensitive tissue of the retina and/or anywhere that the therapeutic treatment is not desired to ensure that the sensitive tissue or area will not receive or will minimally receive the therapeutic treatment. It should be realized that some therapeutic light may be incident upon tissue outside of the treatment boundary due to refraction, light scattering, and the like, but such light will be minimal and likely have minimal effect upon the tissue outside of the treatment boundary. Thus, embodiments of the invention provide precise controls for determining areas of the retina that will receive therapeutic treatment and areas that will not.
The peripheral edge of the treatment boundary, along with the remainder of the treatment boundary, may be defined and displayed on a user interface, map or image of the retina, and/or on the retina itself so that a physician or user providing the therapeutic treatment is aware of the outer boundary of the treatment area. Since the outer boundary of the treatment area is displayed, the physician may closely abut or place the treatment area proximate to sensitive tissue and/or to any other area while ensuring that the sensitive tissue or other area will not be treated or minimally treated.
In some embodiments, a treatment pattern includes an array of aiming spots instead of, or in addition to, an enclosed boundary or pattern. The array of aiming spots may be defined on the patient's retina as described herein and the treatment beam may be fired or delivered coaxially with respect to one or more of the aiming spots.
The treatment boundary and/or treatment pattern may be defined and/or projected on the retinal surface using one or more aiming beams. The aiming beam may be a laser beam or any other type of light beam (e.g., a beam produced by a high powered light emitting diode (LED)). The aiming beam may be generally referred to herein as an aiming laser, although it should be realized that light beams other than lasers may be used. The aiming beam may be a low intensity laserlight beam that does not damage the retinal tissue. In some embodiments, the aiming beam has a wavelength of between about 600 nm (nanometers) and about 700 nm, and more commonly about 650 nm. The aiming beam may be provided by a laser diode and may have an incident spot or cross section on the retinal tissue that is substantially smaller than an incident spot of the treatment laser that is used to treat the retinal tissue. Alternatively, in some embodiments, the aiming beam may be provided by a high powered light emitting diode (LED) in place of, or in addition, to the aiming laser. The aiming beam may be scanned on the patient's retina, or on a display interface or image of the retina, to trace or outline the treatment boundary and/or treatment pattern so as to visually display the treatment boundary and/or pattern to a physician. The treatment boundary and/or pattern defined or projected onto the retinal surface may be captured by a camera and displayed to the physician or other user on a display interface.
One or more treatment beam pulses or doses may be delivered within the treatment boundary and/or pattern to treat the retinal tissue. The treatment beam may be generally referred to herein as a treatment laser, although, like the aiming beam, it should be realized that other light beams may be used, such as a high intensity light beam from a high powered light emitting diode (LED). The treatment pulses or doses may be delivered as a scanning device continuously scans an axis of the treatment beam within the treatment boundary and/or may be delivered as the scanning device sequentially moves the treatment beam axis between specified locations within the treatment boundary. In embodiments involving treatment patterns having recurring geometric shapes, one or more treatment beam pulses may be delivered within some or each of the geometric shapes. In a specific embodiment, a single treatment beam pulse may be delivered substantially in a geometric center of each of the geometric shapes. A cross section of the incident beam light (e.g., a laser beam spot) may be roughly equivalent in size with the geometric shape. In some embodiments, the treatment beam (e.g., laser beam) may have a wavelength of between about 400 nm and 600 nm, and more commonly between about 520 nm and 560 nm.
The therapeutic treatment (also referred to herein as a boundary defined therapeutic treatment) may be provided via an adapter that is configured to be mounted onto and operate with a preexisting ophthalmic imaging instrument, such as a slit lamp. The adapter may also operate with a preexisting treatment beam source, such as a laser delivery instrument. An external controller or computer system may be communicatively coupled with the adapter and laser delivery instrument to define the treatment boundary and/or pattern on the retinal tissue and deliver the treatment beam within the treatment boundary/pattern. The adapter and/or controller may allow a preexisting slit lamp and laser delivery instrument to provide the boundary defined therapeutic treatment described herein, which slit lamp and laser delivery instrument would otherwise be incapable of delivering.
Embodiments of the invention also describe methods and system of using retinal imaging and/or tracking to provide a therapeutic treatment (e.g., the boundary defined therapeutic treatment) described herein or another therapeutic treatment. The therapeutic treatment and/or a treatment boundary may be programmed and/or documented with reference to a retinal image or model of a patient's retina. A system performing the therapeutic treatment may reference the retinal image or model and the programmed therapeutic treatment or treatment boundary to determine a location or area of the patient's retina to provide the therapeutic treatment. The system may then automatically begin the therapeutic treatment or display the treatment boundary/pattern and corresponding retina treatment area to a physician for review, adjustment, and/or authorization to proceed. A plurality of such therapeutic treatments may be programmed into the system so that the system may quickly and conveniently begin performing an additional therapeutic treatment shortly after completing a current or previous treatment. The provided treatments may be documented or recorded on the retinal image or model for simultaneous or subsequent review by the physician or user. For example, treatment spots or other indicia may be superimposed on the retinal image for each location or position that a pulse or dose of the treatment beam is received. The superimposed spots or indicia may document the areas of the retina for which therapeutic treatment was provided. This may be particularly useful when no visible effects of the therapeutic treatment are present on the retinal tissue, such as in micropulse procedures.
Referencing the therapeutic treatment and/or treatment boundary procedure with respect to the retinal image or model may also allow the system to compensate for movement of the patient's eye during the procedure. For example, retinal tracking may allow a camera to capture substantially smooth images of the retina and/or allow the system to adjust to a movement of the patient's eye and continue to deliver the therapeutic treatment at substantially the same location. Having briefly described some embodiments of the invention, additional aspects will become apparent with reference to the figures.
Embodiments of Therapeutic Treatment Hardware and Components
Adapter 100 further includes an interface or port 110 that couples with a fiber optic cable of an external laser delivery instrument (e.g., laser delivery instrument 310). The fiber optic cable of the external laser delivery instrument provides or delivers a treatment laser 112 to adapter 100. Adapter 100 includes mirror 136 that reflects treatment laser 112 toward an aiming device 130 (also referred to herein as a scanning device or system). Mirror 136 may be a perforated mirror, half mirror, dichroic mirror, and the like and may be mounted on a lens holder. Aiming device 130 may be a galvanometer-based scanner (commonly referred to as “galvos”) manufactured by Cambridge Technology®. Aiming device 130 includes a pair of rotatable elements or mirrors, 132 and 134, mounted atop motors that rotate elements or mirrors, 132 and 134, about orthogonal axes. Each mirror, 132 and 134, may provide 1-D beam deflection, so that the pair of mirrors provides 2-D beam deflection. Aiming device 130 is used to scan treatment laser 112 and/or other lasers (e.g., aiming laser 122) relative to the eye so that the lasers may be aimed and fired at desired locations on or within the eye. For example, aiming device 130 may be used to scan aiming laser 122 to define the treatment boundary and/or treatment pattern on retinal tissue and to scan a beam of treatment laser 112 within the treatment boundary/pattern so as to provide the boundary defined therapeutic treatment.
Aiming laser 122 passes through mirror 136 to aiming device 130. In some embodiments, adapter 100 may include another interface or port (not shown) that receives the aiming laser 122 from an external laser delivery instrument or source (not shown), which may be the same laser delivery instrument that delivers treatment laser 112 or a different unit. In other embodiments, adapter 100 includes a laser delivery instrument or source 120 within housing 102. For example, laser delivery instrument 120 may include a laser diode 124, or alternatively a high powered LED, that provides the aiming laser 122. Laser delivery instrument 120 may also include a computing device 126, such as a memory device and/or processor, that is communicatively coupled with an external controller (e.g., controller 330 and/or 310) to control the delivery of aiming laser 122.
In one embodiment, aiming laser 122 may be provided along a laser path substantially orthogonal to a laser path of treatment laser 112. The laser paths of aiming laser 122 and treatment laser 112, however, may be aligned or substantially coaxial after aiming laser 122 pass through mirror 136. For example, laser path 128 illustrates a path of a laser being delivered from aiming device 130 and reflected off mirror 106 toward an eye of a patient. Laser path 128 may correspond to either or both aiming laser 122 and treatment laser 112 since at this point the laser paths may be coaxially aligned.
Aiming laser 122 may have a wavelength selected within the visible spectrum to provide improved visibility of the treatment boundary and/or pattern on the retina. For example, in some embodiments, aiming laser 122 has a wavelength between about 600 nm and about 700 nm, and more commonly about 650 nm. Aiming laser 122 may be a low intensity beam that does not damage retinal and/or other tissue of the eye. Aiming laser 122 may also have an incident spot or cross section that is substantially smaller than an incident spot of treatment laser 112. In some embodiments, treatment laser 112 may also have a wavelength selected within the visible spectrum, although non-visible wavelengths may also be used. In a specific embodiment, treatment laser 112 has a wavelength of between about 400 nm and 600 nm, and more commonly between about 520 nm and 560 nm. Treatment laser 112 may be used to coagulate retinal and/or other tissue of the eye and/or provide other therapeutic healing.
Adapter 100 also include a magnification mechanism 140 that may be used to increase the cross section or incident spot of the treatment laser 112 and/or aiming laser 122. Magnification mechanism 140 is positioned along a laser path (e.g., laser path 128) distally of aiming device 130. Magnification mechanism 140 includes a plurality of lenses 142 mounted on a rotatable lens holder 144. Each lens has a specified optic power that increases or decreases the cross section or incident spot of the treatment laser 112 and/or aiming laser 122. Lens holder 144 may be rotated so that a desired lens is positioned along laser path 128. In some embodiments, lens holder 144 is rotated by rotating a control knob 146 positioned on an exterior surface of housing 102, although in some embodiments, lens holder 144 may be rotated electronically.
Laser delivery instrument 310 may be a conventional unit that is not able to offer the boundary defined therapeutic treatment in its conventional state. To enable the laser delivery instrument 310 to provide this treatment, a computer system 330 may be communicatively coupled with laser delivery instrument 310 and/or adapter 100. Computer system 330 may be a separate set top box that plugs into one or more ports of the laser delivery instrument 310 to communicate with laser delivery instrument 310. Additionally, computer system 330 may include one or more processors and memory devices that allow computer system 330 to interface with various other systems or units to perform the therapeutic treatment. Information may be routed between computer system 330 and a computer system or processor of laser delivery instrument 310 so that computer system 330 controls the delivery of treatment laser 112 and graphical displays information to a user via display interface 320. For example, computer system 330 may interface with the controls of laser delivery instrument 310 (e.g., touch screen controls, remote control 326, foot pedal 340, and the like) so that adjustment of the controls of laser delivery instrument 310 configure or adjust the settings and parameters of computer system 330. As shown in
In essence, computer system 330 may be communicatively coupled with laser delivery instrument 310 so that laser delivery instrument 310 functions as a pass through input and interface device for computer system 330 to enable a physician or user to interface with computer system 330 and adjust various parameters of the therapeutic treatment. Computer system 330 also functions with the preexisting controls of laser delivery instrument 310 (e.g., foot pedal 340, internal hardware components, and the like) to deliver treatment laser 112 to adapter 100.
Computer system 330 is also communicatively coupled with adapter 100 to perform various aiming or other functions. For example, computer system 330 may control aiming or scanning device 130 and/or laser delivery instrument 120 to aim or scan treatment laser 112 and aiming laser 122 onto specified areas of the retina. Computer system 330 may interleave treatment laser 112 and aiming laser 122 during the therapeutic treatment procedure. Computing device 330 controls the delivery of aiming laser 122 and controls scanning device 130 to define or project the treatment boundary or treatment pattern onto the retina.
In some embodiments, control unit 330 switches aiming laser 122 on while treatment laser 112 is switched off to define the treatment boundary. Control unit 330 then switches aiming laser 122 off while treatment laser 112 is fired at target tissue within the treatment boundary. Between subsequent firings of treatment laser 112, control unit 330 may switch aiming laser 122 on to redefine or project the treatment boundary or pattern on the retina. As shown in
Although shown as separate units, in some embodiments, laser delivery instrument 310 and computer system 330 are combined into a single unit so that substantially all the controls and operations are provided from a single unit. Further, as described in more detail below, computer system 330 may be coupled with a camera 360 (e.g., CCD camera and the like) to provide the retinal imaging and tracking features described below as well as to display the treatment boundary and/or pattern on a display device, such as display interface 320.
Computer system 330 may comprise hardware and/or software, often including one or more programmable processor units running machine readable program instructions or code for implementing some or all of one or more of the methods described herein. The code will often be embodied in a tangible media such as a memory (optionally a read only memory, a random access memory, a non-volatile memory, or the like) and/or a recording media (such as a floppy disk, a hard drive, a CD, a DVD, a memory stick, or the like).
Display 420 may be used to adjust the treatment laser 112 between traditional photocoagulating procedures and micropulse procedures. Display 420 may also include other controls 428, such as a control that selects a port (e.g., 322) to which optic fiber 324 will connect. As described above, the controls of the display 320 may be touch screen controls or may include rotatable or selectable tabs or buttons.
Embodiments of Treatment Boundaries and/or Patterns
The treatment boundaries, patterns, and/or geometric shapes may be projected or defined on the retina by controlling a position of the aiming laser (e.g., aiming laser 122) via scanning or aiming device, so that the aiming laser outlines or defines the treatment boundaries, patterns, and/or geometric shapes on retinal tissue and/or displays the treatment pattern on a display device or interface. The position of the aiming laser may be adjusted between each of a plurality of pulses to define or outline the treatment boundaries, patterns, and/or geometric shapes on the retina. The resulting visual effect may be a solid, semi-solid, or pulsing treatment boundary, pattern, and/or geometric shapes defined on the retina as shown in
It should be realized that
Although
Embodiments of Therapeutic Treatment Procedures
In some embodiments, the treatment laser may be fired substantially within a geometric center of each of the geometric shapes as is shown in
The therapeutic treatment pulses or doses (e.g., the spots shown in
In micropulse procedures, the interval between therapeutic treatment pulses or doses at the same target site may be sufficiently long so that the retinal tissue being treated sufficiently relaxes and a temperature of the tissue remains below a threshold of coagulative damage, thereby minimizing tissue damage. The thermal effect of the micropulse procedure may be confined only to the retinal pigment epithelial layer. In some embodiments, this relaxation interval, or thermal relaxation time delay, may be about 190 microseconds or longer. Likewise, in some embodiments, the firing duration of the treatment laser (i.e., the treatment pulse or dose duration) is between about 5 and 15 microsecond, and more commonly about 10 microseconds.
Each scan and firing process (i.e., between defined start and end points) may constitute a cycle of a micropulse procedure. The micropulse procedure may involve between about 10 and 10,000 cycles. In some embodiments, the treatments laser is fired at 9 or more treatment sites during each cycle of the scan and each micropulse cycle is completed in between about 0.5 and 1.5 milliseconds, and more commonly about 1 millisecond, although it should be realized that the treatment laser may be fired at any number of treatment sites and the each cycle may include a shorter or longer cycle duration. Further, a therapeutic treatment procedure for a given treatment boundary/pattern may involve a single continuous scan or several continuous scans each having different start and end points.
In an alternative embodiment, the treatment laser may be sequentially positioned at each target site and a series of micropulses may be delivered at that target site before moving to the next treatment site. Each pulse may be fired for a specified duration (e.g., between about 5 and 15 microsecond, and more commonly about 10 microseconds) and may have a sufficiently long relaxation interval (e.g., about 190 microseconds or longer) so that the retinal tissue at the treatment site sufficiently relaxes and a temperature of the tissue remains below a coagulation temperature, thereby minimizing tissue damage. The short duration pulses may be sufficient to induce or provide photoactivation of a therapeutic healing as is commonly known in micropulse procedures. The former micropulse embodiment provides the advantage of allowing the treatment laser to be fired at other treatment sites during the relaxation interval, thereby minimizing an overall treatment time.
The micropulse procedure may also include delivering the series of pulses as the treatment laser beam (i.e., the axis of the treatment laser) is continuously scanned with a specified time interval between each laser pulse or dose so as to provide a predetermined spacing between adjacent treatment spots. Such procedures may be beneficial when a treatment pattern having an array of geometric shapes, such as those shown in
A therapeutic treatment procedure may involve delivering therapeutic treatment to one area of the retina and then subsequently delivering therapeutic treatment to one or more other areas of the retina. For example, the aiming device (e.g., aiming device 130) may define a first treatment boundary or pattern on a first area of the retina and deliver therapeutic treatment within the defined first treatment boundary or pattern and then subsequently define a second treatment boundary or pattern (i.e., either the same or a different boundary/pattern) on a second area of the retina and deliver therapeutic treatment within the defined second treatment boundary or pattern. This process may be repeated as often as desired to provide the therapeutic treatment.
Embodiments of Retinal Mapping/Tracking
In some embodiments, a treatment area, boundary, and/or pattern 1020 may be referenced or tracked to the image 1000, so that a relationship between the location of the treatment area, boundary, and/or pattern 1020 and the image 1000 data can be established. The treatment area, boundary, and/or pattern 1020 may be linked to a feature or reference location 1010 on the retina 1012, which can be identified in the image 1000, such as a various veins, arteries, the optic disc, macula, retinal landmarks or features, and the like. Along with locating and/or determining the treatment area, boundary, and/or pattern 1020, the measurement device (e.g., computer system 330) may also include at least a portion of a processor system capable of calculating a set of treatment instructions to be used by a therapeutic treatment deliver system, such as adapter 100 and slit lamp 200.
The measurement device (e.g., computer system 330) and/or therapeutic treatment system (e.g., adapter 100 and slit lamp 200) can have software stored in a memory and hardware that can be used to control the taking of images and delivery of therapeutic treatment (e.g., treatment laser 112) to the patient's retina, the location or the position (optionally including translations in the x, y, and z directions and torsional rotations) of the patient's eye relative to one or more optical axes of the imaging assemblies, and the like. In exemplary embodiments, among other functions, computer system 330 (e.g., the measurement device) can be programmed to calculate treatment areas, boundaries, and/or patterns 1020 based on the image(s) taken with camera 360, and measure the offset between the patient's eye in the two images. Additionally, computer system 330 can be programmed to measure or track, effectively in real-time, the movement or position x(t), y(t), z(t), and rotational orientation of the patient's eye/retina relative to the optical axis of the laser beam (e.g., treatment laser 112 and/or aiming laser 122) so as to allow computer system 330 to register or align the desired treatment areas, boundaries, and/or patterns 1020 on the real-time position of the patient's eye.
In order to register the desired treatment areas, boundaries, and/or patterns 1020 of the patient's eye during the treatment, the images from the patient's retina taken by the camera 360 should share a common coordinate system. The common coordinate system may be based a center of the pupil or inner iris boundary, a center of the outer iris boundary, a center of various veins or arteries, a center of the optic disc or macula, a center of other retinal landmarks or features, or any other suitable feature of the eye.
As shown in
In some embodiments, the one or more desired treatment areas, boundaries, and/or patterns 1020 may then be programmed into computer system 330. Computer system 330 may operate with camera 360 to determine an area of the patient's retina 1012 that corresponds to the programmed treatment area(s) by comparing the patient's retina and retinal image 1000. In some embodiments, a second image of the eye is captured by camera 360, such as immediately prior to the therapeutic treatment procedure, and the two images are processed or compared to generate retinal treatment location information, which information may then be referenced to the second image. The treatment area(s), boundary(s), and/or pattern(s) may be superimposed on the patient's retina and/or displayed on a display interface (e.g., touch screen display 320) prior to the therapeutic treatment procedure in order to display the treatment(s) that will be provided and the areas that will receive such treatment(s). A physician or user may evaluate the treatment(s) and, if desired, modify or adjust a property (e.g., orientation, scale, boundary, pattern, and the like) of one or more of the treatments.
In some embodiments, computer system 330 may instruct adapter 100, or some component of a therapeutic treatment system, to fire an aiming laser beam (e.g., aiming laser 122) onto the determined treatment area of retina 1012 to define the treatment boundary and/or pattern 1020 on retina 1012. In other embodiments, a treatment boundary and/or pattern may not be defined on the retina and, thus, an aiming laser may not be needed.
Computer system 330 may also instruct laser delivery instrument 310, or other therapeutic treatment system component, to direct a therapeutic laser beam (e.g., treatment laser 112) onto the retina 1012 within the treatment area and/or within the treatment boundary and/or pattern 1020 defined by the aiming laser beam. The second laser beam (e.g., treatment laser 112) may deliver the desired therapeutic treatment pulses or doses 1030 (e.g., micropulse or other treatment) to retinal tissue within the defined treatment area and/or treatment boundary and/or pattern 1020 as shown in
The retinal image 1000 may be stored in a memory device and/or database for immediate or future reference. As briefly described above, the therapeutic treatments 1030 provided on the retinal tissue 1012 may be documented or recorded on the retinal image 1000 in order to track the treatment or treatments the patient receives. Documenting/recording of the therapeutic treatments provided may involve monitoring a position of the treatment laser beam 112 (i.e., a position of the laser beam axis) with respect to retinal image 1000 and recording each position of the treatment laser beam when the treatment laser 112 is fired. Individual treatment spots or locations may be recorded on retinal image 1000 to display the areas that have received treatment. Such mapping and documenting/recording procedures may be particularly useful in micropulse therapeutic treatment procedures where no visible effects of the therapeutic treatment are present and previous micropulse treatments may otherwise been unknown.
Similarly, a plurality of therapeutic treatments to provide to a patient over one or more treatment sessions may be mapped or imaged on retinal image 1000. Each therapeutic treatment subsequently provided may be documented or recorded on retinal image 1000, or a second retinal image, so that the actual therapeutic treatments provided may be compared with the therapeutic treatments mapped or imaged in order to track an overall treatment status of the patient or determine the progress of the treatments and the patient's response to such treatments.
Computer system 330 and camera 360 may also be used to adjust the therapeutic treatment system (e.g., treatment laser 112 and/or aiming laser 122) in response to movement of the patient's eye. For example, computer system 330 may reference retinal image 1000 with one or more other images provided by camera 360 to determine whether the patient's eye has moved. In response to movement of the eye, the position of the aiming laser 122 may be adjusted so that the projected or defined treatment boundary/pattern maintains a correct orientation with respect to the retina. Likewise, the position of the treatment laser 112 may also be adjusted to compensate for movement of the eye to ensure that the treatment laser 112 is fired within the adjusted treatment area, boundary, and/or pattern. The adjustment may include determining a new position of retinal features of the eye (e.g., veins, arteries, macula, and the like), determining a new position of the treatment boundary/pattern based on the new position of the retinal features, and adjusting the aiming device 130 accordingly. The images captured by camera 360 may be provided to computer system 330 and compared with retinal image 1000 in real time to provide real time tracking and adjustment of the therapeutic treatment based on movement of the eye.
Exemplary Retinal Mapping/Tracking
Described hereinbelow are methods that may be used to precisely located beam treatment positions automatically, log the treatment positions, and correctly place the treatment positions on a reference retina image. Machine vision techniques are currently available to create a retina mapping system. The retina has features (e.g., blood vessels and the like) available to serve as spatial and pattern references. These vessels and other features look different from the background because of the different properties they have relative to the background. These differences produce a contrast that may be used by machine vision algorithms. In one embodiment, the retinal imaging/mapping algorithm may perform the following functions: 1) Obtain a full retina image and determine references, treatments plans, and the like. 2) Obtain images that are synchronized with laser pulses. 3) Locate the synchronized images on the full image. 4) Display the locations of the synchronized images.
In another embodiment, the algorithm may specifically perform the following operations in a retinal imaging/mapping algorithm: 1) Locate the optic nerve to use as landmark in retinal imaging/mapping. 2) Simultaneously capture an image and a treatment/laser spot. The center of the image is typically the location of the laser spot. The illumination of the captured image may be the same wavelength as the fundus or retinal image (i.e., the “pre-treatment capture” of a full retina). The captured image may have different contrast, size, and the like. The captured image may have nearly the same magnification as the retinal image. 3) Locate the treatment spot image on a full retina image (fundus). The center of the treatment spot may be the center of the captured image. In some embodiments, the precision may range from about 1 μm to about 10 μm with an average precision of about 3 μm, however, the system may be optimized to increase precision. Optimizing the system may include: optical distortion reduction or compensation and/or tightening optic nerve matching criteria.
Full Retinal Image and Optic Never Region of Interest Pre-Treatment
Because the optic nerve region has high feature content, pattern matching its location may be relatively easy. Consider the fundus image shown in
Calibration
An image captured during each treatment shot may be synchronized and/or timed stamped to the pulse. Since the treatment spot within a captured sub-image, or slit, may be “predetermined” at calibration, the location of the treatment spot relative to the slit image and its relationship to the treatment map is typically known. Sequentially repeating this process for multiple sub-images (slits) images will produce a post treatment map.
Slit Image Location Mapping Technique
As an example of the slit image location mapping technique, seven slit images were obtained from seven different retina images and matched onto a single reference retinal image. The seven slit images were cropped from the seven full retina images. Shown in
The slit images were passed or provided to the pattern matching algorithm, which was used to locate the positions on a random full retinal image.
Testing the Precision of the Algorithm's Locate Function
Relative measurements of the distance from the optic nerve to the slit images demonstrate the precision of the matching algorithm. The optic nerve typically functions as the reference point used by the algorithm, a treatment planner, the treatment itself, and/or post-precision analysis. The distances from the center of a respective slit image and the center of the optic nerve was calculated as shown by the X,Y coordinates in
Original(x,y)=slit center(x,y)−optic nerve(x,y)
Patterned matched(x,y)=slit center on reference image(x,y)−optic nerve(x,y)
Table 1 below displays the results of the measurements.
As stated above, a perfect match will produce a delta of zero. Each pixel is approximately 10 μm so the largest error is approximately 0.1 mm (i.e., delta 10, line 5 in table 1). The errors illustrated above could be reduced by optimizing the algorithm. The algorithm detected all seven rectangles in less than one second.
Treatment Planner
A treatment planner takes physician pre-determined treatment positions on the retinal images and treats these locations on the actual retina. A scanner is typically required for this to work. Possible algorithms that may be used include: 1) providing the treatment in coordinates relative to the optic nerve, and/or 2) using active pattern matching to locate the treatment spot on the retina. Algorithm 1 may require less image processing but require a large scanner dynamic range while algorithm 2 may require more image processing power.
Additional Image Processing Ideas
In some embodiments, it may be beneficial to pre-process the retinal images prior to detection. For example, thresholding after image leveling may provide good vessels or other feature discrimination for both dark and light field images. The following images had the following operations done to them. In some embodiments, the hardware that implements the above algorithms may be “piggy backed” onto or otherwise coupled with an existing slit lamp. In other embodiments, a user friendly standalone device may be integrated with a table top model. A self-contained refractometer may be used as a possible platform to begin design of a cartography system. Though not designed specifically for retina imaging, modern refractometers typically have imaging optics to view and capture digital images of the anterior and posterior segments. These devices may not need special cameras, but rather may use standard NTSC or PAL cameras. The choice of cameras may depend on the illumination wavelength.
The system may be a treatment planning, treatment, and treatment analysis platform. In some embodiments, imaging cameras may share optical paths with the physician view. The images may be captured in sync with the laser pulses. The device may display the treatment spots on the display in real time or display them post treatment to reduce costs or for various other reasons. All treatment information may be is saved and post processed to calculate dosimetry. In some embodiments, the same software may be used to plan the treatment and analyze efficacy.
In some embodiments, rather than sending a beam with treatment intensity, a diagnostic tool may send a “vision” beam to a specific location and the patient asked if he or she is able to see the beam. The diagnostic tool may know the location of the beam and a positive answer may imply that the retina area is active. In some embodiments, the efficiency of a pattern matching algorithm may depend on the quality of the images. The images used in this analysis generally have very good contrast and are in good focus. Pattern matching algorithms typically have an easier time locating objects when clean high frequency information is available. Similarly, the tracking precision may be related to the spatial content so some form of auto focus is generally recommended. Tracking with low frequency content images can be done, but at a lower resolution by tracking large objects within the field.
Having described several embodiments, it will be recognized by those of skill in the art that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the invention. Additionally, a number of well-known processes and elements have not been described in order to avoid unnecessarily obscuring the present invention. Accordingly, the above description should not be taken as limiting the scope of the invention.
Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limits of that range is also specifically disclosed. Each smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in that stated range is encompassed. The upper and lower limits of these smaller ranges may independently be included or excluded in the range, and each range where either, neither or both limits are included in the smaller ranges is also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included.
As used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a process” includes a plurality of such processes and reference to “the device” includes reference to one or more devices and equivalents thereof known to those skilled in the art, and so forth.
Also, the words “comprise,” “comprising,” “include,” “including,” and “includes” when used in this specification and in the following claims are intended to specify the presence of stated features, integers, components, or steps, but they do not preclude the presence or addition of one or more other features, integers, components, steps, acts, or groups.
This application claims priority to Provisional U.S. Patent Application No. 61/549,036 filed Oct. 19, 2011, entitled “Grid Pattern Therapeutic Treatment,” the entire disclosure of which is hereby incorporated by reference, for all purposes, as if fully set forth herein.
| Number | Date | Country | |
|---|---|---|---|
| 61549036 | Oct 2011 | US |
