Psychophysical assessment of impact of vitreous floats

Abstract

Particular embodiments disclosed herein enable psychophysical assessment of vitreous floats (114). One or more patient stimulation images (600, 916) are projected onto a retina (112) of a patient, the patient stimulation images (600, 916) comprising a stationary or moving gaze target (602). While displaying a patient stimulation image (600, 916), an image (200) of a patient retina (112) is captured, such as using a SLO (402), and a shadow image (204) is derived from the image (200). The shadow image (204) includes a representation of a shadow (206) projected by the float (114). An observer stimulation image (918) is generated from the shadow image (204) and the patient stimulation image (600, 916), and projected onto the retina (112) of the observer, such as using a virtual reality display device (406).

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 388,896, filed on July 13, 2022, the entire contents of which are incorporated herein by reference in their entirety. Background Art

[0003] Light enters the human eye through the clear cornea, which covers the iris and pupil of the eye. The light travels through the pupil and is focused by the lens, which is located behind the pupil in a structure called the capsular bag. The light is focused by the lens onto the retina, which consists of rods and cones, which generate nerve impulses in response to light. The space between the lens and the retina is occupied by a clear gel called the vitreous body.

[0004] Floaters may appear in the vitreous for a variety of reasons. Floaters are usually composed of clumps of cells or other tissue and are more opaque than the surrounding vitreous. Floaters can cast shadows on the retina, causing visual disturbances that can be severe for some patients.

[0005] Facilitating the treatment of floaters would be an advancement in this field. Summary of the invention

[0006] The present disclosure generally relates to a system for psychophysical assessment of vitreous floaters.

[0007] Certain embodiments disclosed herein provide a method and corresponding apparatus, the method comprising receiving, by a computing device, one or more images of at least one eye of a patient, identifying one or more shadow regions in the one or more images to obtain one or more shadow images, and outputting, by the computing device, one or more observer stimulus images derived from the one or more shadow images to a display device.

[0008] The following description and the associated drawings set forth in detail certain illustrative features of the one or more embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Certain aspects of one or more embodiments are depicted in the accompanying drawings, and therefore should not be considered to limit the scope of the disclosure.

[0010] Figure 1 is a schematic cross-sectional view of an eye with floaters.

[0011] Figure 2A It is a retinal image with shadows created by vitreous floaters.

[0012] Figure 2Bis an image of vitreous floater shadows extracted from a retinal image according to certain embodiments.

[0013] Figure 3 is a process flow diagram of a method for psychophysical assessment of vitreous floaters, according to certain embodiments.

[0014] Figure 4 is a schematic block diagram of components for psychophysical assessment of vitreous floaters, according to certain embodiments.

[0015] Figure 5 is a process flow diagram of a method for psychophysical assessment of vitreous floaters using a virtual reality display, according to certain embodiments.

[0016] Figure 6 is an example stimulus image according to some embodiments.

[0017] Figure 7 is an example stimulus image with random gaze point movement in accordance with some embodiments.

[0018] Figure 8 is an example of a stimulus image with gaze point movement that simulates eye movement while reading, according to some embodiments.

[0019] Fig. 9 An example computing device is shown that at least partially implements one or more functions of psychophysical assessment of vitreous floaters in accordance with certain embodiments.

[0020] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. DETAILED DESCRIPTION

[0021] refer to Figure 1 , the human eye 100 includes a cornea 102, which is a spherical transparent layer through which light enters the eye 100. The light then passes through the anterior chamber 138, pupil 104, and lens 106 of the eye 100, respectively. The remaining volume of the eyeball 108 of the eye 100 (called the posterior chamber or vitreous cavity 140) is occupied by a transparent gel called vitreous 110. The light is focused by the cornea 102 and lens 106, and reaches the retina 112 at the back of the eye 100 through the vitreous 110.

[0022] Vitreous floaters 114 are clumps of cells, collagen fibers, or other contaminants within the vitreous 110. When vitreous floaters 114 are present, they cast a shadow 116 on the retina 112. The shadow 116 may occupy a certain angular range of the field of view of the eye 100. When the floaters 114 are large enough, opaque, and / or numerous enough, they can significantly interfere with the patient's vision.

[0023] refer to Figure 2A , an image 200 of the retina 112 may be obtained, such as using a scanning laser ophthalmoscope (SLO), a fundus camera, an optical coherence tomography (OCT) device, or other imaging modality. A portion of the light transmitted to the retina 112 to capture the image 200 will be scattered by any floaters 114 in the vitreous body 110, resulting in one or more shadows 202 appearing in the image 200.

[0024] The one or more shadows 202 may be identified as having contrasting pixel intensities relative to the area surrounding the shadows 202. The floaters 114 tend to move, such that the one or more shadows 202 may be identified in the image 200 as having different intensities relative to the intensities of the shadows 202 in previous or subsequent images in the series of video images that includes the image 200. For example, each image in the series of images may be registered relative to a reference feature of the retina, such as the pattern of the vasculature (e.g., veins) of the retina, to compensate for eye motion. In such an example, changes from one registered image to another registered image may therefore correspond to changes in the shadows 116 of the floaters 114. The one or more shadows 202 may be identified using any method for detecting moving objects relative to a stationary background, wherein eye motion compensation is performed in the same manner as such methods are used to compensate for camera motion. Still or video images 200 may also be analyzed using a machine learning model trained to identify the one or more shadows 202 corresponding to the floaters 114.

[0025] Reference now Figure 2B , a shadow image 204 may be generated that includes only one or more shadows 206 extracted from the image 200 and corresponding to the one or more shadows 202 present in the image 200. The shadow image 204 may be an image in which all pixels except for the pixels representing the one or more shadows 202 are white, transparent, or some other reference color. The pixels of the one or more shadows 206 may have intensities that indicate an estimated degree of light blockage at the corresponding point in the shadow image 204. For example, when all pixels except for the pixels of the one or more shadows 206 in the shadow image 204 are white, the difference between the intensity of the white pixels and the intensity of a given pixel of the one or more shadows 206 indicates the darkness of the (multiple) shadows 202 represented by the given pixel of the one or more shadows 206.

[0026] Figure 3 A method 300 for psychophysical assessment of vitreous floaters is presented. As used herein, "psychophysical assessment" refers to a process that enables an observer (such as a trained medical professional) to accurately perceive the shadows 116 cast by floaters 114 onto a patient's retina 112 to determine the effect of the floaters 114 on the patient's vision.

[0027] In method 300, the patient's retina 112 is first stimulated in step 302, and the patient's visual perception of the stimulus is detected in step 304. In step 306, an observer receives a stimulus that is substantially identical to the stimulus of the patient's retina 112, which is a combination of the stimulus input to the patient's eye and the patient's perception of the stimulus detected in step 304. In step 308, the observer visually perceives 308 the observer stimulus from step 306, so that substantially identical perception between the patient and the observer is achieved in step 310.

[0028] Figure 4 A system 400 for psychophysical assessment of vitreous floaters is shown. The system 400 may include a scanning laser ophthalmoscope (SLO) 402 for stimulating and observing the retina 112 of a patient 404. The system 400 also includes a display device 406 for projecting the stimulus of the observer onto the retina of an observer 408. For example, the display device 406 may be a virtual reality (VR) display capable of projecting an image of the patient's right retina onto the observer's right retina using the right side of the VR display, and projecting an image of the patient's left retina onto the observer's left retina using the left side of the VR display.

[0029] System 400 includes a patient stimulus generator 410, an image capture module 412, and an observer stimulus generator 414, each of which may be implemented on a separate computing device (e.g., as described below with respect to Fig. 9 406), or may be implemented using computing capabilities integrated into one or both of the SLO 402 and the display device 406.

[0030] The patient stimulus generator 410 generates patient stimulus images for projection onto the patient's retina 112. The patient stimulus images may have a known brightness and include a fixation target. In some embodiments, the patient stimulus generator 410 may generate a series of images in which the fixation target is located at a different position in each image of the series of images, thereby providing a moving fixation target. One or more patient stimulus images may include a shape (e.g., a square, rectangle, or circle) of uniform color and brightness, or may be a more detailed image, such as an image of an indoor or outdoor environment, an image including text, or other types of images. The patient stimulus generator 410 may use the existing capabilities of the SLO 402 to display one or more stimulus images, or may use one or more separate projection devices to project one or more patient stimulus images onto the patient's retina 112.

[0031] The image capture module 412 can capture images of the patient's retina 112 during stimulation using one or more patient stimulation images projected by the patient stimulation generator 410. The image capture module 412 can receive images from the SLO 402 (which can generate images by scanning the patient's retina 112 using an infrared laser). The image capture module 412 can further separate the shadow 202 from the one or more images 200 received from the SLO 402 to obtain one or more shadow images 204 as described above.

[0032] The observer stimulus generator 414 generates one or more observer stimulus images from the one or more shadow images 204. The observer stimulus generator 414 may adjust some or all of the size, brightness, contrast, or other characteristics of the one or more shadow images 204 to obtain the one or more observer stimulus images. The adjustments performed by the observer stimulus generator 414 may be predefined adjustments based on the characteristics of the display device 406 to more closely approximate the viewing experience of the patient 404. For example, the size, brightness, contrast, or other characteristics may be adjusted to be within at least five percent of those characteristics perceived by the patient.

[0033] The observer stimulus images may then be displayed to an observer 408 on a display device 406. When multiple patient stimulus images are captured, the observer stimulus images may be displayed at the same frame rate at which the patient stimulus images are captured. The display of one or more observer stimulus images may be substantially simultaneous with the capture of the images 200, i.e., subject to processing and data transmission delays. Alternatively, the one or more observer stimulus images or any images used to obtain the one or more observer stimulus images may be stored for later display or processed and displayed.

[0034] Figure 5A method 500 for performing a psychophysical assessment of vitreous floaters is presented. The method 500 may be performed by a computing device 900 and a Figure 4 The SLO 402 and display device 406 shown cooperate to perform. The method 500 includes presenting one or more patient stimulation images to the patient's retina 112 in step 502. In step 504, the patient is instructed to fixate on a fixation target in the one or more patient stimulation images. While presenting the one or more patient stimulation images, the method 500 includes recording one or more images 200 of the patient's retina using the SLO 402 in step 506. For example, for each patient stimulation image, the image 200 of each retina 112 can be captured using the SLO 402 while each patient stimulation image is projected onto the patient's retina 112.

[0035] The method 500 includes extracting one or more shadow images (e.g., image 204) from one or more images 200 received from the SLO 402 at step 508. The method 500 may further include adjusting the one or more shadow images to obtain one or more adjusted images at step 510. The one or more adjusted images may then be used to generate an observer stimulus image at step 512.

[0036] Adjusting the one or more shadow images may include adjusting the brightness, contrast, size, or other characteristics of the one or more shadow images so that when displayed on the display device 406, the one or more adjusted images will closely approximate the patient's visual perception to the observer. Generating the observer stimulus images may include combining each adjusted image with a corresponding patient stimulus image, which may also be adjusted in brightness, contrast, size, or other characteristics to ensure a similar perception when displayed on the display device 406. In some embodiments, the one or more shadow images will capture only the shadow 202, so that the one or more patient stimulus images, or adjusted versions thereof, will be combined with the one or more adjusted images to replicate the patient's perception of the one or more patient stimulus images. The patient stimulus image corresponding to the adjusted image may be the patient stimulus image displayed when the image 200 was captured, which was adjusted to obtain the adjusted image.

[0037] Then, the method 500 may include displaying the one or more observer stimulation images on the display device 406 in step 514. When the one or more observer stimulation images include a plurality of observer stimulation images, the observer stimulation images may be displayed at the same frame rate as the patient stimulation images are displayed to the patient, or at a different frame rate.

[0038] Figure 6 , Figure 7 and Figure 8Example patient stimulus images are shown. As described above, the corresponding observer stimulus image may have the same features as the shadow image superimposed on it.

[0039] Figure 6 A first example patient stimulation image 600 is shown. In some embodiments, the patient stimulation image 600 has a width and height that occupies between 6 and 14 degrees, between 8 and 12 degrees, or 10 degrees of the patient's field of view. The patient stimulation image 600 includes a stationary fixation target 602, which can be in the form of a crosshair or other image visible to the patient. The patient stimulation image 600 can include a bright uniform background 604 that occupies a majority (e.g., at least 90% or at least 95%) of the patient stimulation image 600. If floaters 114 are present, the uniform background may have a brightness sufficient to produce a perceptible shadow 116 when displayed to the patient. However, the brightness is preferably not so great that the shadow 116 becomes faded and unperceptible. Similarly, the brightness is preferably not so great that it causes discomfort or retinal damage to the patient. For example, the brightness can be between about 250 and about 350 cd / m 2 (cd / m2), for example, about 300cd / m 2 .

[0040] A grid 606 may be included in the patient stimulation image 600 to facilitate determining the direction and degree of movement of shadows in the stimulation image for one or more observers. For example, the grid 606 may divide each dimension (vertical and horizontal) of the patient stimulation image 600 into three to ten segments, such as the three lines in each dimension shown dividing the patient stimulation image 600 into four segments in each dimension.

[0041] refer to Figure 7 In some embodiments, a series of patient stimulation images 600 are presented at a predefined frame rate. In the series of patient stimulation images 600, the fixation target 602 may be located at a plurality of different positions. For example, the numbers 1 to 10 shown represent the positions of the fixation target 602 in images 1 to 10 of the series of patient stimulation images 600. The offset between consecutive pairs of numbers and the frame rate at which the patient stimulation images are presented will cause the patient's eye to reach a certain angular velocity when tracking the fixation target 602. The angular velocity may be selected to simulate a typical saccadic motion of the eye.

[0042] The saccadic motion of the eye 100 causes the shadow 116 to move. When the gaze of the eye 100 is fixed, the shadows 116 and 202 usually move slowly within one to two seconds. The settling time depends on the viscosity of the vitreous 110. The vitreous of the eye decreases with age. The stable position of the floater shadow can be called the home position of the shadow. The home position of the floater 114 and the floater shadows 116 and 202 usually does not change for several months. The movement of the shadow may cause one or more floater shadows 116 and 202 to pass through the fovea of ​​the eye. The floater shadows 116 and 202 are not particularly annoying or noticeable when not moving, but may become so when moving. Therefore, the position and offset of the fixation target position in the series of images 600 can be selected to induce a series of motions in terms of angular velocity and direction, so that the impact of the floater shadows 116 and 202 in the patient's eye 100 can be accurately assessed.

[0043] Reference now Figure 8 In some embodiments, the movement of the fixation target 602 between adjacent images in a series of patient stimulus images 600 is selected to cause the patient's eye 100 to mimic the movement of the eye 100 when reading. In this way, the effect of the floater 114 on common activities (such as reading) can be evaluated. For example, the position of the fixation target 602 in the series of patient stimulus images 600 can traverse a horizontal path 800 from left to right at an angular velocity 802 (e.g., between 5 and 15 degrees per second) to simulate the movement of the eye when reading a line of text. The path 800 can be followed by a diagonal path 804 that moves downward and from right to left at a speed 806 greater than the speed 802 to simulate the movement of the eye focusing on the beginning of the next line of text. For example, the path 804 can travel at an angular velocity 806 between 80 and 120 degrees per second. Two, three, or more groups of paths 800, 804 (e.g., five groups shown) can be combined to simulate the range of movement of the patient's eye 100 when reading.

[0044] Other motion patterns of fixation target 602 may be used to simulate various languages. For example, for Hebrew, Arabic, or other Semitic languages, path 800 may be from right to left, while diagonal path 804 may be from left to right and downward. In another example, for Japanese and some forms of Mandarin, path 800 is from top to bottom, while diagonal path 804 is from bottom to top and right.

[0045] Fig. 9 Demonstrates at least partial implementation of the invention Figures 1 to 8 An example computing system 900 that can perform one or more of the functions described. The computing system 900 can be integrated with an imaging device such as SLO 402, a display device 406 such as a VR display, or can be a separate computing device that receives an image of the patient's eye from the imaging device.

[0046] As shown, the computing system 900 includes a central processing unit (CPU) 902, one or more I / O device interfaces 904 that can allow various I / O devices 914 (e.g., keyboard, display, mouse device, pen input, etc.) to be connected to the computing system 900, a network interface 906 through which the computing system 900 is connected to a network 990, a memory 908, a storage device 910, and an interconnect 912.

[0047] Where computing system 900 is an imaging system, such as SLO 402, computing system 900 may further include one or more optical components for obtaining ophthalmic imaging of a patient's eye, as well as any other components known to one of ordinary skill in the art.

[0048] CPU 902 may retrieve and execute programming instructions stored in memory 908. Similarly, CPU 902 may retrieve and store application data residing in memory 908. Interconnect 912 transfers programming instructions and application data between CPU 902, I / O device interface 904, network interface 906, memory 908, and storage device 910. CPU 902 is included to represent a single CPU, multiple CPUs, a single CPU with multiple processing cores, etc.

[0049] The memory 908 represents a volatile memory such as a random access memory and / or a non-volatile memory such as a non-volatile random access memory, a phase change random access memory, etc. As shown, the memory 908 may store the patient stimulation generator 410 , the image capture module 412 , and / or the observer stimulation generator 414 .

[0050] The storage device 910 may be a non-volatile memory such as a disk drive, a solid state drive, or a collection of storage devices distributed across multiple storage systems. The storage device 910 may optionally store patient stimulation images 916 and may also store observer stimulation images 918 for subsequent display.

[0051] Additional considerations

[0052] The foregoing description is provided to enable any person skilled in the art to practice the various embodiments described herein. Various modifications to these embodiments are clear to those skilled in the art, and the general principles defined herein may be applied to other embodiments. For example, without departing from the scope of the present disclosure, the function and arrangement of the elements discussed may be changed. Various examples may appropriately omit, replace or add various programs or components. In addition, the features described with respect to some examples may be combined in some other examples. For example, any number of aspects set forth herein may be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover devices or methods practiced using other structures, functions, or structures and functions in addition to or different from the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the present disclosure disclosed herein may be embodied by one or more elements of the claims.

[0053] As used herein, the phrase "at least one of" a list of items refers to any combination of those items, including single members. For example, "at least one of a, b, or c" is intended to cover any combination of a, b, c, ab, ac, bc, and abc, as well as multiples of the same element (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc or any other order of a, b, and c).

[0054] As used herein, the term "determining" encompasses a wide variety of actions. For example, "determining" may include calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, database, or other data structure), ascertaining, etc. Also, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), etc. Also, "determining" may include resolving, selecting, choosing, establishing, etc.

[0055] The method disclosed herein includes one or more steps or actions for implementing the method. Without departing from the scope of the claims, the method steps and / or actions can be interchangeable with each other. In other words, unless a specific step or action sequence is specified, the order and / or use of specific steps and / or actions can be modified without departing from the scope of the claims. Further, the various operations of the above-mentioned method can be performed by any suitable device that can perform the corresponding function. These devices may include various hardware and / or software components and / or modules, including but not limited to circuits, application specific integrated circuits (ASICs) or processors. Generally, in the case of operations shown in the figure, those operations can have corresponding corresponding devices with similar numbers plus functional components.

[0056] The various illustrative logical blocks, modules, and circuits described in conjunction with the present disclosure may be implemented or executed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0057] The processing system can be implemented with a bus architecture. Depending on the specific application and overall design constraints of the processing system, the bus may include any number of interconnecting buses and bridges. The bus may link together various circuits including a processor, a machine-readable medium, and an input / output device. A user interface (e.g., a keyboard, a display, a mouse, a joystick, etc.) may also be connected to the bus. The bus may also link various other circuits such as timing sources, peripherals, voltage regulators, power management circuits, etc., which are well known in the art and therefore will not be described further. The processor may be implemented with one or more general and / or special processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuit systems that can execute software. Those skilled in the art will recognize how to best implement the described functions of the processing system according to the specific application and the overall design constraints imposed on the entire system.

[0058] If implemented in software, the function may be stored as one or more instructions or codes on a computer-readable medium or transmitted via a computer-readable medium. Software should be broadly interpreted as instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or other. Computer-readable media include both computer storage media and communication media (such as any medium that facilitates the transfer of computer programs from one place to another). The processor may be responsible for managing the bus and general processing, including the execution of software modules stored on a computer-readable storage medium. A computer-readable storage medium may be coupled to a processor so that the processor can read information from the storage medium and write information to the storage medium. In an alternative, the storage medium may be integrated with the processor. For example, a computer-readable medium may include a transmission line, a carrier modulated by data, and / or a computer-readable storage medium on which instructions separated from a wireless node are stored, all of which may be accessed by a processor via a bus interface. Alternatively or in addition, a computer-readable medium or any portion thereof may be integrated into a processor, such as a cache and / or a general register file. For example, examples of machine-readable storage media may include RAM (random access memory), flash memory, ROM (read-only memory), PROM (programmable read-only memory), EPROM (erasable programmable read-only memory), EEPROM (electrically erasable programmable read-only memory), registers, magnetic disks, optical disks, hard drives, or any other suitable storage media, or any combination thereof. Machine-readable media may be embodied in a computer program product.

[0059] A software module may include a single instruction or multiple instructions, and may be distributed over several different code segments, between different programs, and across multiple storage media. A computer-readable medium may include multiple software modules. A software module includes instructions that, when executed by a device such as a processor, cause a processing system to perform various functions. A software module may include a transmission module and a reception module. Each software module may exist in a single storage device, or may be distributed across multiple storage devices. For example, when a triggering event occurs, a software module may be loaded from a hard drive into a RAM. During the execution of a software module, a processor may load some instructions into a cache to increase access speed. Then, one or more cache lines may be loaded into a general register file for execution by the processor. When referring to the function of a software module, it should be understood that such function is implemented by the processor when executing instructions from the software module.

[0060] The following claims are not intended to be limited to the embodiments shown herein, but are given the full scope consistent with the language of the claims. In the claims, unless otherwise specified, reference to a singular element is not intended to mean "one and only one", but "one or more". Unless otherwise specifically stated, the term "some" refers to one or more. According to 35 U.S.C. § 112 (f), the elements of any claim will not be interpreted unless the phrase "device for..." is used to expressly describe these elements, or in the case of a method claim, the phrase "step for..." is used to describe these elements. All structural and functional equivalents of the elements of the various aspects described throughout this disclosure that are known or will be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be covered by the claims. In addition, whether or not such disclosure is explicitly described in the claims, the content disclosed herein is not intended to be committed to the public.

Claims

1. A system for characterizing floating objects, the system comprising: Retinal imaging devices; Display devices; as well as A computing device, the computing device being configured to: receiving one or more images of at least one patient's retina from the retinal imaging device; identifying one or more shadow regions in the one or more images to obtain one or more shadow images; as well as One or more observer stimulus images are output to a display device, the one or more observer stimulus images being derived from the one or more shadow images.

2. The system of claim 1, wherein: The retinal imaging device is a scanning laser ophthalmoscope.

3. The system of claim 1, wherein: The computing device is further configured to stimulate the at least one patient retina with one or more patient stimulation images while capturing the one or more images of the at least one patient retina.

4. The system of claim 3, wherein: The one or more patient stimulation images each include a fixation target.

5. The system of claim 4, wherein: The one or more patient stimulation images include a series of patient stimulation images, wherein the fixation targets of the series of patient stimulation images are located at a plurality of different positions.

6. The system of claim 5, wherein: The multiple different positions simulate eye movements while reading.

7. The system of claim 3, wherein: The computing device is further configured to derive the one or more observer stimulation images from the one or more shadow images by combining the one or more shadow images with the one or more patient stimulation images.

8. The system of claim 1, wherein: The computing device is further configured to derive the one or more observer stimulus images from the one or more shadow images by adjusting one or both of a size and a brightness of the one or more shadow images based on characteristics of the display device.

9. The system of claim 1, wherein: The display device is a virtual reality display device.

10. The system of claim 9, wherein: The one or more images of the at least one patient's retina include one or more left images of the patient's left retina and one or more right images of the patient's right retina; Wherein, the computing device is configured to output the one or more observer stimulus images derived from the one or more shadow images to the display device in the following manner: outputting one or more left observer stimulation images of the one or more observer stimulation images on the left side of the virtual reality display device, the one or more left observer stimulation images being derived from the one or more left images; and One or more right observer stimulation images of the one or more observer stimulation images are outputted on the right side of the virtual reality display device, the one or more right observer stimulation images being derived from the one or more right images.

Images