WO2020139192A1

WO2020139192A1 - System, method and apparatus for detecting an eye condition

Info

Publication number: WO2020139192A1
Application number: PCT/SG2019/050542
Authority: WO
Inventors: Wei Leon Leonard YIP
Original assignee: Tan Tock Seng Hospital Pte Ltd
Current assignee: Tan Tock Seng Hospital Pte Ltd
Priority date: 2018-12-27
Filing date: 2019-11-06
Publication date: 2020-07-02
Anticipated expiration: 2021-06-27
Also published as: SG11202010214PA

Abstract

Disclosed is a system for detecting an eye condition comprising a processor arranged in signal communication with a user interface device; the user interface device for displaying a visual field test and configured to receive a user input in relation to an abnormal region associated with the visual field test; wherein the processor is configured to receive data associated with the abnormal region to provide a measurement of an eye condition. In particular, the visual field test comprises a first set of test images for detecting the presence of a visual field defect and a second set of test images for detecting the severity of the visual field defect.

Description

SYSTEM, METHOD AND APPARATUS FOR DETECTING AN EYE

CONDITION

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the priority to Singapore application No.

1020181 1672V, filed 27 December 2018, the contents of which are incorporated herein by reference.

FIELD

[0002] The present disclosure relates generally to a system, method and apparatus for detecting an eye condition, such as, but not limited to, glaucoma.

BACKGROUND

[0003] The following discussion of the background to the invention is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge of the person skilled in the art in any jurisdiction as at the priority date of the invention.

[0004] Glaucoma is one of the leading causes of blindness and visual impairment around the World. Diagnosis of Glaucoma typically requires visual field (VF) testing to detect VF defects.

[0005] In current clinical practice, a typical method of detecting visual field defects is by using standard automated perimetry. The Flumphrey Visual Field (FIVF) machine (see Figure 1 ) is commonly used to test for visual field loss. In tests involving the FIVF machine, each eye is tested separately and about 76 different locations (test points) are tested. Repeated testing at each location may be required.

[0006] It is to be appreciated that FIVF uses a coarse approach, whereby standard test points are scattered throughout a test screen and are of a certain distance from each other. The individual being tested is required to use a clicker to indicate whenever a light appears at a test point. Each test point may also be re-calibrated to determine the dimmest light visible there. The machine will then map out the scores at every test location of a test subject (e.g. the individual’s) eye.

[0007] The HVF method is however time consuming; it can take up to approximately 10 minutes per eye and greatly relies on the patient’s concentration during testing. There is a higher likelihood of getting inaccurate results in glaucoma patients, as they may not be able to keep their eyes looking in a single direction (i.e. a test point) for an extended period of time due to the disease. In addition, HVF machines are non-portable, take up a considerable amount of space and are expensive. Hence, hospitals may not be able to place many machines within a clinic, due to cost and space constraints.

[0008] Individuals with suspected visual field defects and glaucomatous changes are sent to perform HVF testing. This results in frequent overbooking of test sessions due to the inadequate supply of resources.

[0009] There exists a need to avail visual field tests to more individuals and alleviate at least one of the aforementioned problems.

SUMMARY

[0010] A system, method and/or apparatus for detecting an eye condition is envisaged.

[0011] Accordingly, an aspect of the invention refers to a system comprising a processor arranged in signal communication with a user interface device; the user interface device for displaying a visual field test and configured to receive a user input in relation to an abnormal region associated with the visual field test; wherein the processor is configured to receive data associated with the abnormal region to provide a measurement of an eye condition. [0012] In some embodiments, the user interface device includes a mobile computer device.

[0013] In some embodiments, the mobile computer device is a mobile phone or a tablet PC. [0014] In some embodiments, the visual field test includes a plurality of images provided to a user via the user interface device.

[0015] In some embodiments, the visual field test comprises a first set of test images for detecting the presence of a visual field defect and a second set of test images for detecting the extent or severity of the visual field defect.

[0016] In some embodiments, the second set of test images is dependent on the user input provided by the user in relation to the first set of test images.

[0017] According to another aspect there is a method for detecting an eye condition comprising displaying on a user interface a first set of visual field test images for input by a user; detecting a user input in relation to an abnormal region associated with the first set of visual field test images; wherein when an abnormal region is detected, the method further displays a second set of test images for detecting the extent or severity of the visual field defect.

[0018] According to another aspect there is a non-transitory computer readable medium containing executable software instructions thereon wherein when executed performs a method for detecting an eye condition, the method comprises the steps of: displaying on a user interface a first set of visual field test images for input by a user; detecting a user input in relation to an abnormal region associated with the first set of visual field test images; wherein when an abnormal region is detected, the method further displays a second set of test images for detecting the extent or severity of the visual field defect.

[0019] According to another aspect there is an apparatus for detecting an eye condition including a processor module arranged in signal communication with a user interface module; the user interface module configured to display a visual field test and configured to detect a user input in relation to an abnormal region associated with the visual field test; wherein the processor module is configured to calculate a measurement of an eye condition based on the detected user input.

[0020] In some embodiments, the user input is in the form of an area demarcated by a user. [0021] In some embodiments, if no user input is detected the measurement of the eye condition is regarded as normal.

BRIEF DESCRIPTION OF THE DRAWINGS [0022] In the figures, which illustrate, by way of non-limiting examples only, embodiments of the present invention,

[0023] Figure 1 : shows a prior art HVF machine for testing of an eye condition such as Glaucoma;

[0024] Figure 2: shows a system diagram for detecting an eye condition according to some embodiments;

[0025] Figure 3: show possible images that are used in visual field tests in accordance with some embodiments;

[0026] Figure 4: shows an example where an area on an image used for visual field tests was marked by a user to be abnormal; [0027] Figure 5: shows an exemplary test result display on the interface;

[0028] Figure 6: shows an embodiment where a selected abnormal region can be used for further testing and evaluation; and

[0029] Figure 7: is a table comparing the prior art system with envisaged system and method for detecting an eye condition such as Glaucoma. DETAILED DESCRIPTION

[0030] Throughout this document, unless otherwise indicated to the contrary, the terms“comprising”,“consisting of”,“having” and the like, are to be construed as non- exhaustive, or in other words, as meaning“including, but not limited to”.

[0031] Furthermore, throughout the document, unless the context requires otherwise, the word“include” or variations such as“includes” or“including” will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. [0032] Throughout the description, it is to be appreciated that the term‘processor’ and its plural form include microcontrollers, microprocessors, programmable integrated circuit chips such as application specific integrated circuit chip (ASIC), computer servers, electronic devices, and/or combination thereof capable of processing one or more input electronic signals to produce one or more output electronic signals.

[0033] Throughout the description, it is to be appreciated that the term‘server’ and its plural form can include local, distributed servers, and combinations of both local and distributed servers. [0034] Throughout the description, it is to be appreciated that the term‘channel’ or‘channels’ include wired or wireless electronic communication channels. The wireless electronic communication channels may include, but is not limited to, Wi-Fi, Bluetooth, Bluetooth LE, GPRS (General Packet Radio Service), Enhanced Data GSM Evolution (EDGE) etc. [0035] Unless defined otherwise, all other technical and scientific terms used herein have the same meaning as is commonly understood by a skilled person to which the subject matter herein belongs.

[0036] According to an aspect there is a system for detecting an eye condition. The system comprises a processor arranged in signal communication with a user interface device; the user interface device for displaying a visual field test and configured to receive a user input in relation to an abnormal region associated with the visual field test; wherein the processor is configured to receive data associated with the abnormal region to provide a measurement of an eye condition.

[0037] Referring to Figure 2, the system 10 comprises a processor 12 arranged in signal or data communication with a user interface device 14. The signal or data communication may be via wired or wireless channels. In some embodiments, the processor 12 can be integrated with the user interface device 14. The user interface device 14 may be a portable computer device, such as, but not limited to, a mobile phone, a tablet PC or the like. [0038] In some embodiments, images 30 used for visual field testing, such as those shown in Figure 3, may be pre-generated and stored in the processor 12 or the user interface device 14. In other embodiments, the images may be stored in remote servers such as cloud servers. [0039] In the context of the mobile phone, the visual field tests may be provided to a user via a downloadable dedicated software application, colloquially referred to as an‘app’.

[0040] It is to be appreciated that the images shown in Figure 3 are designed to function as stimulus for testing multiple locations in each of a user’s eye for visual field defect. These images may change or be updated at a pre-determined frequency before the test commences. The images may also be made to flash at a pre determined frequency. When the stimulus flashes, test subjects with visual field defects will observe the abnormal area.

[0041] In some embodiments, the stimulus settings can also be varied by size (see Figure 3: top row), frequency of flicker and colour (see Figure 3: bottom row).

[0042] Upon display of an image, a user or test subject can provide user input 32, via the use a stylus pen or via a touch screen of the user interface device (if available), to demarcate or mark the size and location of visual field defects. An example of how a region of visual field defect can be selected or identified is shown in Figure 4a. Once the demarcated portion or location is selected, the app is operable to quantify the area demarcated 34 (see Figure 4b).

[0043] In some embodiments, the demarcated region could be incomplete due to a variety of reasons (e.g. an incomplete circle). In such embodiments, the app may complete the selected region using extrapolation or interpolation methods. [0044] It is to be appreciated that the method of collecting response from a test subject on the touch screen of a portable device is advantageous over the prior art machine. The method of quantifying collected response is also advantageous over the prior art machine. The interactive involvement of the test subject helps them stay engaged throughout the test. [0045] It is to be appreciated that the use of the app on a portable device, for example, a tablet PC is advantageous over the prior art machine. With an app downloaded onto the portable device, medical practitioners such as doctors can perform VF testing in many more settings where visual field tests are not usually done e.g. consultation rooms, community screenings, home visits. Test subjects without VF defects are excluded efficiently reducing unnecessary conventional VF testing. Test subjects with VF defects will be diagnosed earlier and treatment for eye conditions such as glaucoma can be initiated.

[0046] In some embodiments, the region selected by the test subject is subjected to further analysis, and a measurement value obtained. This is shown in Figure 5. In some embodiments, the measurement value may be based on a percentage of a region of ‘defect’ or‘abnormality’ selected by the test subject with reference to the whole area of the image shown to the test subject. For example, if the region of ‘defect’ selected by the user is 20% of the image, the measurement value may be 0.2.

[0047] In some embodiments, when there is no visual field defect received or detected in relation to the first set of test images, the detection is terminated.

[0048] In some embodiments, the visual field tests could be staged. In particular, where it is tested there are no visual field defects detected based on a first set of images of varying colours, resolution, sizes and/or shapes, the visual field test for a test subject could be terminated at an early stage without the test subject needing to go through further tests. Where some visual field defects are indicated by a test subject (see Figure 6), the selected abnormal region can be sent to the processor for further analysis. The further analysis can include additional test images (in the form of a second set, third and subsequent set of images) to provide an indication of the extent or severity of visual defect of the test subject.

[0049] In summary, the system 10 provides for a first set of test images to detect whether a test subject suffers from one or more visual field defects. Based on the first set of test images, if a test subject suffers from at least one visual field defect, i.e. if a region of abnormality is selected by the test subject, a second set of test images may be shown to the test subject to determine the severity of the visual defect experienced by the test subject.

[0050] As an example, for a first set of test images, each test image comprising objects (with a predetermined size) arranged adjacent to each other with contrasting colours may be displayed to the test subject. For example the object may be in the form of a 64 pixels by 64 pixels block-like structure arranged adjacent another object of similar or smaller size of contrasting colours, whereby there is a colour 1 and a colour 2 such as colour 1 blue/colour 2 yellow, colour 1 black/colour 2 white, colour

1 red/colour 2 green. In some embodiments the initial contrasting colours are high colour contrast of complementary colours sometimes referred to as opposite colours that provide a significant chromatic contrast this is depicted as black and white in Figure 3 top panel. If the test subject identifies one or more areas of defect or abnormality, then a second set of test images of smaller resolution and/or less contrasting colours between an image and its adjacent image can be shown to the test subject to determine the severity of the defect. In some embodiments the second set of test images use less contrasting colours that are of medium colour contrast of analogous colours sometimes referred to as harmonizing colours that provide a minor chromatic contrast such as colour 1 blue/colour 2 green, colour 1 yellow/colour

2 orange, colour 1 red/colour 2 violet this is depicted as greyish black and greyish white in Figure 3 bottom panel. If the test subject identifies one or more areas of defect or abnormality based on the second set of test images, a third set (and subsequent set) of test images may be displayed to the test subject. In some embodiments the subsequent set of test images use less contrasting colours that are of low colour contrast that may be shades of the same colour such as colour 1 blue/colour 2 cyan, colour 1 violet/colour 2 lavender, colour 1 red/colour 2 pink this is depicted as dark grey and light grey in Figure 5. In general, in successive sets of test images it is less likely for a test subject to identify any area of defect unless the severity of the eye defect is high.

[0051] In some embodiments, the test has a graded colour contrast along the axis of colour confusion. For example each separate sub test 1 ) High color contrast (e.g. black white), 2) Medium (more greyish black vs greyish white), 3) Low (dark grey vs light grey) will be done irrespective of whether there was abnormality in high color contrast or not.

[0052] In some embodiments, the frequency of switching between images in each set of test images may vary between 1 frame per second and 30 frames per second.

[0053] In some embodiments, the size of each object in a test image may vary between 2 by 2 pixels and 64 by 64 pixels. In some embodiments, the size of each object in a test image may vary between 4 by 4 pixels and 60 by 60 pixels. In some embodiments, the size of each object in a test image may vary between 5 by 5 pixels and 50 by 50 pixels. In some embodiments, the size of each object in a test image may vary between 10 by 10 pixels and 40 by 40 pixels. [0054] In some embodiments, 24 degrees of visual field is tested. In such embodiments the size of the objects arranged adjacent to each other in contrasting colours is large varying between 5 by 5 pixels and 64 by 64 pixels, this is depicted in right side of Figure 3, both top and bottom panels. In some embodiments, 10 degrees of visual field is tested. In such embodiments the size of the objects arranged adjacent to each other in contrasting colours is smaller varying between 10 by 10 pixels and 40 by 40 pixels, this is depicted in the top central panel of Figure 3. In some embodiments, 24 degrees of visual field tested first followed by testing 10 degrees of visual field.

[0055] In some embodiments, the colour contrast between each object and the adjacent object may be relatively less in each successive set of test images. In some embodiments, the colour contrast between each object and the adjacent object may be complementary colours in the first set of test images, adjacent colours in a second set of test images and different hues for the same colour in a successive set of test images. [0056] In some embodiments, the app may display the user interface in the following sequence to obtain information from a test subject.

[0057] Step 1 : User selects a‘new test’ option on a home screen.

[0058] Step 2: User fills the test information such as Name, identity number or other identifiers, date etc. [0059] Step 3: User can set the test conditions such as color- patterns and rate of change of patterns.

[0060] The user interface device 14 then displays the test images. Once the test images are displayed, step 4: The user tries to differentiate between the changing patterns and encircles or mark out any recognized spots. (Incomplete circles or shapes will be completed automatically)

[0061] Step 5: User can return to previous selection and undo the selection if required or continue to mark the recognized changes and finally click the done button

[0062] Step 6: The application measures the area marked and displays the final results to the user, the results are also saved on the device to be viewed later.

[0063] In some embodiments, a virtual reality (VR) device, such as a VR headset or VR goggle may be used in conjunction with a mobile phone with the app installed thereon for providing various test images or sets of test images to a test subject. The VR headset may be equipped with sensors or detectors to detect movement and position of a test subject wearing the VR headset. Such movement and position may be correlated to the selection of a defect area or region.

[0064] It is to be appreciated that the app uses a novel stimulus (in the form of test images) which simultaneously tests multiple locations in each eye for visual field defects. When the stimulus flashes, test subjects with VF defects will observe one or more abnormal areas and will be given an opportunity to provide feedback in the form of responses to the test images.

[0065] The system and method as envisaged may be used to detect the presence of eye conditions or diseases such as glaucoma. There are other eye conditions which can result in VF defects and may benefit from screening tests. This project focuses on developing a novel visual field application (app) on portable devices to screen test subjects for vision loss from glaucoma and other eye diseases and to classify the severity of VF defect.

[0066] A table indicating the various advantages of the envisaged system over a prior art (FIVF) machine is shown in Figure 7. As may be appreciated, the system and method is especially suited to detect scotoma. In addition, as contrary to the in depth testing by the prior art machine which test the whole visual field, the present system will focus on the area of scotoma to further test the depth or severity of visual field defect on a test subject. Such an arrangement provide greater specificity in testing and is able to save time, making visual field tests more efficient.

[0067] It is to be appreciated that the method of providing test images for the detection of eye condition may be programmed and stored in a non-transitory computer readable medium, such as a memory unit in the user interface device 14 or the processor 12. When executed, the non-transitory computer readable medium executes the method for detecting an eye condition, the method comprises the steps of: displaying on a user interface a first set of visual field test images for input by a user; receiving a user input in relation to an abnormal region associated with the first set of visual field test images; wherein if an abnormal region is present, the method further display a second set of test images for detecting the severity of the visual field defect.

[0068] In some embodiments when no user input is detected, the method terminates.

[0069] According to another aspect there is an apparatus for detecting an eye condition including a processor module arranged in signal communication with a user interface module; the user interface module configured to display a visual field test and configured to detect a user input in relation to an abnormal region associated with the visual field test; wherein the processor module is configured to calculate a measurement of an eye condition based on the detected user input.

[0070] In some embodiments, the apparatus comprises a portable device, such as, but not limited to, a mobile phone, a tablet PC or the like, for example, a tablet PC.

[0071] It is to be appreciated that the significant variation and contrast between each object and the adjacent object in the set of test images allows the tests to be performed without requiring the test subjects eyes to be at a set location or distance from the images allowing the apparatus to be portable and take up less space. [0072] In some embodiments, the user input is in the form of an area demarcated by a user.

[0073] In some embodiments, if no user input is detected the measurement of the eye condition is regarded as normal.

[0074] It should be further appreciated by the person skilled in the art that variations and combinations of features described above, not being alternatives or substitutes, may be combined to form yet further embodiments falling within the intended scope of the invention.

[0075] As would be understood by a person skilled in the art, each embodiment, may be used in combination with other embodiment or several embodiments.

THE FOLLOWING NUMBERED PARAGRAPHS CONTAIN STATEMENTS OF BROAD COMBINATIONS OF THE INVENTIVE TECHNICAL FEATURES HEREIN DISCLOSED:

1. A system for detecting an eye condition comprising

a processor arranged in signal communication with a user interface device; the user interface device for displaying a visual field test and configured to receive a user input in relation to an abnormal region associated with the visual field test;

wherein the processor is configured to receive data associated with the abnormal region to provide a measurement of an eye condition.

2. The system of clause 1 , wherein the user interface device include a mobile computer device.

3. The system of clause 2, wherein the mobile computer device is a mobile phone or a tablet PC.

4. The system of any one of the preceding clauses, wherein the visual field test includes a plurality of images provided to a user via the user interface device.

5. The system of any one of the preceding clauses, wherein the visual field test comprises a first set of test images for detecting the presence of a visual field defect and a second set of test images for detecting the severity of the visual field defect.

6. The system of clause 5, wherein a second set of test images is dependent on the user input provided by the user in relation to the first set of test images. 7. The system of clause 6, wherein if there is no visual field defect received in relation to the first set of test images, the detection is terminated.

8. A method for detecting an eye condition comprising

displaying on a user interface a first set of visual field test images for input by a user;

detecting a user input in relation to an abnormal region associated with the first set of visual field test images;

Wherein if the user input is detected, the method further includes the step of displaying a second set of test images for detecting the severity of the visual field defect.

9. The method according to clause 8, wherein if no user input was detected, the method terminates.

10. A non-transitory computer readable medium containing executable software instructions thereon wherein when executed performs a method for detecting an eye condition, the method comprises the steps of:

wherein if the user input is detected, the method further display a second set of test images for detecting the severity of the visual field defect.

1 1 . An apparatus for detecting an eye condition including

a processor module arranged in signal communication with a user interface module;

the user interface module configured to display a visual field test and configured to detect a user input in relation to an abnormal region associated with the visual field test;

wherein the processor module is configured to calculate a measurement of an eye condition based on the detected user input.

12. The apparatus of clause 1 1 , wherein the user input is in the form of an area demarcated by a user.

13. The apparatus of clause 12, wherein if no user input is detected the measurement of the eye condition is regarded as normal.

Claims

1. A system for detecting an eye condition comprising: a processor arranged in signal communication with a user interface device; the user interface device for displaying a visual field test and configured to receive a user input in relation to an abnormal region associated with the visual field test; wherein the processor is configured to receive data associated with the abnormal region to provide a measurement of an eye condition.

2. The system according to claim 1 , wherein the user interface device includes a mobile computer device.

3. The system according to claim 2, wherein the mobile computer device is a mobile phone or a tablet PC.

4. The system according to any one of the preceding claims, wherein the visual field test includes a plurality of images provided to a user via the user interface device.

5. The system according to any one of the preceding claim, wherein the visual field test comprises a first set of test images for detecting the presence of a visual field defect and a second set of test images for detecting the severity of the visual field defect.

6. The system according to claim 5, wherein a second set of test images is dependent on the user input provided by the user in relation to the first set of test images.

7. The system according to claim 6, wherein if there is no visual field defect received in relation to the first set of test images, the detection is terminated.

8. A method for detecting an eye condition comprising displaying on a user interface a first set of visual field test images for input by a user; detecting a user input in relation to an abnormal region associated with the first set of visual field test images; wherein when an abnormal region is detected, the method further displays a second set of test images for detecting the extent or severity of the visual field defect.

9. The method according to claim 8, wherein if no user input was detected, the method terminates.

10. A non-transitory computer readable medium containing executable software instructions thereon wherein when executed performs a method for detecting an eye condition, the method comprises the steps of: displaying on a user interface a first set of visual field test images for input by a user; detecting a user input in relation to an abnormal region associated with the first set of visual field test images; wherein when an abnormal region is detected, the method further displays a second set of test images for detecting the extent or severity of the visual field defect.

1 1 . An apparatus for detecting an eye condition including a processor module arranged in signal communication with a user interface module; the user interface module configured to display a visual field test and configured to detect a user input in relation to an abnormal region associated with the visual field test; wherein the processor module is configured to calculate a measurement of an eye condition based on the detected user input.

12. The apparatus according to claim 1 1 , wherein the user input is in the form of an area demarcated by a user.

13. The apparatus according to claim 12, wherein if no user input is detected the measurement of the eye condition is regarded as normal.