Description:
21015
Background
Vision screening in both clinical and basic science is a critical step that quantifies functional deficits in the visual system. In clinical practice, vision screening is essential for disease diagnosis and monitoring; in basic science, it can quantify sensory or perceptual performance or ensure that research participants meet specific study inclusion or exclusion criteria. Recent social distancing measures and developments in communication, display and sensor technologies mean that remote vision screening may play a significant role in teleophthalmology. Significant vision changes could go undetected in these long intervals between tests, especially for gradual loss, therefore self-administered vision screening may serve an important home monitoring role particularly in remote and medically underserved locations.
The human visual system comprises multiple interdependent pathways that are structurally and functionally specialized and may be selectively affected across the lifespan. Comprehensive vision screening ideally requires the administration of multiple tests that asses the integrity of different visual pathways however, in practice, combined limitations on the time available to clinicians and basic scientists and on the burden of assessment on subjects, severely limit the number of tests that can be administered. Vision tests require the subject to learn a new task or a new set of stimuli for each test and to complete many trials where they are forced to guess because the paradigm requires the presentation of sub-threshold stimuli.
These factors can be frustrating for subjects and may confound attention, learning and memory effects with visual function deficits. These pressures have led to compromises in the number and duration of tests that are administered, with the risk that the vision screening is inaccurate (due to noisy or under-constrained data) or incomplete (because only a subset of tests is administered).
Technology Overview
FInD has the potential to address all these limitations by administering a quick test that can be administered multiple times in a single clinic visit or screening. The same paradigm is employed for multiple different stimulus types, so a comprehensive assessment of the function of multiple brain areas can be completed quickly and efficiently. The easy-to-understand protocol is employed for all tests, so human subjects of all abilities can complete the test without needing to learn a new protocol for different tests and includes easy and difficult stimuli simultaneously, so subjects do not have to remember the test signal for the current task. FInD tests can be self-administered providing for at home/patient room testing.
For FInD (Foraging Interactive D-prime) human subjects search a short sequence of grids and report which cells in each grid contain targets of differing signal intensities with the subject’s response in each cell then classified. Signal detection theory is used to calculate sensitivity to the stimuli. The signal intensities in successive grids are updated based on the observer’s responses on previous grids to maximize the efficiency of the test.
Benefits
- Quick – 30 seconds for a comprehensive test, compared with 18 minutes with alternative methods
- Generalizable to a broad range of tests for different visual pathways without subjects learning new tasks for each test
- Intuitive and easy to administer for broad audience including age, culture and cognitively-impaired subjects
- Same general method is used for multiple tests of different visual function pathways
- Can be self-administered and does not require a clinician or technician to proctor the test and can be administered away from the clinic, e.g. in the home, sports arena, battlefield or for ecological momentary assessment
Applications
- Detecting and monitoring the progression of a range of ophthalmic diseases, e.g. age-related macular degeneration, glaucoma and amblyopia
- Endpoint for optometric correction, e.g. contact lenses, spectacles, intraocular lenses. Numerous optometric companies are seeking new clinical trial endpoints in this area
- Endpoint for neuro-ophthalmic disorders, e.g. traumatic brain injury, head trauma, autism spectrum disorder, ADHD. Numerous drug discovery companies are seeking new clinical trial endpoints in this area