Virtual Reality Test of Strabismus
Research type
Research Study
Full title
A comparison of prism cover testing and a virtual reality headset-based test in the objective assessment of ocular deviation
IRAS ID
268329
Contact name
Nisha Nixon
Contact email
Sponsor organisation
Norfolk and Norwich University Hospitals NHS Foundation Trust
Duration of Study in the UK
3 years, 0 months, 1 days
Research summary
Research Summary
Strabismus, or squint, describes any misalignment of the eyes, and can affect both children and adults. As a result,
the images of the outside world conveyed to the brain from the two eyes do not correspond, which can result in
diplopia, or ‘double vision’. As well as impacting on a patient’s functionality, strabismus can have cosmetic and
psychosocial ramifications. Furthermore, if left untreated in childhood, strabismus can lead to life-long visual
impairment, despite best spectacle correction.Current treatment is guided by the exact nature of the strabismus and the patient’s age; options include spectacle
prescription to correct underlying refractive error, use of prisms to control deviation, or in certain cases, surgery. In
order to investigate the size and type of strabismus present, and determine the best management, tests of ocular deviation are performed in Eye Clinics.Quantitative objective assessment of the angle of horizontal and vertical strabismus is currently performed using the prism cover test - the patient is asked to look at a fixation target, and prisms of increasing power are placed in front of one eye until the ocular deviation is neutralised (i.e. there is no movement of the eyes to take up fixation). The test can provide accurate numerical recordings to aid in monitoring and surgical planning.
However, the prism cover test requires a range of different prisms, the presence of a near and distance fixation target, a trained examiner, and a patient able to fixate at an appropriate target without moving their head for the duration of the test. In this study, we investigate whether a virtual reality headset-based test can produce comparable measurements of ocular deviation to the traditional prism cover test, without the need for prisms, or control of head posture.
Summary of Results
New digital technologies (augmented reality headsets, eye-tracking) may potentially allow for automated assessments of misalignment of the eyes (strabismus). Here, we evaluate the feasibility of a novel, open-source test of strabismus (STARE) as an automated screening tool.
Methods: We applied the system to adults with an established diagnosis of strabismus, and quantified the ability of the test to distinguish between those with horizontal misalignment and those without.
Results: Nineteen patients with strabismus were recruited (mean age 58.7 ± 22.4 years). STARE was able to identify the presence of horizontal strabismus with an area under the curve of 1.00 (100% sensitivity and 100% specificity).
Conclusions: STARE shows promise as a simple, automated tool for performing a screening assessment of strabismus. It is a rapid (60 second) test that can be performed using a consumer headset with integrated eye-tracking, and might conceivably be used remotely by non-specialists in future as a means of highlighting individuals needing face-to-face specialist care.REC name
North East - Newcastle & North Tyneside 1 Research Ethics Committee
REC reference
19/NE/0305
Date of REC Opinion
3 Oct 2019
REC opinion
Favourable Opinion