Using an open-source tablet perimeter (Eyecatcher) as a rapid triage measure for glaucoma clinic waiting areas

Abstract

BackgroundGlaucoma services are under unprecedented strain. The UK Healthcare Safety Investigation Branch recently called for new ways to identify glaucoma patients most at risk of developing sight loss, and of filtering-out false-positive referrals. Here, we evaluate the feasibility of one such technology, Eyecatcher: a free, tablet-based ‘triage’ perimeter, designed to be used unsupervised in clinic waiting areas. Eyecatcher does not require a button or headrest: patients are simply required to look at fixed-luminance dots as they appear.MethodsSeventy-seven people were tested twice using Eyecatcher (one eye only) while waiting for a routine appointment in a UK glaucoma clinic. The sample included individuals with an established diagnosis of glaucoma, and false-positive new referrals (no visual field or optic nerve abnormalities). No attempts were made to control the testing environment. Patients wore their own glasses and received minimal task instruction.ResultsEyecatcher was fast (median: 2.5 min), produced results in good agreement with standard automated perimetry (SAP), and was rated as more enjoyable, less tiring and easier to perform than SAP (all p<0.001). It exhibited good separation (area under receiver operating characteristic=0.97) between eyes with advanced field loss (mean deviation (MD) < −6 dB) and those within normal limits (MD > −2 dB). And it was able to flag two thirds of false-positive referrals as functionally normal. However, eight people (10%) failed to complete the test twice, and reasons for this limitation are discussed.ConclusionsTablet-based eye-movement perimetry could potentially provide a pragmatic way of triaging busy glaucoma clinics (ie, flagging high-risk patients and possible false-positive referrals).

Can Psychophysics Be Fun? Exploring the Feasibility of a Gamified Contrast Sensitivity Function Measure in Amblyopic Children Aged 4–9 Years

“…Ideally, information regarding viewing distance would have been factored into the psychophysical algorithm live, during testing [i.e., as we have done previously when estimating visual fields ( 30 )]. We did not do so here, however, as integrating live measurements is a non-trivial task (i.e., requires extensive pre-processing, and additional code), and if performed incorrectly can be counterproductive.…”

Glaucoma home-monitoring using a tablet-based visual field test (Eyecatcher): An assessment of accuracy and adherence over six months

“…Visual fields were assessed using a custom screen-perimeter ( Fig 1B ), implemented on an inexpensive HP Pavilion x360 39.6 cm (15.6”) tablet-laptop (HP Inc., Paolo Alto, CA, United States). The test was a variant of the ‘Eyecatcher’ visual field test: described previously 33,38 and freely available online (https://github.com/petejonze/Eyecatcher). It was modified in the present work to more closely mimic conventional static threshold perimetry; most notably by: employing a ZEST thresholding algorithm 41 , a central fixation-cross, and a button press response.…”

“…Several portable perimeters have been developed that use ordinary tablet-computers (e.g., Melbourne Rapid Fields 30–32 ; Eyecatcher 33 ) or head-mounted displays (e.g., imo 34,35 , Mobile Virtual Perimetry 36 ). Such devices are small and inexpensive enough for patients to take home, and several appear capable of approximating conventional SAP when operated under supervision 31,37,38 .…”

A case control study examining the feasibility of using eye tracking perimetry to differentiate patients with glaucoma from healthy controls

“…Over the last decade several groups have explored the possibility of performing perimetry by tracking eye movements [7][8][9][10][11][12][13] . Eye trackers have long been used to monitor fixation during visual field assessment, but eye tracking may also be useful for determining whether a stimulus has been seen.…”