The evaluation of a novel tool to remotely assess visual acuity in chronic uveitis patients during the COVID-19 pandemic

Claessens, J. L.; van Egmond, J.; de Boer, J. H.; Wisse, R. P. L.

Background: Restrictions due to the recent COVID-19 pandemic catalysed the deployment of telehealth solutions. A novel web-based visual acuity test, validated in a healthy population, may be of great value in the follow-up of uveitis patients. Objective To determine the measurement accuracy of the unsupervised remote Easee web-based visual acuity test in uveitis patients, when compared to a conventional in-hospital assessment. Methods: Cross-sectional diagnostic accuracy study. Between April 2020 and September 2020, consecutive adult uveitis patients were invited for the web-based visual acuity test (index test) within two weeks prior to their conventional in-hospital assessment (reference test). Results: A total of 269 patients were invited by mail, of whom 84 visited the website (31%). Ultimately 98 eyes met the criteria for statistical analysis. The mean difference between the two tests was low and non-significant: 0.02 logMAR (SD 0.12, P = 0.085). The 95% limits of agreement ranged from -0.21 to 0.26 logMAR. No relevant differences were identified in clinical characteristics between subgroups with a good performance (i.e. difference between the tests <=0.15 logMAR) or underperformance (i.e. difference >0.15 logMAR) on the web-based test. Conclusion: The web-based visual acuity test is a promising tool to remotely assess visual acuity in the majority of uveitis patients, especially relevant when access to ophthalmic care is limited. No association between patient- or uveitis-related variables and (under)performance of the test were identified. These outcomes underline the potential of remote vision testing in other common ophthalmic conditions. A proper implementation of this web-based tool in health care could be of great value for revolutionizing teleconsultations.