ABSTRACT
Introduction: The rise of telemedicine in the wake of the COVID-19 pandemic has posed challenges for ophthalmologists and optometrists, as there are hardly any smartphone applications that meet high accuracy requirements for obtaining visual acuity (VA) in clinical use. The application vision.app is a novel smartphone app that adjusts the angular size of the optotype based on the face-device distance in real time. The high spatial resolution of modern smartphone screens facilitates measurements at a handheld distance, which makes it particularly valuable for use in pediatric populations which struggle to focus on distant stimuli. Method(s): As part of a prospective validation study, we obtained the best corrected VA (BCVA) in n = 48 eyes using vision.app. The app displayed a Landolt C optotype and used a 4 force choice procedure loosely based on FrACT (Freiburg Visual Acuity & Contrast Test). Results were compared to BCVA measurements taken using a standard ETDRS chart placed at 10 feet (3 m). To assess the similarity of measurement methods, a statistical analysis was performed based on a two-tailed, paired t test. Result(s): The t-test revealed no significant difference in measured BCVA (P = 0.415), with a mean difference between clinical and app measurements of less than one letter (0.005 logMAR). Conclusion/Relevance: Self-measured visual acuity with vision.app is accurate compared to the gold standard. This has the potential to facilitate home monitoring for adult patients;however, a separate study is warranted to validate the results for children. Copyright © 2022