Automated determination of distance visual acuity: Towards teleophthalmology services
Kumar, S., Bulsara, M., & Yogesan, K. (2008). Automated determination of distance visual acuity: Towards teleophthalmology services. Clinical and Experimental Optometry, 91(6), 545-550. doi:10.1111/j.1444-0938.2008.00267.x
Purpose: The aim of this study was to evaluate the visual acuity scores of a computer-based visual function testing (CVFT) system. The automated chart uses logMAR notation (logarithm of the minimum angle of resolution) and randomised tilting E as optotype. The test was conducted using a laptop computer.
Methods: This prospective, clinic-based, test validation study was based on a model of repeatability in two observations. The right eyes of a total of 104 participants were randomly tested with both CVFT and the manual, gold standard Early Treatment of Diabetic Retinopathy Study (ETDRS) chart.
Results: The mean difference between CVFT and ETDRS was -0.01 ± 0.11 (SD) logMAR units. The Spearman Rank correlation coefficient (r) between the absolute difference and the average was 0.35. The average time for testing one eye was 54.7 ± 11.89 seconds. The mean difference between two consecutive, repeated CVFT tests in the same eye was 0.02 ± 0.07 logMAR units (paired t-test p = 0.046).
Conclusions: A novel, automated visual acuity testing application is reported. This automated system should be a useful tool for mass screening of visual impairment in rural and remote regions with its ease of use and shorter testing time.
peer-reviewed, computerised eye testing, teleophthalmology, visual acuity