Reliability of self-measurement of visual acuity in AMD patients with two electronic devices based on the ETDRS chart: A randomized study

Abstract

Age-related macular degeneration (AMD) requires continuous visual acuity (VA) monitoring, increasing the burden on the health care system. Self-measurement VA tests are available on various devices. However, none of them have been based on an internationally validated benchmark chart, such as that of the Early Treatment Diabetic Retinopathy Study (ETDRS). The goal of this study was to assess the reliability of two digitized ETDRS charts adapted to two electronic devices for self-measurement of VA. A prospective, single-center, 1:1 randomized, two-arm, parallel group trial was conducted. The main objective was to compare VA variation as conventionally measured on a 4-m ETDRS chart versus self-measured with digitized ETDRS charts in patients treated for AMD. At each visit, conventional measurement and patient self-measurement, either on a computer at 80-cm (arm 1) or on a tablet at 40-cm (arm 2), were performed. Eighty patients were included (25 men, 55 women, mean age 81.3±7.4 years). No significant differences were observed between VA variation, conventionally measured and self-measured on a computer (arm 1; P=0.914) or tablet (arm 2; P=0.913). These results confirm the reliability of these two methods for self-measurement of VA, and will lead to the development of a wider "telemedicine" project extended to self-measurement of VA in various pathologies.