Intersession repeatability of reading performance measures in patients with neovascular age-related macular degeneration

Purpose:To assess the intersession repeatability of reading performance measures in patients with previously treated neovascular age-related macular degeneration and good best-corrected visual acuity (≥20/40 Snellen).Methods:Ninety-one patients (91 eyes) with a diagnosis of previously treated neovascular age-related macular degeneration and good best-corrected visual acuity (≥20/40 Snellen) were prospectively enrolled. Reading performance metrics were assessed using Radner charts, and these measurements were repeated after 7 days to obtain the intersession repeatability. To test repeatability, we calculated the intraclass correlation coefficient, the 95% coefficient of repeatability, and the coefficient of variation for each reading parameter: 1) reading acuity (RA - LogRAD); 2) maximal reading speed - words per minute; 3) RA score (RA score - LogRAD); and 4) critical print size - LogRAD.Results:Mean ± standard deviation best-corrected visual acuity was 0.13 ± 0.01 logMAR [range: 0.00-0.30 logMAR]. The intraclass correlation coefficient values indicated a good reliability for all the analyzed metrics (0.901 for RA; 0.859 for max reading speed; 0.906 for RA score; and 0.868 for critical print size). The coefficient of repeatability was 0.2 LogRAD for RA, 63.2 words per minute for max reading speed, 0.2 LogRAD for RA score, and 0.2 LogRAD for critical print size. Coefficient of variation was 5.5% for RA, 8.9% for max reading speed, 5.8% for RA score, and 6.9% for critical print size.Conclusion:Reading performance metrics are characterized by good values of intersession repeatability in patients with neovascular age-related macular degeneration with good best-corrected visual acuity. Our findings may grant the employment of such measures in trials assessing the visual outcome in these patients.