Ranibizumab treatment improves the reading speed of patients with neovascular age-related macular degeneration: A nonrandomized clinical trial using the Radner reading chart

Abstract

Purpose: Intravitreal injections with anti-vascular endothelial growth factor (VEGF) drugs can slow progression in neovascular age-related macular degeneration (nAMD). Best spectacle-corrected visual acuity (BSCVA) and/or central retinal thickness (CRT) are common barometers of efficacy of this treatment. However, BSCVA does not accurately measure reading ability, which is often severely impacted by nAMD. Since most studies on the effect of intravitreal anti-VEGF injections on reading ability in nAMD have limitations, we conducted an open-label nonrandomized non-blinded self-controlled clinical trial using Radner Charts, a standardized, validated tool for measuring reading ability.Methods: Patients newly diagnosed with active nAMD and scheduled to undergo induction ranibizumab treatment (monthly treatments for 3 months) were recruited by convenience sampling in 2010-2013 at a university hospital. The primary outcome was change in Radner Chart-determined reading speed (maximum words/minute [wpm]) at 3 months (1 month post-third injection) relative to baseline. Secondary outcome measures were 3-month change in BSCVA and CRT. Treatment-induced effects on wpm, BSCVA, and CRT were determined with Wilcoxon tests. Spearman correlations between these variables were evaluated.Results: The injections significantly improved wpm (48 to 75), BSCVA (+9 letters), and CRT (357 to 224 μm) (all p<0.0001). BSCVA, but not CRT, correlated with wpm at baseline and 3 months (p=0.0004 and 0.03, respectively). BSCVA and CRT were not correlated, unless change in these variables was considered, possibly because of a non-linear relationship.Conclusion: Anti-VEGF treatment significantly improved reading ability. Whether BSCVA can serve as a clinically meaningful assessment of reading ability requires further research. Baseline variables may not help to identify patients with poor reading speed responses to treatment.