Abstract
BACKGROUND/OBJECTIVES: The aim of this study was to evaluate the change in visual acuity (VA) in participants with intermediate age-related macular degeneration (iAMD) over two years when categorised by the presence or absence of incomplete retinal and retinal pigment atrophy (iRORA) and subretinal drusenoid deposits (SDD). SUBJECTS/METHODS: In this multicentre cohort study, participants with iAMD were classified as: i) iAMD with no iRORA or SDD; ii) iAMD with SDD with no iRORA; iii) iAMD with iRORA with no SDD and iv) iAMD with iRORA and SDD. The change in best recorded visual acuity (BRVA) over two years in the whole cohort and in each sub-category was analysed using linear mixed effect models employing an unstructured covariance structure. Associations with age, sex and baseline BRVA were evaluated. RESULTS: 983 eyes from 805 participants were analysed. The mean baseline VA changed from 79.8 (SD 8.1) to 77.7 (SD 10.1) Early Treatment Diabetic Retinopathy Study (ETDRS) letter score at two years, with a mean unadjusted change in BRVA of -0.33 ETDRS letters (95% CI -0.72,0.06); P = 0.10 at 6 months, -0.65 ETDRS letters (95% CI -1.14, -0.16); P = 0.01 at 12 months, -1.45 ETDRS letters (95% CI -2.03, -0.86); P < .001 at 18 months and -2.16 ETDRS letters (95% CI -2.79, -1.53); P < .001 at 24 months. All sub-categories showed a small decline in BRVA. Increasing age and lower baseline visual acuity were associated with lower BRVA over two years. CONCLUSION: Eyes with iAMD experience a small mean decline of ~2 letters over two years. Overall, these changes may not represent a clinically meaningful difference.