Abstract
Purpose: :
To present the worsening in reading speed for patients with geographic atrophy (GA) associated with AMD, who had baseline visual acuity worse than 20/50 in their better-seeing eye with GA.
Methods: :
Data from a large NIH-funded natural history study of GA were analyzed for the maximum reading rate at baseline and for four years of follow-up. Reading was measured for paragraphs of unrelated words presented on a monitor, using 9 character sizes scaled to acuity. The maximum reading rate (here called reading rate) was assessed annually for the eye with better visual acuity at baseline.
Results: :
For this reading test, a comparison group of patients with only drusen had a mean reading rate of 130 words per minute (wpm), with no patient having a rate lower than 100 wpm. Fifty eight patients with GA had best-corrected ETDRS visual acuity worse than 20/50. At baseline, the mean visual acuity for these GA patients was 55 wpm, with 43% having reading rates of less than 50 wpm. At follow-up, reading rates were less than 50 wpm for 52% at 1 year, 69% at 2 years, 78% at 3 years, and 81% at 4 years. Three patients (9% of those with 1 year f/u) improved by 10 or more wpm between baseline and the first annual follow-up visit.
Conclusions: :
We have previously shown that there is only slow change in visual acuity over time in eyes with visual acuity worse than 20/50 at baseline. However, reading rate continues to decline progressively, reflecting both worsening of visual acuity and enlargement of the atrophic area and consequent scotoma.
Keywords: age-related macular degeneration • clinical (human) or epidemiologic studies: natural history