Purpose
To evaluate the rates of vision loss compared with baseline in participants with geographic atrophy (GA) at baseline and those that developed GA in two major clinical trials.
Methods
The Age Related Eye Disease Study (AREDS) was a multi-center, double masked randomized clinical trial that enrolled 4757 participants with varying degrees of macular degeneration. The AREDS 2 was a multi-center, double masked phase 3 study which enrolled 4203 participants who were at risk for progression to advanced age related macular degeneration. In both studies, best-corrected visual acuity was obtained at baseline and at yearly intervals using the standard protocol from the Early Treatment of Diabetic Retinopathy Study (ETDRS).
Results
In AREDS, 259 eyes of 217 participants were identified as having GA at baseline. Of these, 79 had central GA. By the 5 year follow-up, 1267 eyes of 908 participants developed GA, 259 eyes were defined as having central GA. For those with GA at baseline, 48.7% of participants lost more than 10 letters and 36.8% lost more than 15 letters at 5 years compared with baseline. For those that developed GA during follow up, 47.1% of eyes lost more than 10 letters of vision, while 36.8% lost more than 15 letters at 5 years. Participants that developed GA during the study that had better initial visual acuity (20/80 or better), on average lost more letters than those with worse visual acuity when diagnosed with GA at 5 years (20 letters vs. 5.7 letters). In AREDS 2, 524 eyes of 418 participants were identified as having GA at baseline, of which 170 eyes had central GA. By 5 years of follow-up, an additional 868 eyes of 791 participants developed GA, 291 of which had central GA. For those with GA at baseline, 44.2% of participants lost more than 10 letters, and 33.5% lost more than 15 letters at 5 years follow up. For those that developed GA during follow up, 50.0% of participants lost more than 10 letters, and 35.0% lost more than 15 letters at 5 years.
Conclusions
Participants in the AREDS and AREDS2 study with geographic atrophy trended toward progressive visual loss. As expected, those participants with better initial visual acuity tended to lose more letters than those with worse initial visual acuity. This data may guide other investigators in planning for future studies of GA associated with AMD.
Keywords: 412 age-related macular degeneration •
754 visual acuity