Researchers recently found that geographic atrophy (GA) had a severe functional impact on patients’ vision and is linked to a rapid rate of lesion progression over a two-year period.

A pair of global, prospective, non-interventional, observational clinical trials were conducted, the first of which evaluated 295 patients with bilateral GA without choroidal neovascularization (CNV) in either eye. The second study included patients who had GA with no CNV in the study eye and either CNV±GA in the fellow eye (n=168) or no CNV/GA in the fellow eye (fellow eye intermediate AMD cohort, n=32). All participants were at least 50 years old.

The team analyzed changes in visual function and imaging/anatomic parameters, including change in GA area from baseline and best-corrected visual acuity (BCVA).

At 24 months, the investigators discovered that the adjusted mean change in GA lesion area from baseline was 3.87mm2 in participants with bilateral GA, 3.55mm2 in the fellow eye CNV cohort and 2.96mm2 in the fellow eye intermediate AMD cohort. They noted that GA progression was greater in patients with baseline non-subfoveal GA lesions and increased as baseline low-luminance deficit increased. The study authors observed conversion to GA in 30% and to CNV in 6.7% of the fellow eye in the AMD cohort at month 12. They added that adjusted mean changes in BCVA and low-luminance visual acuity in the study eye from baseline to 24 months were -13.88 and -7.64 in the bilateral GA group, -9.49 and -7.57 in the fellow eye CNV cohort and -11.48 and -8.37 in the AMD cohort, respectively. 

Holekamp N, Wykoff CC, Schmitz-Valckenberg S, et al. Natural history of geographic atrophy secondary to age-related macular degeneration: results from the prospective Proxima A and B clinical trials. Ophthalmology. December 14, 2019. [Epub ahead of print].