When exudative neovascular age-related macular degeneration (nvAMD) develops soon after geographic atrophy (GA), a new study shows that the enlargement of the GA is slowed. This finding indicates that perilesional non-exudative choroidal neovascular tissue may, in some cases, slow the enlargement of smaller GA lesions through improved perfusion, according to researchers.
The same association was not noted in more long-standing GA cases, which have larger lesions. The phenomena could also not be explained by any clinical, imaging, or genetic characteristics in the participants of the study.
Researchers used data from the second Age-Related Eye Disease Study (AREDS2) to evaluate 757 eyes that developed GA on follow-up exams. Of that group, 73 (9.6%) developed exudative nvAMD. The other 684 eyes developed GA but never developed subsequent exudative nvAMD. The 73 that did develop nvAMD saw an enlargement of 0.20 mm a year.
The larger group, which never developed nvAMD, grew at a rate of 0.29 mm per year. AREDS2 also featured data from 456 eyes that had GA at baseline. In 4.1 years of follow up, 63 (13.8%) developed subsequent exudative nvAMD. The GA enlargement in these eyes was similar (0.31 mm/year) compared with the other 393 eyes that did not develop subsequent exudative nvAMD (0.28 mm/year). They followed all patients for a mean follow-up of 2.3 years, examining baseline and annual stereoscopic color fundus photographs, GA presence and area, and exudative nvAMD presence.
In this study, the rate of GA enlargement was variably associated with the subsequent development of exudative nvAMD, depending on whether eyes had GA present at baseline. In the group that developed GA during the AREDS2 study, slower GA enlargement was observed in eyes with subsequent development of exudative nvAMD than those without. However, this was not found in the group who presented to AREDS2 with GA and whose eyes had larger baseline lesion sizes. These findings may be consistent with the idea that the presence of non-exudative macular neovascularization (MNV) near a GA lesion can slow GA enlargement only in its local vicinity.
If these findings are representative of the wider population of eyes with nvAMD, it suggests that the majority of nvAMD cases likely exist as non-exudative MNV for a variable, but potentially prolonged, period before the onset of exudation, according to the researchers.
These results may “help interpret the findings of ongoing clinical trials with a high rate of exudative nvAMD following GA,” the investigators report.
Hwang CK, Agrón E, Domalpally A et al. Progression of geographic atrophy with subsequent exudative neovascular disease in age-related macular degeneration. Published online October 16, 2020. Ophthalmol Retina. doi: 10.1016/j.oret.2020.10.008