We already know many of the risks associated with the development of neovascular age-related macular degeneration (AMD), or wet AMD. However, some factors that drive conversion from dry to wet AMD remain elusive, with research limited by population size and study designs that do not incorporate certain imaging modalities and genetic assessment. Researchers sought to fill this gap with a secondary analysis of the HARBOR trial data and discovered that two imaging features (total en face area of drusen restricted to a circular area 3mm from the fovea and mean drusen reflectivity) and one genetic variant (ACAD10 locus) were associated with conversion to neovascular AMD.

This post hoc secondary analysis evaluated 686 fellow eyes with dry AMD at baseline. The team focused on imaging features describing the presence, number, extent, density and relative reflectivity of drusen. Genetic analysis included 34 single-nucleotide polymorphisms. 

Of the 686 fellow eyes included in the analysis, the researchers note that 154 (22.4%) converted to wet AMD, with female sex posing a significant association with conversion. After controlling for demographic and treatment effects, they add that drusen area within 3mm of the fovea and mean drusen reflectivity were significantly associated with conversion to wet AMD as well. In addition, they found that one genetic variant was also associated.

Hallak JA, de Sisternes L, Osborne A. Imaging, genetic, and demographic factors associated with conversion to neovascular age-related macular degeneration. JAMA Ophthalmol. April 25, 2019. [Epub ahead of print].