Many treatments for age-related macular degeneration (AMD) aren’t implemented until patients progress to neovascular, or “wet,” AMD. But even in the atrophic, or “dry” form, the likelihood of comorbidities is elevated, researchers say in a newly published report in the American Academy of Ophthalmology’s journal Ophthalmology Retina.

In the study, which looked at 16 years’ worth of data, researchers showed geographic atrophy and choroidal neovascularization (CNV) are frequent in eyes with early and intermediate AMD. This data incorporated the records of 40,543 patients across 10 sites across the United Kingdom.

The study also found the status of the fellow eye affects the rate of progression.

Their reporting shows that eyes with early and intermediate AMD and a diagnosis of CNV in the fellow eye progressed to CNV fastest (at a rate of 15.2 per 100 person-years). Those with a diagnosis of geographic atrophy in the fellow eye progressed to geographic atrophy the fastest (at a rate of 11.2 per 100 person-years). Individuals with bilateral early/intermediate AMD had a 2.0 rate of progression to geographic atrophy and 3.2 rate of progression to CNV per 100 person years.

In the multivariate model, age, female sex and cardiovascular disease were associated with an increased risk of progression to advanced AMD, while diabetes and glaucoma were associated with a decreased rate of progression (hazard ratio, 0.45 and 0.64, respectively).