Statin use appears to be associated with a later age of onset of AMD, particularly in non-Hispanic white and Black individuals, as well as patients with dry AMD. Photo: Getty Images. Click image to enlarge.

Age-related macular degeneration (AMD) accounts for many cases of severe vision loss, and the number of people affected by this condition is only expected to rise. Researchers recently aimed to identify risk factors that could be used to prevent the progression of the disease, zeroing in on its relationship with statin use.

“We focused on the effect of statin use on the age of onset of AMD, rather than simply whether or not individuals develop AMD as a whole,” the authors explained in their paper. “This is a very clinically relevant difference since the significance of a patient who first develops AMD very late in life is much different from a patient who develops AMD at a younger age and has many remaining years over which they may progress to advanced AMD.”

A combined sample size of 62,817 patients were screened, across two sites: 52,850 patients from University of California Los Angeles (UCLA) and 9,977 patients from University of California San Francisco (UCSF).

The study found that 5,498 of 52,840 patients at UCLA were diagnosed with AMD. Statin use and Black and Hispanic ethnicities were associated with a later AMD onset, while female sex, obesity and fluoxetine use were associated with an earlier AMD onset. Statin use was significant among patients with dry AMD but not wet AMD.

In the UCSF cohort, 526 of 9,977 patients had AMD, and there were associations between statins, Black ethnicity and obesity with AMD onset.

Female sex was also associated with an earlier onset of AMD and dry AMD among the larger UCLA dataset, which is consistent with previous studies. The authors noted this is observed when controlling for comorbidities and other documented risk factors, ethnicity and among non-Hispanic white patients.

Several studies have found obesity to be a risk factor for developing late AMD; in this study, the authors found that obesity “significantly hastens the age of onset of AMD, controlling for risk factors, ethnicity and among non-Hispanic white patients.”

“In fact, obesity was the only significant covariate identified among patients with wet AMD, where obesity was found to significantly hasten the age of disease onset,” the authors explained. “This may warrant further studies on the effect of BMI and weight on the age of onset of AMD, especially among non-Hispanic white patients.”

Fluoxetine may place an individual at a decreased lifetime risk for developing non-neovascular AMD. “Our study suggests that when AMD does develop, it may develop earlier in patients using fluoxetine,” the authors noted.

Non-Hispanic white patients evaluated at UCLA were the only ethnic subgroup that experienced a significant protective effect of statins on delaying the onset of AMD. Statins did not have an effect on Black, Hispanic, Asian or Pacific Islander patients at UCLA, which could be attributed to a much higher prevalence of non-Hispanic white patients in the cohort.

Statin use did not have a significant effect on the age of onset of AMD in any of the ethnic subgroups in the UCSF dataset, which could be due to this cohort being less than 20% of the size of the UCLA dataset.

 “Interestingly, when stratifying by dry vs. wet AMD among UCLA patients, we found statin use to be significantly protective only for the dry AMD subgroup,” the authors noted. “This may reflect differences in the protective mechanism of statins on the progression of AMD or could be a consequence of the reduced sample size with stratification and may warrant further study. Rather than viewing AMD from a binary perspective (presence or absence of disease), it is important to consider the factors that may be affecting the onset and progression of AMD.”