Statin use doesn't appear to increase AMD risk. Photo: Getty Images.

Age-related macular degeneration (AMD) shares a number of risk factors with atherosclerosis, such as obesity, smoking and cardiovascular disease. Researchers recently investigated whether statins, lipid-lowering agents used to treat atherosclerosis, may also have some protective effect against AMD. The meta-analysis, however, suggested statins have no influence on the subsequent development of choroidal neovascularization or geographic atrophy in AMD patients.

The researchers searched three databases and the reference lists of the included studies that measured risk of AMD development or progression with statin use. A total of 21 articles (including one randomized controlled trial and 20 observational studies) reporting on 1,460,989 patients were included. Pooled risk ratios for statin use associated with any, early and late AMD incidence were 1.05, 0.99 and 1.15, respectively. The authors also noted that in those with existing AMD, the risk ratios for statin use in terms of incidence of progression, choroidal neovascularization and geographic atrophy were 1.04, 0.99 and 0.84, respectively. None were significant.

“The theorized role of statins in the prevention of AMD arises from its anti-inflammatory, anti-angiogenic and lipid-lowering effects,” the authors stated in their paper. “However, we didn’t find a protective or detrimental effect of statin use for the development and progression of AMD.”

They did note, however, that their subgroup analyses found statins significantly reduced the risk for overall AMD incidence in cross-sectional studies and significantly increased the risk of late AMD incidence in cohort studies. They attributed the different effects in the cohort studies for late AMD incidence to the heterogeneity of the two largest studies they included in their analysis.

Their review was limited by the majority of observational studies, which included cross-sectional studies, cohort studies and case series. They noted that most studies adjusted for confounding variables such as age and hypertension. Five of the 21 studies didn’t adjust for pre-existing comorbidities, while two adjusted for one medical comorbidity and 14 adjusted for more than one comorbidity. Patients also tended to be young, and studies tended to have short follow-up periods.

The authors concluded that the relationship between statin use and AMD incidence or progression wasn’t statistically significant. “These findings were supported by a low-moderate quality of evidence and should be interpreted with caution,” they added. “Future studies should aim to investigate the long-term effects of statin use on AMD incidence and progression and to assess whether lipid levels moderate the effect.”