Statin use appears not to protect against CNV or GA in AMD patients

October 1, 2007

Statin use does not appear to have a significant protective effect against choroidal neovascularization or geographic atrophy in patients with age-related macular degeneration, according to a recent analysis of data collected during the Complications of Age-related Macular Degeneration Prevention Trial.

Key Points

Rochester, MN-Data from a large study indicate that statin use is not protective in a statistically significant way against choroidal neovascularization (CNV), geographic atrophy (GA), or progression of age-related macular degeneration (AMD). A trend toward protection against GA was seen, however, as was a slightly increased risk of development of CNV, according to Colin A. McCannel, MD, assistant professor of ophthalmology, Mayo Clinic, Rochester, MN.

Dr. McCannel presented data stemming from the Complications of Age-related Macular Degeneration Prevention Trial (CAPT), which was a multicenter, randomized, prospective trial to assess whether treating drusen by laser photocoagulation reduces the risk of loss of visual acuity in patients with AMD. Investigators subsequently analyzed data accumulated during CAPT to assess the impact of statin use.

The cholesterol-lowering action of statins may have an effect directly on drusen, because drusen contain cholesterol, Dr. McCannel said. And because cardiovascular disease has a variable association with AMD progression, reducing the risk of cardiovascular disease via cholesterol-lowering statins may have an indirect effect on AMD.

Inflammation has been implicated as an important factor in the development and progression of AMD, thus the inflammation-reducing effects of statins may be beneficial, he continued. Improvement in endothelial cell function may affect the choriocapillaris and its ability to deal with some of the pathologic changes of AMD.

For all of these reasons, the CAPT study group analyzed data from the trial to assess the effect of statins on AMD progression. Between 1999 and 2001, the study enrolled 1,052 participants with 10 or more large drusen (>125 μm) and visual acuity >20/40 in each eye. One eye was randomly assigned to laser treatment and the fellow eye was assigned to observation.

Patients who had their final CAPT visit after May 2005 were asked about their history of use of cholesterol-lowering drugs, including statins. Among 744 patients who provided a medication-use history, 86 (11.6%) said they had begun using statins before enrolling in CAPT, 28 (3.8%) reported beginning in the same year as CAPT, 182 (24.5%) said they started during the study, and 448 (60.2%) reported never using statins.

Investigators used a Cox proportional hazard model in which statin use was a time-dependent covariate in the survival analysis. In the multivariate analysis, adjustments were made for age, cigarette smoking, hypertension, and baseline hyper- pigmentation changes.

Two analyses were performed:

The analysis was repeated for restricted groups, such as patients who had been taking statins throughout the CAPT study or had never used statins.

No statistically significant difference was found between statin users and nonusers for patient characteristics such as age, gender, race, cigarette smoking, or hypertension, although a trend toward significance was seen in the gender category. Similarly, no significant differences were seen between users and nonusers in eye characteristics, including hyperpigmentation, percent of global area covered by drusen, or RPE pigmentation.

CNV developed in 176 patients (23.7%), GA in 80 (10.8%), and late AMD in 242 (25%). Both CNV and GA could occur in the same patient.