Lipid modifying drug found to protect diabetic eye

A lipid modifying agent has been shown to significantly reduce the need for laser treatment in diabetic retinopathy, according to a study published in The Lancet and presented during the American Heart Association meeting in Orlando, Florida, US.

"We now hope that we can intervene to significantly reduce the progression of retinopathy before it requires laser treatment," said the principal investigator Anthony Keech, University of Sydney, Australia, adding that the study is likely to lead to changes in the way patients with diabetes are managed.

The Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study, designed primarily to look at cardiovascular events, randomized 9,795 patients with type 2 diabetes to receive fenofibrate 200 mg/day (n=4,895) or placebo (n=4,900). At each of the 63 participating clinics in Australia, New Zealand and Finland, information was also collected on laser treatments for diabetic retinopathy. Additionally, a pre-specified ophthalmology sub-study looked at the effect of fenofibrate on the progression of diabetic retinopathy in 1,012 patients undergoing repeated retinal photography.

The results showed that treatment with fenofibrate reduced the overall risk of a first laser treatment from 4.9% in the placebo group to 3.4% in the treatment group (p=0.0002). The reduction for maculopathy was 31% (p=0.002) and for proliferative retinopathy 30% (p=0.015).

Additionally, the sub-study of 1,012 patients who had regular retinal photographs taken and graded during the study, showed that progression of retinopathy grade by two steps occurred at a similar rate in active- and placebo-treatment groups. However, among patients who had established retinopathy at the study start, significantly fewer fenofibrate (three cases, 3.1%) than placebo-treated patients (14 cases, 14.6%) had two-step progression (p=0.004). The protective effects began after only eight months of treatment and increased throughout the five-year treatment period.

The rationale behind the diabetic retinopathy analysis of the FIELD study was that elevated lipid levels in the systemic circulation constituted a risk factor for diabetic retinopathy. However, fenofibrate did not lead to clinically significant variations in HDL-cholesterol concentrations when compared with placebo. The benefits, the investigators now believe, go beyond the drug's effect on lipid concentrations, and instead fenofibrate may have anti'apoptotic, anti-inflammatory and anti-oxidative effects.

"Identifying these mechanisms paves the way for a whole new avenue of eye treatment," said Paul Mitchell, a study investigator from Westmead Hospital, Sydney, Australia.

In an editorial accompanying the Lancet report, Rafael Simo MD and Cristina Hernandez MD of Vall d'Hebon University Hospital, Barcelona, Spain, criticize the lack of a standard definition for laser treatment and the relatively small number of total events in the trial. "The mechanisms by which fenofibrate exerts its reported benefits are far from being elucidated," they said.