Abstract
Purpose:
The NAT2 (Nutritional AMD treatment-2) study was a randomized, placebo-controlled, double-blind, parallel, comparative study. Our purpose was to evaluate the efficacy of docosahexaenoic acid (DHA) enriched oral supplementation in preventing exudative age-related macular degeneration (AMD). Here we correlated the red blood cells membrane (RBCM) levels in omega-3 and the occurrence of choroidal neovascularisation (CNV)
Methods:
263 patients with early lesions of age-related maculopathy and visual acuity better than 0.4 LogMAR units in the study eye and neovascular AMD in the fellow-eye. Patients were randomly assigned to receive either 840 mg/day DHA and 270 mg/day eicosapentaenoic acid (EPA) from fish oil capsules or the placebo (olive oil capsules) for 3 years.
Results:
Time to occurrence and incidence of CNV in the study eye were not significantly different between the DHA (19.5 ± 10.9 months, 28.4%, respectively) and placebo groups (18.7 ± 10.6 months, 25.6%, respectively). EPA+DHA level significantly increased in RBCM in the DHA group (+70%; p<0.001), suggesting that DHA easily penetrated cells, but unexpectedly also in the placebo group (+9%; p=0.007). We observed a wide range of EPA+EPA levels at month 6 and year 3 in both placebo and DHA groups. In the DHA-allocated group, patients steadily achieving the highest tertile of EPA+DHA levels in RBCM had significantly lower risk (-68%; p=0.047; HR=0.32 (0.10-0.99) of developing CNV over 3 years).
Conclusions:
In patients with unilateral exudative AMD, 3 years of oral DHA-enriched supplementation had the same effect on CNV incidence in the second eye as did the placebo. However, the RBCM measurements revealed that CNV incidence was significantly reduced in DHA-supplemented patients showing steadily high EPA+DHA index over 3 years.
Keywords: 412 age-related macular degeneration •
466 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials •
424 antioxidants