ω-3 Intake and Visual Acuity in Patients With Retinitis Pigmentosa Receiving Vitamin A

Objective: To evaluate whether a diet high in long-chain omega-3 fatty acids can slow the rate of visual acuity loss among patients with retinitis pigmentosa receiving vitamin A palmitate. Methods: We calculated dietary intake from questionnaires completed annually by 357 adult patients from 3 randomized trials who were all receiving vitamin A, 15 000 IU/d, for 4 to 6 years. Rates of visual acuity decline were compared between those with high (>= 0.20 g/d) vs low (<0.20 g/d) omega-3 intake. Analyses took age into account. Results: Mean rates of decline of acuity were slower among those with high omega-3 intake: Early Treatment Diabetic Retinopathy Study distance acuity: high intake=0.59 letter per year, low intake=1.00 letter per year, P=.001; Snellen retinal acuity: high intake=1.5% per year, low intake=2.8% per year, P=.03. Conclusions: We conclude that mean annual rates of decline in distance and retinal visual acuities in adults with retinitis pigmentosa receiving vitamin A, 15 000 IU/d, are slower over 4 to 6 years among those consuming a diet rich in omega-3 fatty acids. To our knowledge, this is the first report that nutritional intake can modify the rate of decline of visual acuity in retinitis pigmentosa.