ω-3 intake and visual acuity in patients with retinitis pigmentosa receiving vitamin A

Abstract

Objective: To evaluate whether a diet high in long chain ω-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) ω-3 intake. Analyses took age into account.

Results: Mean rates of decline of acuity were slower among those with high ω-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 ω-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.

Figure 1

Mean log rates of decline of distance and retinal visual acuity for patients with high dietary omega-3 intake versus low dietary omega-3 intake. Data represent means and standard errors.

Figure 2

Mean log rates of decline of distance and retinal visual acuity for patients by quartile of dietary omega-3 intake in g/d: quartile 1: 0.002–0.138; quartile 2: 0.139–0.237; quartile 3: 0.237–0.382; quartile 4: 0.388–1.243. Data represent means and standard errors.