(HealthDay News) – For patients with typical retinitis pigmentosa, treatment with vitamin A combined with an omega-3-rich diet slows the decline in distance and retinal visual acuities, according to a study published online Feb. 13 in the Archives of Ophthalmology.
Eliot L. Berson, MD, of the Harvard Medical School in Boston, and colleagues analyzed visual acuity data from three clinical trials involving a total of 357 adult patients with typical retinitis pigmentosa who took 15,000IU/d of vitamin A palmitate for 4–6 years. Results were stratified according to whether omega-3 fatty acid intake was high (≥0.20g/d) or low (<0.20g/d), and results were adjusted for age.
The researchers found that the mean rates of decline for both distance and retinal acuities were significantly slower for patients with a high intake versus a low intake of omega-3 fatty acids. Distance acuity decline was 0.59 letters per year compared with 1 letters per year for high and low omega-3 intake, respectively. Retinal acuity decline was 1.5% per year in those with a high omega-3 intake versus 2.8% per year in those with a low omega-3 intake.
“Therefore, the treatment regimen of vitamin A combined with an omega-3-rich diet (≥0.20 g/d) should make it possible for many patients with typical retinitis pigmentosa to retain both visual acuity and central visual field for most of their lives,” the authors write.