Treatment trial for retinitis pigmentosa

We conducted a randomized, controlled, double-masked trial to determine whether supplements of vitamin A or vitamin E alone or in combination affect the course of retinitis pigmentosa. We found that the course of retinal degeneration as monitored by the ERG was slower on average among adult patients taking a supplement of 15,000 IU/day of vitamin A in the palmitate form, whereas the course appeared to be hastened by supplementation with 400 IU/day of vitamin E.