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Article
June 1993

A Randomized Trial of Vitamin A and Vitamin E Supplementation for Retinitis Pigmentosa

Author Affiliations

From the Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston.

Arch Ophthalmol. 1993;111(6):761-772. doi:10.1001/archopht.1993.01090060049022
Abstract

• Objective.  —To determine whether supplements of vitamin A or vitamin E alone or in combination affect the course of retinitis pigmentosa.

Design.  —Randomized, controlled, double-masked trial with 2×2 factorial design and duration of 4 to 6 years. Electroretinograms, visual field area, and visual acuity were measured annually.

Setting.  —Clinical research facility.

Patients.  —601 patients aged 18 through 49 years with retinitis pigmentosa meeting preset eligibility criteria. Ninety-five percent of the patients completed the study. There were no adverse reactions.

Intervention.  —Patients were assigned to one of four treatment groups receiving 15 000 IU/d of vitamin A, 15 000 IU/d of vitamin A plus 400 IU/d of vitamin E, trace amounts of both vitamins, or 400 IU/d of vitamin E.

Main Outcome Measure.  —Cone electroretinogram amplitude.

Results.  —The two groups receiving 15 000 IU/d of vitamin A had on average a slower rate of decline of retinal function than the two groups not receiving this dosage (P=.01). Among 354 patients with higher initial amplitudes, the two groups receiving 15 000 IU/d of vitamin A were 32% less likely to have a decline in amplitude of 50% or more from baseline in a given year than those not receiving this dosage (P=.01), while the two groups receiving 400 IU/d of vitamin E were 42% more likely to have a decline in amplitude of 50% or more from baseline than those not receiving this dosage (P=.03). While not statistically significant, similar trends were observed for rates of decline of visual field area. Visual acuity declined about 1 letter per year in all groups.

Conclusions.  —These results support a beneficial effect of 15 000 IU/d of vitamin A and suggest an adverse effect of 400 IU/d of vitamin E on the course of retinitis pigmentosa.

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