Comment in:

Arch Ophthalmol. 1993 Jun;111(6):751-4.

Arch Ophthalmol. 1993 Nov;111(11):1460-1; author reply 1463-5.

Arch Ophthalmol. 1993 Nov;111(11):1460; author reply 1463-5.

Arch Ophthalmol. 1993 Nov;111(11):1461-2; author reply 1462-5.

Arch Ophthalmol. 1993 Nov;111(11):1462-3.

Arch Ophthalmol. 1993 Nov;111(11):1463; author reply 1463-6.

A randomized trial of vitamin A and vitamin E supplementation for retinitis pigmentosa.

Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston 02114.

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 x 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.

PMID: 8512476 [PubMed - indexed for MEDLINE]