NEI Clinical Studies

Randomized Trial for Retinitis Pigmentosa

Purpose | Background | Description | Patient Eligibility | Recruitment Status | Current Status | Results | Publications | Resource Centers | NEI Representative

Purpose

To determine whether a nutritional supplement in addition to vitamin A will slow the course of retinitis pigmentosa.

Background

Retinitis pigmentosa (RP) is a group of inherited retinal degenerations with a worldwide prevalence of approximately 1 in 4,000. Patients typically report night blindness and difficulty with midperipheral visual field in adolescence. As the condition progresses, they lose far peripheral visual field. Most patients have reductions in central vision by age 50 to 80 years. Based on electroretinograms (ERGs), the course of the disease can be slowed on average among adults on 15,000 IU/day of vitamin A palmitate. While conducting the trial on the effects of vitamin A on RP, it became apparent that another substance in the diet could be affecting the course of the disease. This prompted the present randomized, controlled trial.

Description

This study is a randomized, controlled, double-masked trial with a planned duration of 5 years. Patients with the common forms of RP are assigned to either a test or a control group. All receive 15,000 IU/day of vitamin A palmitate in addition to the capsules under study. Participants will not know the contents of the supplement or the group to which they have been assigned until the end of the trial. The main outcome measurement is the total point score on the Humphrey Field Analyzer (HFA). In addition, computer-averaged 30-Hz cone ERG amplitudes and visual acuity are measured annually.

Patient Eligibility

Eligible patients must be between the ages of 18 and 56, be able to see the entire face of someone sitting across the table from them without scanning, read newspaper-size print without special magnifying aids, and walk unaided in daylight. In addition, participants must have a normal fasting serum vitamin A and normal liver function profile, be in good general health, and reside in the United States. Women who are pregnant or planning to become pregnant cannot be included because of the risk of birth defects that could occur while they are on a vitamin A supplement.

Patient Recruitment Status

Recruitment began in May 1996 and was completed in September 1997.

Current Status of Study

Ongoing.

Results

None. It has been hypothesized that the capsules under study could provide additional years of useful vision for the average patient with RP. This beneficial effect would be expected to be additive to the estimated 7 additional years of vision provided by vitamin A when started at age 32.

Publications

None.

Clinical Centers

Eliot L. Berson, M.D., Ophthalmologist
Ernst J. Schaefer, M.D., Internist
Berman-Gund Laboratory for the Study of Retinal Degenerations
Harvard Medical School
Massachusetts Eye and Ear Infirmary
243 Charles Street
Boston, MA 02114
Telephone: (617) 573-3600
Fax: (617) 573-3216

Resource Centers

Robert J. Brockhurst, M.D., Ophthalmologist
Alexander R. Gaudio, M.D., Ophthalmologist
Bernard Rosner, Ph.D., Statistician
Michael A. Sandberg, Ph.D., Perimetrist/Electrophysiologist
K.C. Hayes, D.V.M., Ph.D., Nutritional Biochemist
Carol Weigel-DiFranco, Data Manager
Walter Willett, M.D., Nutritional Epidemiologist
Chris A. Johnson, Ph.D., Consulting Perimetrist
Berman-Gund Laboratory for the Study of Retinal Degenerations
Harvard Medical School
Massachusetts Eye and Ear Infirmary
243 Charles Street
Boston, MA 02114
Telephone: (617) 573-3600
Fax: (617) 573-3216

NEI Representative

Natalie Kurinij, Ph.D.
National Eye Institute
National Institutes of Health
Executive Plaza South, Suite 350
6120 Executive Boulevard, MSC 7164
Bethesda, MD 20892-7164
Telephone: (301) 496-5983
Fax: (301) 402-0528

Data and Safety Monitoring Committee

George Bresnick, M.D.
University of Rochester
Rochester, NY

Baruch Brody, Ph.D.
Baylor College of Medicine
Houston, TX

Barry Davis, M.D., Ph.D.
University of Texas
Houston, TX

Carol Mangione, M.D.
University of California at Los Angeles
Los Angeles, CA

James A. Olson, Ph.D.
Iowa State University
Ames, IA

Sander J. Robins, M.D.
Veterans Administration Medical Center
Boston, MA

Pamela Sample, Ph.D.
University of California at San Diego
LaJolla, CA

Natalie Kurinij, Ph.D. (ex officio)
National Eye Institute
Bethesda, MD

Marian R. Fisher, Ph.D., Chair
University of Wisconsin
Madison, WI

Last Updated: 9/22/99