Clinical trial of docosahexaenoic acid in patients with retinitis pigmentosa receiving vitamin A treatment.
OBJECTIVE
To determine whether a therapeutic dose of docosahexaenoic acid (DHA), an omega-3 fatty acid, will slow the course of retinal degeneration in adult patients with retinitis pigmentosa who are also receiving vitamin A.


METHODS
Randomized, controlled, double-masked trial of 221 patients, aged 18 to 55 years, evaluated over a 4-year interval. Patients were given either 1200 mg/d of docosahexaenoic acid or control capsules. All were given 15 000 IU/d of vitamin A (given as retinyl palmitate). Randomization considered genetic type and baseline dietary omega-3 fatty acid intake.


METHODS
The primary outcome measure was the total point score for the 30-2 program of the Humphrey field analyzer; secondary outcome measures were the total point score for the 30-2 and 30/60-1 programs combined, 30-Hz electroretinogram amplitude, and Early Treatment Diabetic Rentinopathy Study visual acuity.


RESULTS
No significant differences in decline in ocular function were found between the docosahexaenoic acid plus vitamin A (DHA + A) group and control plus vitamin A (control + A) group over a 4-year interval among all 221 randomized patients or among the 208 patients who completed all 4 follow-up visits. The mean annual rate of loss of sensitivity for the Humphrey Field Analyzer 30-2 program was 37 dB for the DHA + A group and 38 dB for the control + A group (P =.88). For the Humphrey Field Analyzer 30-2 and 30/60-1 programs combined, the mean annual rates of loss of field sensitivity were 57 dB for the DHA + A group and 60 dB (P =.73) for control + A group. No toxic adverse effects were observed. No significant differences by treatment group assignment were observed within genetic types or within the category of baseline omega-3 fatty acid intake.


CONCLUSIONS
In patients assigned to receive 15 000 IU/d of vitamin A, this randomized trial showed that 1200 mg/d of docosahexaenoic acid supplementation over a 4-year interval did not, on average, slow the course of disease in patients with retinitis pigmentosa.
Berson
Eliot L
EL
Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, 243 Charles Street, Boston, MA 02114, USA.
Rosner
Bernard
B
Sandberg
Michael A
MA
Weigel-DiFranco
Carol
C
Moser
Ann
A
Brockhurst
Robert J
RJ
Hayes
K C
KC
Johnson
Chris A
CA
Anderson
Ellen J
EJ
Gaudio
Alexander R
AR
Willett
Walter C
WC
Schaefer
Ernst J
EJ
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D004281:Docosahexaenoic Acids / Q000627:therapeutic use*; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D004596:Electroretinography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012174:Retinitis Pigmentosa / Q000188:drug therapy* / Q000503:physiopathology; D014786:Vision Disorders / Q000188:drug therapy / Q000503:physiopathology; D014794:Visual Fields / Q000502:physiology; D014810:Vitamin E / Q000627:therapeutic use*
D014810:Vitamin E; D004281:Docosahexaenoic Acids