Clinical trial of docosahexaenoic acid in patients with retinitis pigmentosa receiving vitamin A treatment

Arch Ophthalmol. 2004 Sep;122(9):1297-305. doi: 10.1001/archopht.122.9.1297.


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.

Design: 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.

Main outcome measures: 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.

Conclusion: 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.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Administration, Oral
  • Adolescent
  • Adult
  • Docosahexaenoic Acids / therapeutic use*
  • Double-Blind Method
  • Drug Therapy, Combination
  • Electroretinography
  • Female
  • Humans
  • Male
  • Middle Aged
  • Pilot Projects
  • Retinitis Pigmentosa / drug therapy*
  • Retinitis Pigmentosa / physiopathology
  • Vision Disorders / drug therapy
  • Vision Disorders / physiopathology
  • Visual Fields / physiology
  • Vitamin E / therapeutic use*


  • Vitamin E
  • Docosahexaenoic Acids