Effect of docosahexaenoic acid supplementation on the macular function of patients with Best vitelliform macular dystrophy: randomized clinical trial.
OBJECTIVE
Best disease is a slowly progressive macular dystrophy that typically has an onset in early childhood. Multiple lines of evidence suggest that dietary docosahexaenoic acid (DHA) protects against the development of macular degeneration. Our trial tested the effect of an oral supplement of DHA on visual function in patients with Best disease.


METHODS
Double-masked, randomized, placebo-controlled, crossover clinical trial.


METHODS
Eight patients with Best disease.


METHODS
Patients were given either an oral supplement of DHA (20 mg/kg daily) or placebo. Primary outcome measures were the multifocal electroretinogram (mfERG) and electro-oculogram (EOG). Plasma DHA was tracked along with visual acuity (Early Treatment Diabetic Retinopathy Study chart), VF-14 scores, and Humphrey visual fields.


RESULTS
All 8 patients had increased plasma DHA levels (2-3 fold) during periods of DHA supplementation compared with periods without supplementation. Differences in visual acuity, VF-14 scores, and EOG Arden ratios during periods with and without DHA supplementation were all statistically insignificant. A positive correlation was found between the plasma concentration of DHA and mfERG amplitudes, but amplitude changes during the treatment periods were not significant. A carryover effect of DHA supplementation was a confounding error.


CONCLUSIONS
Our pilot trial of DHA supplementation in 8 patients with Best disease did not demonstrate an improvement in macular function. An expanded trial would be needed to examine the full effects of DHA supplementation on visual function in Best disease.
Lee
Thomas K M
TK
Department of Ophthalmology, University of Alberta, Edmonton, Alta.
Clandinin
M Thomas
MT
Hébert
Marc
M
MacDonald
Ian M
IM
D000328:Adult; D000075002:Bestrophins; D018118:Chloride Channels / Q000235:genetics; D018592:Cross-Over Studies; D004281:Docosahexaenoic Acids / Q000008:administration & dosage* / Q000097:blood; D004311:Double-Blind Method; D004585:Electrooculography; D004596:Electroretinography; D005136:Eye Proteins / Q000235:genetics; D005838:Genotype; D006801:Humans; D008266:Macula Lutea / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012162:Retinal Degeneration / Q000097:blood / Q000235:genetics / Q000503:physiopathology*; D055213:Retinal Pigment Epithelium / Q000473:pathology*; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires; D014792:Visual Acuity; D014794:Visual Fields; D055815:Young Adult
C113133:BEST1 protein, human; D000075002:Bestrophins; D018118:Chloride Channels; D005136:Eye Proteins; D004281:Docosahexaenoic Acids