A randomized, placebo-controlled clinical trial of docoahexaenoic acid upplementation for X-linked retiniti pigmentoa

Purpoe Low docoahexaenoic acid (DHA) in X-linked retiniti pigmentoa (XLRP) may influence retinal function. The goal of thi tudy were to elevate blood DHA level and determine the effect on the rate of dieae progreion. Deign In a 4-year propective randomized clinical trial, male patient with XLRP (mean age = 16 year; range = 4–38 year) received DHA (400 mg/d; n = 23; +DHA group) or placebo (n = 21) capule. Method Red blood cell (RBC)-DHA concentration were aeed every 6 month. Full-field cone electroretinogram (ERG; the primary outcome meaure), viual acuity, dark-adaptation, viual field, rod ERG, and fundu photo were recorded annually. Reult In the +DHA group, RBC-DHA increaed 2.5-fold over placebo level (70 v 28 mg DHA/l). Repeated meaure analyi of variance for cone ERG howed a ignificant main effect of year (P < .0001) but not of group (P = .16). Preervation of cone ERG function correlated with RBC-DHA (P = .018), and there wa le change in fundu appearance in the +DHA group (P = .04). Neither viual acuity nor viual field were changed. In ubet analyi, DHA upplementation wa beneficial in reducing rod ERG functional lo in patient aged <12 year (P = .040) and preerving cone ERG function in patient ≥12 year (P = .038). Concluion Although DHA-upplemented patient had ignificantly elevated mean RBC-DHA level, the rate of cone ERG functional lo wa not ignificantly different between group. upplemental analye provided evidence for a DHA benefit and a direction for ubequent invetigation.