The effect of docosahexaenoic acid on the electroretinogram of the guinea pig

AbstractDocosahexaenoic acid (DHA), an n‐3 polyunsaturated fatty acid, is found in consistently high concentrations in the retinae of mammals, yet its role in vision remains unclear. In this study, a mammalian model of variable retinal DHA concentration has been developed, such that the retinal phospholipids of guinea pigs contained between 2.5 and 30.8% DHA. Visual function was assessed using full‐field flash electroretinography, over a range of exposure levels spanning six log units. Trend analysis indicated that retinal function was altered by the tissue DHA level, and was described by a second‐order polynomial “inverted U‐shaped” function. The results suggested that although some amount of DHA is essential for normal retinal function increases in the DHA level past an optimal amount, found to be 19%, provided diminishing returns. In this study, manipulation of the retinal DHA level accounted for 21–35% of the electroretinographic variability.