Long chain polyunsaturated fatty acids and visual function in preterm infants

Electroretinograms (ERG) were recorded at 40 weeks post-conceptual age (PCA) in 18 infants born prematurely (25-32 weeks gestation). Fatty acid composition of plasma and red cell phospholipids was measured within 4 days of birth and at time of ERG testing, and detailed record was kept of dietary intake. Correlations were seen between percentage intake of breast milk and docosahexaenoic acid (DHA) in both plasma (r = 0.818, P < 0.0001) and red cells r = 0.534, P = 0.035) and significant differences in fatty acid profiles were seen between infants receiving > 50% and < 50% breast milk. No difference was seen in retinal sensitivity between infants receiving > 50% or < 50% breast milk. A positive correlation was seen between scotopic (rod) b-wave implicit time on ERG and DHA in both plasma (r = 0.733, P = 0.001) and red cells (r = 0.502, P = 0.04). A positive correlation was seen between arachidonic acid and rod ERG amplitude (r = 0.565, P = 0.022) which may reflect the higher AA/DHA ratio in the developing retina. These data did not support our hypothesis that increased dietary DHA results in enhanced retinal maturation. Visual acuity measured at 40 weeks PCA and again 3 months later was similar between groups. While subtle relationships were demonstrated between long chain polyunsaturated fatty acids and visual function, all infants were felt to be within age-appropriate normal range at expected date of delivery and at 3 months corrected age.