Docosahexaenoic and Arachidonic Acid Influence on Preterm Baboon Retinal Composition and Function

Abstract

Dietary n-3 polyunsaturated fatty acid deficiency and prematurity are both associated with suboptimal visual function in nonhuman primates and in humans. This study reports measurements of retinal long chain polyunsaturate (LCP) concentrations and electroretinogram (ERG) parameters for term and preterm neonatal baboons consuming clinically relevant diets. ERGs and retinal fatty acid compositions were obtained from baboon neonates in four groups: term-delivered/breast-fed (B), term/formula-fed (T-), preterm/formula-fed (P-), and preterm/formula (P+) supplemented with long chain polyunsaturates. Initial a-wave slope change (ä), a-wave amplitude (a(amp)) and implicit time (a(i)), and b-wave amplitude (b(amp)) and implicit time (b(i)) were determined and correlations to retinal fatty acid concentrations were evaluated. The P+ group ä and b(amp) significantly improved between 0 and 4 weeks' adjusted age, whereas no P- group parameter improved with age. At four weeks, both a(amp) and b(amp) were significantly greater in group B than in all other groups, and ä and a(i) were greater for P+ than for P-. Concentrations of 22:6n-3, 22:5n-3, and Sigman-3 and the 22:5n-6/22:6n-3 ratio correlated positively with improved retinal response parameters, whereas 22:5n-6, 22:4n-6, 20:4n-6, 20:3n-6, 20:2n-9, 20:1n-9, and 18:1n-9 all correlated negatively (P < 0.05); saturates were uncorrelated. The parameters most linearly related to retinal 22:6n-3 were ä, a(i), and a(amp). Retinal 20:4n-6 concentrations were not influenced by prematurity or supplementation. Breast-feeding optimizes retinal response in 4-week-old baboons. Formula supplemented with 22:6n-3 prevents a decrease in retinal 22:6n-3 and improves preterm ERG parameters compared with unsupplemented formula. Retinal 22:6n-3 status is most closely associated with a-wave parameters.