Impact of early infant feeding patterns on visual maturation and retinal development: an electrophysiological study

Abstract Objective Human milk is rich in bioactive nutrients essential for retinal development and visual maturation. Despite advances in the manufacture of formula milk to better simulate human milk, low-resource countries still rely on standard formula milk due its lower financial cost. Aim To assess visual function and retinal development in exclusively breastfed versus standard formula-fed healthy full-term infants aged 4 to 6 months. Subjects and methods This cross-sectional comparative study included 55 full-term infants aged 4 to 6 months; 25 were exclusively breastfed and 30 were standard formula-fed infants. Visual function and retinal development were examined using flash visual evoked potential (F-VEP) and flash electroretinogram (F-ERG). Results breastfed infants had significantly shorter F-VEP latency (123.68 ± 18.44 versus 150.63 ± 30.81; p-value 0.004) and higher amplitude of P2 wave (30.64 ± 23.94 versus 9.23 ± 9.95; p -value < 0.001) than formula-fed infants. Additionally, F-ERG a and b waves’ amplitudes were significantly higher in breastfed than formula-fed infants (11.96 ± 4.82 versus 8.00 ± 1.93; p-value 0.001 for a wave and 27.62 ± 10.58 versus 19.21 ± 6.81; p -value 0.003 for b wave). Effect size analysis showed a large difference in F-VEP parameters and F-ERG amplitudes between breastfed and formula-fed infants. Apart from significantly higher weight in breastfed than formula-fed infants, no significant difference was observed between both groups as regards socioeconomic and demographic characteristics. Conclusion Exclusive breastfeeding was associated with electrophysiological differences suggestive of more favorable retinal function and visual pathway maturation in early infancy.