Sixteen trials involving 1,949 infants were included in the review.
Ten trials (852 infants) evaluated visual acuity by using visual evoked potential methods. There was a significant positive effect of long-chain polyunsaturated fatty acid supplementation on infant visual resolution acuity for all three time points (at two months for term infants WMD -0.08, 95%CI -0.14 to -0.03; Ι²=76%: at four months for term and preterm infants WMD -0.07, 95% CI -0.13 to -0.02; Ι²=78%: and at 12 months for term infants only WMD -0.11, 95% CI -0.20 to -0.03; Ι²=92%).
Twelve trials (1,095 infants) evaluated visual acuity by using behavioural methods. A combined analyses of term and preterm infants showed a significant effect of long-chain polyunsaturated fatty acid supplementation on infant visual resolution acuity at the age of two months (WMD -0.08, 95% CI -0.14 to -0.02; Ι²= 71%) but not at four or 12 months.
The subgroup analyses showed that long-chain polyunsaturated fatty acid supplementation did not have any significant impact on preterm infant visual resolution acuity assessed by both visual evoked potential and behavioural method.
The results of sensitivity and meta-regression analyses were reported in the paper.
There was no evidence of publication bias.