Preterm Infants Fed Fish Oil May Have Less Eye Disease

One of the conditions that preterm infants risk is abnormal retinal development (retinopathy). The chances are greater in infants weighing less than 1,250 grams (2 lb 12 oz) at birth. This disorder results from the abnormal development of blood vessels in the retina. Blood vessel growth requires long-chain polyunsaturated fatty acids (PUFAs), especially DHA, a long-chain omega-3 PUFA. Long-chain omega-3s have been shown to reduce the area of damage and improve healthy blood vessel growth in this condition. We know they are essential to healthy visual function and are especially so in preterm infants. These infants have missed the major transfer of long-chain PUFAs that occurs in the third trimester and have no stores to rely on. Thus, including these fatty acids in their feeding is critical. A study in preterm infants weighing less than 1,250 grams at birth examined the development of retinopathy in infants fed one of two types of preparation. One formula contained long-chain PUFAs enriched in DHA and the other lacked long-chain PUFAs. Infants were also given breast milk or long-chain PUFA-enriched formula as their ability to tolerate it developed. Most infants received their own mother’s breast milk, which would have some long-chain PUFAs. The investigators watched the infants for the development of retinopathy from the third to fourth week of life and continuing thereafter (Figure). They also monitored the infants for liver function difficulties, such as blockage in the flow of bile (cholestasis). This condition is also more likely in preterm than term infants. Retinopathy occurred at a similar rate in both the long-chain PUFA-fed infants and the controls. However, the outcomes differed substantially. Ten of the 13 infants with retinopathy who received fish oil experienced a spontaneous regression of the condition and 3 required laser therapy. In the infants not fed long-chain PUFAs, 12 of the 16 were treated with laser therapy for retinopathy, a significantly higher rate of treatment than the fish oil-fed infants. Visual acuity, assessed at 18 or 24 months of age in the infants who developed retinopathy, was in the normal range for 22 of the 29 infants available for evaluation. The authors suggested that prompt treatment of the condition likely contributed to these encouraging results. None of the infants receiving fish oil developed cholestasis, but 5 of the 44 control infants did. There were too few cases for this difference to be statistically significant. Because the main difference between these two groups of preterm infants was the provision of long-chain PUFAs immediately after birth, the results suggest that these fatty acids are important in reducing the chances of retinopathy in preterm infants and should be incorporated into preterm feedings. They also suggest that aggressive treatment of retinopathy once it is detected may contribute to the normal visual outcomes, as observed in this study. Readers can be reassured that several preterm infant formulas containing DHA and arachidonic acid are available.