Refractive Status and Amblyopia Risk Factors in Premature Infants with Different Gestational Age and Birth Weight

Abstract Objective: To explore amblyopia risk factors in premature infants vs. full term infants, low birth weight(LBW) vs. very low birth weight(VLBW) infants, and moderately/late preterm(PT) vs. very preterm(VPT) infants. Methods: A total of 143 premature infants without retinopathy of prematurity were collected and then grouped according to body weight and gestational age. There were 130 full term infants in the control group. Infants about 1 year of age at risk for amblyopia were selected using Spot Vision Screener. Differences in amblyopia risk factors between full term infants and premature infants, between the LBW group and VLBW group, and between the PT group and VPT group were then analyzed. Results: In terms of refractive status, diopter cylinder(DC) was higher in the premature infants than in full term infants; diopter sphere(DS) and spherical equivalent(SE) was higher in the VPT group than in the PT group. The prevalence of esotropia was higher in premature infants than in full term infants, and in the VPT group than in the PT group. As shown by the analysis, amblyopia risk factors were found in 10.5% premature infants vs. 3.9% full term infants, 4.7% LBW infants vs. 19.0% VLBW infants, and 5.1% PT infants vs. 16.9% VPT infants. All observed differences were statistically significant. Conclusion: Based on the screening results, the incidence rate of amblyopia risk factors was higher in premature infants than in full term infants, and it was highest in both VPT infants and VLBW infants. The major risk factors were astigmatism and esotropia.