Refractive error in preterm infants without retinopathy of prematurity aged 1-18 months: A propensity score matching analysis.

BACKGROUND

Preterm birth is associated with an increased risk of abnormal refractive development, even without retinopathy of prematurity (ROP). This study aimed to evaluate the differences in refractive error between preterm infants without ROP and full-term infants, as well as to assess the relationship between physical parameters at birth and refractive status in preterm infants.

METHODS

A total of 1205 infants aged 1-18 months participated in this cross-sectional study conducted at Tianjin Women's and Children's Health Center in China from March 2020 to September 2023. Following One-to-one propensity score matching (PSM), 230 pairs of infants were included. Refraction was examined by cycloplegic refraction, and the mean spherical equivalent (MSE) of both eyes was analyzed. A simple linear regression model was employed to determine the relationships between refractive state and gestational age (GA), birth weight (BW), and birth length (BL) in preterm infants.

RESULTS

Among the 1205 infants, 230 were preterm infants without ROP, and 975 were full-term infants. After PSM, the MSE of preterm infants was lower than that of full-term infants during every period (t = -0.320, P = 0.749). Compared with full-term infants, preterm infants exhibited a significantly higher prevalence of refractive error (P = 0.014), particularly astigmatism (P = 0.040). Although the difference in myopia between the two groups was not significant (P = 0.500), preterm infants had more frequent emmetropia than full-term infants across all stages (P = 0.037). In addition, MSE was negatively correlated with both BW and BL (R = 0.260, P < 0.001; R = 0.035, P = 0.004); however, there was no correlation between MSE and GA (R = 0.048, P = 0.051).

CONCLUSIONS

Compared to full-term infants, preterm infants without ROP exhibit lower MSE values and a higher prevalence of refractive errors, particularly astigmatism, and a trend towards developing myopia was observed during early life. BW can be utilized as a parameter to predict the early refractive status of these preterm infants.