Refractive Status in Low Birth Weight 4 to 6-Year-Old Children with or without Retinopathy of Prematurity

Premature birth is common worldwide and can affect the development of brain structures, such as the optic nerve. Eye diseases are very common in low birth weight children and premature children. Vision defects associated with premature birth include Retinopathy of premature babies (ROP), decreased visual acuity, strabismus, amblyopia, and various types of refractive errors. Studies have shown that the occurrence of myopia in children born prematurely is negatively correlated with gestational age and birth weight and is directly related to the severity of retinopathy of prematurity(ROP). Advances in neonatal intensive care unit services have led to a significant increase in the survival rate of premature infants and subsequent medical problems in these children. This study was designed to determine the prevalence of refractive errors in 4-6-year-old children born with a birth weight of less than 2000 grams and gestational age of less than 34 weeks and normal children admitted to the neonatal department of Bou-Ali Sina Hospital in Sari in 2016-2018.

This study was a cross-sectional descriptive study on 43 children aged 4-6 years who were born with a weight of less than 2000 grams and gestational age of less than 34 weeks, and 17 normal children who were admitted in the neonatal department of Bou-Ali Sina Hospital due to neonatal jaundice. The study subjects were in four groups: 12 subjects in group A (ROP cases without injection), 14 subjects in group B (ROP cases with injection), 17 subjects in group C (cases with birth weight less than 2000 grams and gestational age less than 34 weeks without ROP), and 17 normal subjects in group D. Uncorrected distance visual acuity was measured using E-chart. Dry and cyclo refraction (using cyclopentolate 1%) were measured using an autorefractometer. Finally, the fundus was examined using a biomicroscope and 90 diopter lens. Statistical analysis was performed using SPSS software, version 26.

of the 60 studied subjects, 46.67% were females and 53.33% were males, and there was no significant difference in the prevalence of the two sexes between the groups (P=0.146). In total, 12.1% of the studied subjects were myopie, 34.5% were emmetrope, and 53/4% were hypermetrope. Although the prevalence of hypermetropia was higher than other types of refractive errors in all groups, the prevalence of myopia was higher in those with ROP than in groups without ROP, and there was a significant difference in the prevalence of refractive errors in different groups (P=0.025). There was no significant difference between the prevalence of the different types of astigmatism in the studied groups (P=0.304) and with the rule astigmatism was the most common type among all groups. There was a significant and direct relationship between gestational age and birth weight with cyclo-equivalent sphere, which means that the lesser gestational age (P=0.356, r=0.006) and birth weight (P=0.002, r=0.387), the higher the probability of myopia.

Considering the higher prevalence of myopia in low birth weight children, especially in children with ROP, it is necessary to formulate a regular program to screen this category of children to prevent refractive errors, especially myopia in the future.