Amblyopia Risk Factors in Premature Children in the First 3 Years of Life

Purpose: To determine the incidence of amblyopia risk factors during the first 3 years of life in premature children. Methods: This prospective cohort included 145 premature children (gestational age of less than 37 weeks) who were evaluated for amblyopia risk factors every 6 months until age 3 years. The incidence rate, cumulative incidence, and prevalence of any amblyopia risk factor were assessed in retinopathy of prematurity (ROP) and non-ROP screened groups. Multivariate logistic regression was performed to evaluate variables associated with the development of an amblyopia risk factor. Results: The 3-year incidence rates of amblyopia risk factors were similar between the non-ROP and ROP screened groups (18 versus 19 cases per 1,000 person-years, respectively). The 3-year cumulative incidence was also similar: 32% (95% confidence interval [CI]: 18 to 47) in the non-ROP and 14% (95% CI: 5 to 28) in the ROP screened group (P > .05). In the ROP screened group, the prevalence rates were 20% or greater at most time points. In the non-ROP screened group, the prevalence rates were 11% to 14% during the first 18 months and increased to more than 20% at 24 months and thereafter. Astigmatism was the most prevalent amblyopia risk factor in both groups (7% to 18%). Conclusions: The incidence of amblyopia risk factors was not significantly different between non-ROP and ROP screened children in our cohort. The prevalence of refractive errors among premature non-ROP screened children was higher than that reported in childhood in the literature. It may be appropriate to screen all children with a history of prematurity for refractive errors around 24 months of age.