Abstract
AIMS: This study assessed the prevalence of strabismus, nystagmus and their risk factors in children born preterm, stratified by gestational age (GA), retinopathy of prematurity (ROP) and ROP treatment. METHODS: This is a retrospective cohort study with a prospective follow-up in a large cohort of children born preterm and full-term aged 4-17 years. Multivariable logistic regression analyses assessed associations of strabismus and nystagmus with perinatal parameters. Participants were divided into the following groups: controls born at term (GA ≥37 weeks, group 1), children born preterm without ROP and GA 33-36 weeks (group 2), GA 29-32 weeks (group 3), GA ≤28 weeks (group 4), GA ≤32 weeks with untreated ROP (group 5) and GA ≤32 weeks with treated ROP (group 6). RESULTS: 949 children (11.21±3.92 years, 495 females) were included. Strabismus was observed in 6% of children in group 1, 10% in group 2, 12% in group 3, 23% in group 4, 20% in group 5 and 68% in group 6. Nystagmus was observed in 0.8%, 0.4%, 1.8%, 2.6%, 5.0% and 47% in the respective groups. Strabismus was associated with earlier GA (OR=1.08; p=0.01), astigmatism (OR=2.48; p=0.02) and hypermetropia (OR=2.09; p=0.04). Esotropia was associated with weeks of prematurity (OR=1.11; p=0.02), anisometropia (OR=3.09; p=0.02) and hypermetropia (OR=4.17; p<0.001). Nystagmus was associated with ROP (OR=7.49; p=0.03), anisometropia (OR=5.17; p=0.04) and myopia (OR=11.09; p<0.001). CONCLUSIONS: Strabismus in children is linked to preterm birth and refractive error, while nystagmus is more prevalent in children with ROP and children with refractive errors.