Refraction and Strabismus Evaluation in Preterm Infants With and Without Retinopathy of Prematurity

Abstract

Purpose: : To investigate cycloplegic refraction and ocular alignment in a population of preterm infants at one and six years old with regard to birth weight (BW) and gestational age (GA).

Methods: : We considered 261 preterm infants with BW of 1500gr or less and/or GA of 32 weeks or less. We evaluated visual refraction and ocular alignment records on each patient at the age of one and six years. We considered retinopathy of prematurity (ROP) stage I and II as mild ROP and higher ROP stages as severe ROP. We identified three groups of patients: 217 infants (434 eyes) without evidence of ROP (Group 1: control group), 28 infants (56 eyes) with mild ROP (Group 2) and 16 infants (32 eyes) affected by severe ROP (Group 3). T Student test was performed at the end of the study to compare data.

Results: : The incidence of visual refraction and ocular alignment at the age of one year old in Group 2 and 3 compared to control Group 1 was respectively: emmetropia 1.9% (Group 2) and 5% (Group 3) vs 4% (Group 1); myopia 17.3% (p=0.001) and 39% (p=0.002) vs 5%; hypermetropia 27.8% and 19% vs 37%; astigmatism 45% and 37% vs 54%; strabismus 11.5% (p=0.001) and 38% (p=0.002) vs 5.3%. The incidence of visual refraction and ocular alignment at the age of six years old was respectively: emmetropia 2% and 6% vs 4.5%; myopia 10.7% (p=0.003) and 25% (p=0.001) vs 5.5%; hypermetropia 46.4% and 40.6% vs 60.08%; astigmatism 39.2% and 28.1% vs 29% and strabismus 25% (p=0.003) and 56.25% (p=0.003) vs 11.5%.

Conclusions: : Myopia and strabismus had a significative high incidence at one and six years follow up Groups 2 and 3 compared to control Group 1. The risk of these disorders increases significantly (p<0.05) with the severity of ROP (Group 2 and Group 3 vs Group 1). These data underline the importance of a correct diagnosis and follow up of myopia and strabismus to prevent amblyopia and visual impairment in adulthood. Our data confirm and better underline at six years follow up what we have already showed in our previous study (ARVO 2006, 5299-B714) at one year follow up.

Keywords: retinopathy of prematurity • strabismus • amblyopia