Prevalence and course of strabismus in the first year of life for infants with prethreshold retinopathy of prematurity: Findings from the early treatment for retinopathy of prematurity study

Objective: To present strabismus data for premature infants with prethreshold retinopathy of prematurity (ROP) enrolled in the Early Treatment for Retinopathy of Prematurity study. Design: The prevalence of strabismus was tabulated for all of the infants with high-risk prethreshold disease who participated in the randomized trial of the Early Treatment for Retinopathy of Prematurity study and were examined at 6 and/or 9 months' corrected age as well as for all of the infants with low-risk prethreshold disease who were examined at 6 months' corrected age. Main Outcome Measures: Presence or absence of strabismus at 6 and 9 months' corrected age. Results: The prevalence of strabismus at 6 months was higher for infants with high-risk prethreshold ROP than for those with low-risk prethreshold ROP (20.3% vs 9.6%, respectively; P<.001). Risk factors associated with the development of strabismus at 9 months include abnormal fixation behavior, presence of amblyopia, and outborn birth status (ie, born outside of a study-affiliated hospital). At 9 months, 30% of infants with high-risk prethreshold ROP had strabismus, although only 42% showed strabismus at 6 months. Thirty percent of infants with strabismus at 6 months showed normal alignment at 9 months. Conclusions: Infants with high-risk prethreshold ROP show significant variability in the presence vs absence of strabismus in the first year of life; thus, conservative management is recommended. Application to Clinical Practice: Ophthalmologists managing strabismus in infants who have high-risk prethreshold ROP should be aware of the significant variability in ocular alignment during the first year of life.