Objective. The authors report on the incidence of myopia and strabismus at 12 and 24 months postterm in a cohort of 190 premature infants with birth weights of less than 1251 g born in 1986 and 1987.
Methods. The neonatal and follow-up eye charts of a cohort of 190 premature infants were retrospectively reviewed. All 138 children who survived the neonatal period had at least one eye examination between day 28 and 42 of life that documented the presence and staging of retinopathy of prematurity (ROP) according to the International Classification of ROP. No infants received cryotherapy. Eye examinations conducted at 12 and 24 months postterm included assessment of vision, fundus, ocular motility, anterior segment abnormality, and refractive error. Eyes were refracted using cycloplegic retinoscopy. Strabismus was detected using the Hirschberg and cover tests. Eye reports were available for 80% (n = 110) at 12 months and 36% (n = 50) at 24 months.
Results. Fifty-three percent of the cohort exhibited ROP in the neonatal period; 12% of these progressed to stage 3 or 4 ROP. Myopia was observed in 16% (18/110) of the cohort at 12 months of age; 4.5% (5/110) measured more than 4.0 diopters of myopia. Children with birth weights of less than 751 g were 3.2 times more likely than those with birth weights between 751 and 1000 g and 10 times more likely than those with birth weights between 1001 and 1250 g to develop myopia in the first year of life. The likelihood of myopia at 12 months doubled with each increment in ROP stage. Of the 50 children reexamined at 24 months postterm, more than 80% demonstrated deteriorating vision. The incidence of myopia increased to 38% (19/50) overall, with 24% (12/50) of the cohort showing severe myopia. Astigmatism and anisometropia were highly correlated with severe myopia. Strabismus was seen with increasing frequency through the second year of life. All children with grade III or IV intraventricular hemorrhage in the neonatal period developed esotropia.
Conclusion. This study emphasizes the significant roles of low birth weight, ROP, and intraventricular hemorrhage in the development of myopia and strabismus. Follow-up to 2 years of life is recommended given the demonstrated deterioration our cohort.
- Received January 19, 1993.
- Accepted May 27, 1993.
- Copyright © 1993 by the American Academy of Pediatrics