The effects of mild-to-severe retinopathy of prematurity on the development of refractive errors and strabismus

Purpose: To investigate the effects of mild-to-severe retinopathy of prematurity (ROP) on refractive state and the incidence of strabismus. Materials and methods: Infants born <= 32 weeks of gestation were prospectively evaluated. Inclusion criteria were a follow-up of at least 6 months and at least stage 1 ROP. Group 1 included stage 1 ROP cases. Cases with stage 2 or 3 ROP without indication for treatment formed the second group. Group 3 included cases who received treatment for ROP. Logistic regression, adjusted for birth weight and gestational age, and multiple comparison tests were used to compare outcomes among groups. Results: The mean follow-up time was 20.9 +/- 6.6 months. In the first (n = 21), second (n = 22), and third groups (n = 23), the right spherical equivalents (SE) were 1.17 +/- 1.33, -0.18 +/- 3.09, and -1.08 +/- 4.05 diopters, and the left SEs were 1.23 +/- 1.34, -0.09 +/- 3.24, and -1.46 +/- 4.02 diopters, respectively (p = 0.026 for right SE and 0.008 for left SE). The incidences of anisometropia were 3/21, 4/22, and 11/23 in the first, second, and third groups, respectively (adjusted odds ratios [aOR] for group 3 vs 1 = 5.39, aOR for group 3 vs 2 = 4.06). Strabismus developed in 7/21, 6/22, and 10/23 in groups one, two, and three, respectively (aOR for group 3 vs 1 = 2.06, aOR for group 3 vs 2 = 2.27). Eighteen of these were esotropias. Conclusions: Refractive errors and strabismus were associated with mild-to-severe ROP. Esotropia was the most frequent type of strabismus.