Preterm refraction and ocular biometry in children with and without retinopathy of prematurity in the first year of life

PURPOSE To determine ocular biometric and refractive profiles of premature children at risk of retinopathy of prematurity (ROP), comparing those who did and did not require laser treatment. METHODS In this prospective study, premature infants underwent biometry and refraction with their first ROP examination. Study parameters were assessed again at 3 months, 6 months, and 1 year. The main outcome measures were spherical equivalent, axial length, and keratometry. RESULTS A total of 122 infants (243 eyes) were included. At baseline, infants without ROP, those with ROP who never needed treatment, and those who later needed treatment had overall comparable axial length (P = 0.53) and myopia (P = 0.05); the highest severity group had higher corneal steepness and more myopia at baseline. At 1 year, children with laser-treated ROP had the shortest axial lengths, with the least decrease in keratometry, and the greatest increase in myopia (-2.0 D; P = 0.001). Anisometropia, if present initially, persisted through the 1-year examination. Mean refractive error was more myopic in zone 1 disease (P = 0.3) and in aggressive posterior ROP (P = 0.15). CONCLUSIONS Severe ROP is associated with disruption of emmetropization, and steeper corneas and more myopia at the first ROP examination, before any intervention. In our study cohort, these differences became more marked over the course of 1 year after laser therapy. The myopia in these cases was not axial. Laser therapy did not induce new anisometropia.