Development of spherical equivalent refraction in prematurely born children during the first 10 years of life: a population-based study.

OBJECTIVE

To evaluate the development of refraction, expressed as spherical equivalents, in prematurely born children during the first 10 years of life.

METHODS

Retinoscopy in cycloplegia was performed at 6 months, 2.5 years, and 10 years of age in 198 prematurely born children from a previous population-based study on the incidence of retinopathy of prematurity. Spherical equivalents were calculated. Myopia was defined as a spherical equivalent of less than 0 diopters (D), clinically significant myopia at 10 years of age as -1 D or less, and moderate or high myopia as less than -3D. Hypermetropia greater than +3 D was regarded as significant.

RESULTS

There were no significant differences during the refractive development between the various subgroups of retinopathy of prematurity. Cryotreated eyes had a wider distribution of refractive errors. A multiple regression analysis revealed that the spherical equivalents at 2.5 years of age predicted clinically significant myopia (</=-1 D) at 10 years of age.

CONCLUSIONS

Retinoscopies at 6 months, 2.5 years, and 10 years of age show a similar course of spherical equivalent refractive development regardless of the stage of retinopathy of prematurity. Refraction at 6 months of age is an unreliable predictor, but the refraction at 2.5 years of age seems to be a better tool for identifying refractive errors that will remain at 10 years of age.