Abstract
Abstract: :
Purpose: To describe the development of refraction cross–sectionally and individually in 10–year–old prematurely–born children, to investigate if there is any relation between stage of ROP in the neonatal period and the course of refraction, and to identify risk factors for clinically significant refractive error at 10 years of age. Methods: Children from a previous population–based study on the incidence of ROP, with a birthweight of 1500 grams or less and born in the Stockholm area of Sweden during 1988 – 1990, were prospectively followed ophthalmologically up to 10 years. Cykloplegic refractions were performed at 6 months, 2.5 and 10 years. In the present study, 81% (198/248) of the original study group, with refractions at all occasions, were included. Cross–sectional and individual analyses were performed. Spherical equivalents were calculated. Myopia was defined as < 0 diopters (D), "clinically significant" myopia as <= –1D, and moderate or high myopia as +3D was regarded as significant. Results: All subgroups of ROP (no, mild, severe untreated, cryotreated ROP) had a similar course of refractive development over the years, although the cryotreated eyes had lower mean values of spherical equivalents at all the three retinoscopies. The distribution of refractive errors was similar in the groups with no ROP, mild and severe untreated ROP. In the cryotreated eyes, however, a different pattern was found with a broader distribution of the refractive errors and an increased prevalence of myopia. Cross–sectional and individual analyses of the refractive course reveal that refraction at 6 months is unpredictable, but that refraction at 2.5 years is more reliable for predicting clinically significant refractive errors at 10 years. Conclusion: Prematurely–born children have an increased risk of refractive errors, regardless of severity of ROP. It is therefore important to identify children who need glasses, to provide optimal visual development and to prevent amblyopia. The present study concludes that refraction at 6 months is unpredictable regarding future refractive errors. Examination around 2.5 years, however, seems to be a better tool for identification of children with refractive errors, which still remain at the age of 10 years.
Keywords: refractive error development