Emetropização na Infância

Abstract

Introduction: The growth of the eye is characterized, not only, by the increase in size of its constituents, but it is also influenced by the individual's genetic heritage as well as his environment and visual exposure in an active emmetropization process, that makes the refractive errors present at birth disappear. Methods: We carried out a bibliographic research at MedLine. Non-experimental longitudinal studies were selected in healthy populations of children up to 10 years of age, whose refractive errors were measured objectively and under cycloplegia. Results: Hyperopia is the most common refractive error in early childhood. Up to 18 months of age, there is a marked variation in the spherical equivalent. The incidente of myopia is reported between 27.3% to 36.2% from 7 to 11 years of age. The variation of the spherical equivalent tends toward myopization at different speeds depending on the age of the child and the presence of refractive errors. Astigmatism is also common in early childhood and decreases in prevalence and value over age. Its late incidence is low with 10.9% of children developing astigmatism from 8 to 11 years of age. Discussion: The presence of myopia in early infancy is a predictor of higher degrees of myopia later in life and hyperopia seems to be protective. The role of astigmatism in the process of emmetropization is not yet clear. Conclusion: The variability between the different studies limits the extrapolation of definitive conclusions about the process of emmetropization between different populations.