Changes in refraction and corneal curvature during growth and adult life. A cross-sectional study.

A cross-sectional analysis was performed regarding refractive value (spherical equivalent) and keratometry in a sample comprising 454 subjects aged 5-80 years. The refractive range was + 5.5 to -6.75D. According to the requirements of a parallel study of eye position and age, eyes with excessive ametropia had been excluded, but otherwise the sample was considered refractively unselected. Concerning refractive distribution, the present data supplement previous investigations of adults by the first author. Myopia increased from 6% in the age group 5-10 years to a peak level about 35% in adults aged 20-40, with a subsequent decrease towards old age, where hypermetropia showed a significantly increasing share. Concerning corneal curvature radius, male and female mean values (7.93 and 7.75 mm) showed no variation through the age span under study, however with a tendency of decreasing at old age (significantly in males only). The possible association with refractive change by age is discussed. Corneal astigmatism showed the established shift from predominantly with-rule in the very young to more against-rule and oblique astigmatism cases in older subjects.