INITIAL CROSS-SECTIONAL RESULTS FROM THE ORINDA LONGITUDINAL-STUDY OFMYOPIA

Background. Although investigations of human refractive error developm ent and normal ocular growth have been conducted for the last 50 years , no previous study of refractive error and the ocular components has measured all the ocular components. Methods. The Orinda Longitudinal S tudy of Myopia was initiated to characterize the development of refrac tive error and normal eye growth in a sample of predominantly Caucasia n children ages 6 to 14 years. Results. Cross-sectional results from 5 30 children ages 5 to 12 years in the lst, 3rd, and 6th grades are pre sented. Conclusions. This sample's refractive error decreased toward e mmetropia with age from an average of +0.73 D at age 6 years to an ave rage of +0.50 D by age 12 years. Between the ages of 6 and 12 years, t he vitreous chamber elongated (by 0.52 mm) and the crystalline lens po wer decreased (by 1.35 D); surprisingly, the crystalline lens thinned by 0.14 mm during this same time period.