PURPOSE. Although it is expected that juvenile onset myopia progresses with increasing age, less is known about changes in emmetropic or hyperopic refractive error during the school years. Parents often report that an optometrist did not prescribe for their child’s hyperopia with the expectation that the child will "grow out of it." The purpose of this report is to describe the growth patterns of the ocular components in school-aged children.
METHOD. Children enrolled in the Orinda Longitudinal Study of Myopia constituted this sample. Myopia was defined as a cycloplegic autorefraction result of at least-0.75 D in either meridian at any visit, emmetropia as between +1.00 D and-0.75 D in both the vertical and horizontal meridians at all visits, and hyperopia as at least +2.00 D in either meridian at any visit. This definition resulted in a sample of 512 children between the ages of 6 and 14 years with at least two years of follow-up (across three annual visits) between 1989 and 1997 (140 myopes, 339 emmetropes, and 33 hyperopes). The measurements made included refractive error (cycloplegic autorefraction), crystalline lens power, and axial length.
RESULTS. On average, the myopes’ refractive error changed by-0.39 D per year, the emmetropes’ refractive error changed by +0.02 D per year, and the hyperopes’ refractive error changed by +0.10 D per year (p<0.001 with the myopes significantly different from both the emmetropes and the hyperopes). Gullstrand crystalline lens power decreased by 0.18 D, 0.29 D, and 0.60 D respectively (p=0.002, with the hyperopes significantly different from the other two groups). Axial length increased by an average of 0.24 D, 0.11 D, and 0.12 D respectively (p<0.001 with the myopes significantly different from the other two groups).
CONCLUSIONS. The annual changes in the axial length and crystalline lens power in school-aged children result in progression of myopia and stability of emmetropia and hyperopia. Clinicians should consider correcting hyperopia in children early and aggressively, as it is unlikely to resolve spontaneously.