Ocular Component Growth Curves among Singaporean Children with Different Refractive Error Status

Abstract

PURPOSE: To describe and compare ocular component growth curves among different refractive error groups in Singaporean children. METHODS: Data collected yearly in 1775 Asian children aged 6 to 10 years with at least three visits were analyzed. Cycloplegic refractive error and biometry variables were measured by autorefractor and A-scan ultrasound machine. Growth curves were compared between five groups: persistent hyperopia of spherical equivalent (SE) > +1.00 D, emmetropizing hyperopia of SE > +1.00 D on the first visit and between -0.50 D and +1.00 D subsequently, persistent emmetropia of SE between -0.50 D and +1.00 D, incident myopia of SE <or= -0.50 D at subsequent visits, and persistent myopia of SE <or= -0.50 D. RESULTS: The axial length and vitreous chamber elongated faster in the children younger than 10 years, but elongation slowed with age. Growth patterns of axial length and vitreous chamber in the children with newly developed or persistent myopia (P < 0.01) showed faster elongation than in the emmetropic children. The anterior chamber deepened until approximately 9 or 10 years of age but became shallower as the myopic and emmetropic children grew older. Conversely, the lens thinned at younger ages and thickened at older ages for all except the persistently hyperopic children. CONCLUSIONS: In young Asian children, the axial length and vitreous chamber depth increased, but the elongation slowed with age. There was a U-shaped growth curve for lens thickness and an inverted U-shaped curve for anterior chamber depth. The findings of early lens thinning followed by thickening suggest a two-phase growth of the lens.