title: The development of myopia in Hong Kong children between the ages of 7 and 12 years: a five-year longitudinal study.
abstract: The purpose of this work was to characterize the development of refractive error in Hong Kong children between the ages of 7 and 12 years. A non self-selected sample of 7-year old children was recruited and followed for 5 years, non-cycloplegic refractions being carried out annually. A life-table was used to determine myopia incidence and prevalence. The mean annual change in the spherical equivalent refraction (SER) was -0.32 D; 75 out of 83 subjects followed for 5 years became less hyperopic or more myopic, the maximum progression occurring between 9 and 11 years of age. The mean change in SER over the 5 years in children who were myopic at age 12 years was significantly greater than that in children who remained non-myopic. The incidence of myopia at age 7-8 years was 9% and at age 11-12 years was 18-20%. At age 7 years the prevalence of progressive myopia was 1.6% and 2.5% of subjects had anisometropia. Any treatment to prevent myopia should start by the age of 6 years and treatment to retard development should commence before age 9 years.
authors.affiliation: Department of Optometry and Radiography, Hong Kong Polytechnic University, Hong Kong.
authors.forename: M H
authors.initials: MH
authors.lastname: Edwards
mesh_terms: D000375:Aging / Q000502:physiology; D015858:Anisometropia / Q000453:epidemiology; D002648:Child; D018450:Disease Progression; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D009216:Myopia / Q000453:epidemiology* / Q000628:therapy; D015995:Prevalence; D012029:Refraction, Ocular