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.

The development of myopia in Hong Kong children

“…The prevalence of myopia and the average progression is in good accordance with previous HK studies (Lam et al 1999;Edwards 1999). The Hong Kong children develop myopia earlier than in most other parts of the world.…”

“…T he high prevalence, early onset and fast progression of myopia among Hong Kong children is well documented (Lam & Goh 1991;Lam et al 1999;Edwards 1999). The role of nearwork in the etiology of myopia has been reviewed in a recent publication (Rosenfield & Gilmartin 1998), but nearwork as a predominant etiological factor cannot alone explain the present pattern of myopia distribution.…”

Changes in refraction in anisomyopic patients

“…The less myopic eye of anisometropic patients seems to behave the same way as in a normal myopic population, tending to shift towards increasing myopia during the first 30 years of life (p < 0.001). 7,14,15 As reported by other authors, the eye with a high degree of myopia tends to have a stable refraction (p = 0.804), unless there is a family history of progressive myopia. 16,17 Similarly, in a strabismic population, Lepard 13 observed that the fixating eye tended to become more myopic, while no appreciable refractive changes were noted in the amblyopic eye.…”

A Survey of the Prevalence of Refractive Errors among Children in Lower Primary Schools in Darnah City, Libya

“…Although worldwide geographic and ethnic differences in the prevalence of childhood refractive error are well recognized [31][32][33][34][35][36][37], meaningful comparisons between reports in the literature are problematic. The difficulty arises because of different or inadequately described survey and examination methods (such as whether cycloplegia was used), unclear or no uniform definitions for hyperopia and myopia, and differences underlying the age and gender mix of the populations studied.…”