A 2-year longitudinal study of myopia progression and optical component changes among Hong Kong schoolchildren

Optom Vis Sci. 1999 Jun;76(6):370-80. doi: 10.1097/00006324-199906000-00016.


This study investigated refractive error and optical component changes in a group of 142 Hong Kong schoolchildren from age 6 to 17 years over a 2-year period between 1991 and 1993. Subjects were refracted subjectively and corneal curvatures and ocular dimensions were measured. At the end of the 2-year study, the mean spherical equivalent refraction (SER) was -1.86 D (SD 1.99 D) and 62% of the schoolchildren were myopic. The annual incidence of myopia was 11.8%. Children aged 10 years and under had a greater change in SER toward myopia than older children. The annual rate of myopia progression for the myopic children was -0.46 D (SD 0.40 D) and the rate of progression was greatest between age 6 and 10 years old. Vitreous depth/axial length elongation was the main component contributing to the progression of myopia. Hong Kong schoolchildren develop myopia as early as 6 years old and myopia progresses at a greater rate compared with children of European extraction.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Age Factors
  • Child
  • Cornea / physiopathology
  • Disease Progression
  • Eye / physiopathology*
  • Female
  • Follow-Up Studies
  • Hong Kong / epidemiology
  • Humans
  • Incidence
  • Male
  • Myopia / epidemiology
  • Myopia / pathology
  • Myopia / physiopathology*
  • Prevalence
  • Refraction, Ocular*
  • Retrospective Studies
  • Sex Factors
  • Vitreous Body / physiopathology