Trends in the change of clinical refractive error in myopes.

Longitudinal records of 559 myopes were obtained from five optometric practices. A linear regression model was used to describe various parameters of myopia progression, including onset age, rates, and cessation age of childhood progression. Typical rates of childhood myopia increases are around 0.4 D/yr, although there is considerable individual variability. An earlier onset is correlated with the development of a higher final amount of myopia. The earlier cessation age of childhood myopia progression in females than in males is hypothesized to be related to growth factors.