Abstract
Purpose :
According to school health statistics from the Ministry of Education, Culture, Sports, Science and Technology of Japan, the number of children of school age with myopia is increasing. However the underlying causes behind the outbreak and progress of myopia are still unknown. Therefore we undertook a 5-year large-scale epidemiologic study of approximately 290,000 eyes of Japanese patients, who had been prescribed soft contact lenses (SCL), to correct ametropia. The purpose of this study was to evaluate the effect of gender, age, and myopic degree with on the progression of myopia.
Methods :
The subject of this study was the eyes of patients, in the 10 to 29 year age range, who were prescribed SCL at Okada Eye Clinic in Kanagawa, Japan, between 2002 and 2011. Subjects were tracked over a 5-year period (between 2007 to 2016). From a total of 1,211,608 eyes who were prescribed SCLs, the total number of eyes which were able to be tracked for the full 5 years was 290,775 (108,610 male; and 182,165 female).
Results :
First, analysis was conducted of the change in the degree of refraction over the 5 years by sex and age. The change in refractions towards myopia was highest at 10 years old (-2.136D male and -2.248D female) and lowest at 29 years old for both sexes (-0.179D male and -0.133D female). In ages under 14, this change was higher in females than in males. However, in ages 15 or over, it was higher in males.
Furthermore, the power of SCL prescribed on first visit to Okada Eye Clinic was checked and divided into 3 groups of myopia (high myopia (S < -6.00D); medium myopia （-6.00D ≤ S < -3.00D); low myopia (-3.00D ≤ S < -0.25D). Resulting analysis of the 3 myopia groups showed a change in degree of refraction over 5 years of: -0.299D in high myopia; -0.427D in medium myopia; and -0.525D in low myopia.
Conclusions :
Analysis was conducted of changes in the degree of refraction over 5 years in the 10 to 29 year age range by gender, age, and myopic degree. As a result, it can be determined that myopia progression gradually became slower with age; that myopia progressed faster in males than females at age 15 years and older; and that the weaker the myopia at baseline, the higher the change in refractions towards myopia.
This is a 2020 ARVO Annual Meeting abstract.