Abstract
Purpose :
It is a common belief in China that much myopia among children is “false” and should not be corrected with glasses lest they weaken the eyes. We used a longitudinal, population-based study to 1) investigate the prevalence of pseudomyopia and over-minused glasses prescriptions, and 2) test the hypothesis that wearing spectacles with over-minused power accelerates progression of myopia among Chinese children.
Methods :
2612 Grade 1 children (mean age 6.5±0.5years) and 1984 Grade 7 children (mean age 13.0±0.5) underwent cycloplegic refraction. At 12 months, the follow-up rates were 88.9% and 87.3% respectively. Myopia was defined as cycloplegic spherical equivalent (SE)≤−0.50 D, and pseudomyopia as SE≤−0.50 D before cycloplegia and >−0.50 D after cycloplegia, and over-minused power as the child's current worn SE subtracted from cycloplegic SE. Data from the better-seeing eye were analyzed. Repeated measures analysis followed by the Bonferroni post hoc test was used to compare each group.
Results :
The prevalence of myopia was 5.7% in Grade 1 and 62.8% in Grade 7, with the prevalence of pseudo-myopia 24.2% and 18.9% respectively. Among the 26 (1%) Grade 1 children who wore glasses, 16 (62%) were over-minused, while among 767 (39%) Grade 7 children with glasses, 137 (18%) were over-minused. In the univariate model, being over-minused among Grade 1 children was not associated with increase in myopic power over 12 months (p=0.79), whereas it was for Grade 7 children (0.151 D of additional myopic change for every diopter of over-minusing at baseline, p<0.001). In multivariate models, being over-minused among Grade 7 children was still statistically significantly associated with myopic progression (0.014 D for every diopter of over-minusing at baseline, p=0.001) though the magnitude was less clinically significant.
Conclusions :
In China, the prevalence of both pseudomyopia and wear of over-minused spectacles is higher in younger compared to older children, suggesting that cycloplegia is not sufficiently widely-used for pediatric refraction. However, over-minused spectacle wear has little clinical effect on myopia progression, suggesting that concerns over pseudo-myopia in China may not be entirely warranted. Data on a population-based Australian cohort collected with similar methods will also be presented.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.