Age-specific distribution of oculometric parameters and myopia in children aged 8-12y

AIM:To describe the distribution of ocular biometrics and to evaluate its associations with refractive error and to assess the contribution from ocular parameters to refractive error among Chinese myopic children.METHODS:This cross-sectional study evaluated subjects aged 8-12y.Keratometry,ocular biometry,and cycloplegic autorefraction were performed on each subject.Spherical equivalent refraction(SER)and ocular biometrics were assessed as a function of age and gender.The Pearson correlation analysis between SER and ocular biometrics was carried out.Multiple linear regression was performed to analyze the association between SER and ocular parameters.RESULTS:A total of 689 out of 735 participants(321 boys,48.1%)were analyzed,with a mean SER of-2.98±1.47 diopter(D).Axial length(AL),anterior chamber depth(ACD),corneal radius of curvature(CR),horizontal visible iris diameter(HVID),central corneal thickness(CCT)and lens power(LP)showed normal distribution.The AL,AL/CR ratio,ACD and CR increased from 8 to 12y of age,while SER and LP decreased,HVID and CCT remained stable.There was no difference in gender.SER decreased by 0.929 D for every 1 mm increase in AL and decreased by 1.144 D for every 0.1 increase in AL/CR ratio.The Pearson correlation coefficient between SER and AL was-0.538(P<0.01)and-0.747(P<0.01)between SER and AL/CR ratio.For the SER variance,AL explained 29.0%,AL/CR ratio explained 55.7%,while AL,CR,ACD and LP explained 99.3%after adjusting for age and gender.CONCLUSION:The AL,CR,ACD and LP are the most important determinants of myopic refractive error during myopia progression.