Abstract:

Objective To investigate the distribution of the axial length and corneal curvature and its associated factors in 4-16 year old children. Design Cross-sectional study. Participants Two thousand eight hundred and twenty six 4-16 year old children in Changping Distric in Beijing. Methods Using a random cluster sampling method, the study included children from ten schools in Changping Distric in Beijing. The children underwent questionnaire, autorefraction and ocular biometry measurements. The questionnaire consisted of questions on the children’s basic information, family history and time spent outdoors and the activities performed outdoors, time spent indoor and the activities carried out indoors. We performed univariate and multivariate analyses of the associations between axial Length and corneal curvature and other parameters.  Main Outcome Measures Axial length, corneal curvature. Results The mean age of participants was 8.98±3.54 years. The mean axial length was 23.22±1.20 mm and the mean corneal curvature was 43.33±1.40 diopters (D). The axial length of males (23.45±1.15 mm) was significantly longer than that of females (23.00±1.21 mm) (P<0.001). The corneal curvature (D) of males (43.01±1.35 D) was significantly smaller than that of females (43.64±1.37 D) (P<0.001). In multivariate linear regression analysis, longer axial length was significantly associated with older age (P<0.001), male gender (P<0.001), smaller corneal curvature (P<0.001), deeper anterior chamber depth(P<0.001), smaller spherical equivalents(P<0.001). Steeper cornea was significantly associated with female (P<0.001), shorter axial length (P<0.001), deeper anterior chamber depth (P<0.001), smaller horizontal corneal diameter (P<0.001), smaller spherical equivalents (P<0.001), non-paternal myopia (P=0.029), less time spent watching TV (P<0.001). Conclusion Longer axial length was significantly associated with older age, male gender, smaller corneal curvature, deeper anterior chamber depth, smaller spherical equivalents. Steeper cornea was significantly associated with female, shorter axial length, deeper anterior chamber depth, smaller horizontal corneal diameter, smaller spherical equivalents, non paternal myopia, less time spent watching TV.  (Ophthalmol CHN, 2017, 26: 307-312)

Key words:  axial length, corneal curvature, children