Intraocular pressure and associated factors in children: the Shandong children eye study.

PURPOSE We examined the distribution of intraocular pressure (IOP) and its associated factors in children. METHODS Using a random cluster sampling from kindergartens, primary schools, and junior and senior high schools from rural Guanxian County and the city of Weihai, the school-based cross-sectional Shandong Children Eye Study included children aged 4 to 18 years. All participants underwent an ocular examination, including ocular biometry, cycloplegic refractometry, and noncontact tonometry. RESULTS Mean IOP was 17.6 ± 2.7 mm Hg (range, 10-28 mm Hg). The IOP increased up to an age of 10 years and subsequently decreased with older age. In multivariate regression analysis, higher IOP was associated with female sex (P < 0.001; standardized correlation coefficient β, 0.06; regression coefficient β, 0.34; 95% confidence interval [CI], 0.18, 0.50), higher body mass index (P < 0.001; correlation coefficient β, 0.09; regression coefficient β, 0.07; 95% CI, 0.04,0.09), younger age (P < 0.001; correlation coefficient β, -0.15; regression coefficient β, -0.13; 95% CI, -0.17,-0.10), maternal myopia (P < 0.001; correlation coefficient β, 0.05; regression coefficient β, 0.34; 95% CI, 0.15,0.53), and more time spent indoors with reading/writing (P = 0.002; correlation coefficient β, 0.05; regression coefficient β, 0.07; 95% CI, 0.03,0.11), and with the ocular parameters of longer axial length (P < 0.001; correlation coefficient β, 0.14; regression coefficient β, 0.29; 95% CI, 0.21,0.37) and smaller corneal horizontal diameter (P < 0.001; correlation coefficient β, -0.06; regression coefficient β, -0.31; 95% CI, -0.46,-0.15). CONCLUSIONS In children aged 4 to 18 years, IOP showed an M-shaped association with age. Higher IOP was associated with the nonocular parameters of female sex (P < 0.001), higher body mass index (P < 0.001), younger age (P < 0.001), maternal myopia (P < 0.001), and more time spent indoors with reading/writing (P = 0.002), and with the ocular parameters of longer axial length (P < 0.001) and smaller corneal horizontal diameter (P < 0.001).