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Background: To assess the corneal diameter and its associations in children., Design: Cross-sectional school-based study., Participants: Six thousand twenty-six children aged 4-18 years were included in the Shandong Children Eye Study., Methods: Horizontal corneal diameter was measured by laser interferometry-based ocular biometry., Main Outcome Measures: Horizontal corneal diameter., Results: Corneal diameter measurements were available for 5970 (99.1%) children. In multivariate analysis, larger horizontal corneal diameter (mean: 12.02 ± 0.38 mm; range: 10.1-15.0 mm) was associated with longer corneal curvature radius longer axial length, male gender, younger maternal age, rural region of habitation and lower intraocular pressure measurements. Higher prevalence of abnormally large corneas (macrocorneas; horizontal diameter ≥ 12.76 mm; mean value +2  ×  standard deviations; mean: 2.6%; 95% CI: 2.2, 3.0) was associated with longer corneal curvature radius, longer axial length, younger maternal age and male gender. Higher prevalence of abnormally small corneas (horizontal diameter ≤ 11.24mm; mean value -2 × standard deviations; mean: 2.4%; 95% CI: 2.0, 2.8) was correlated with shorter corneal curvature radius, shorter axial length and urban region of habitation. Neither abnormally large nor small corneas were correlated with time spent indoors/outdoors., Conclusions: In 4 to 18-year-old children, larger corneal diameter was associated most strongly with flatter corneal curvature, followed by longer axial length and male gender. Corneal diameter was independent of age beyond an age of 4 years. Abnormally large and abnormally small corneas may be defined as being ≥12.76 and ≤11.24 mm in diameter, respectively. Corneal diameter was not correlated with time spent indoors/outdoors., (© 2016 Royal Australian and New Zealand College of Ophthalmologists.)

Purpose: To describe prevalence and associations of anisometropia in children., Methods: The cross-sectional school-based study included children aged 4 to 18 years., Results: The study included 6025 (94.7%) of 6364 eligible children. Mean refractive anisometropia was 0.37 ± 0.57 diopters (median: 0.25 diopters; range: 0-7.88 diopters; prevalence [≥1 diopter]: 7.0% ± 0.3%). In multivariate analysis (regression coefficient r: 0.66), higher refractive anisometropia was associated with older age (P < 0.001; β: 0.07; B: 0.01; 95% CI: 0.01-0.02), higher maternal education level (P < 0.001; β: 0.04; B: 0.02; 95% CI: 0.01-0.03), more total time spent indoors reading or writing (P = 0.001; β: 0.04; B: 0.01; 95% CI: 0.01-0.02), larger intereye difference in axial length (P < 0.001; β: 0.57; B: 1.20; 95% CI: 1.15-1.24), shorter mean axial length of both eyes (P = 0.03; β: -0.03; B: -0.02; 95% CI: -0.03 to -0.001), larger intereye difference in best corrected visual acuity (BCVA) (P < 0.001; β: 0.14; B: 1.83; 95% CI: 1.54-2.12), and lower stereoacuity (P < 0.001; β: 0.08; B: 0.31; 95% CI: 0.22-0.39). Refractive anisometropia showed a U-shaped correlation with refractive error. Higher anisomyopia was associated (r: 0.57) with older age (P = 0.001; β: 0.05; B: 0.006; 95% CI: 0.002-0.009), higher level of paternal education (P = 0.001; β: 0.01; B: 0.01; 95% CI: 0.01-0.02), more total time spent indoors reading or writing (P = 0.01; β: 0.03; B: 0.01; 95% CI: 0.00-0.01), larger intereye difference in axial length (P < 0.001; β: 0.22; B: 0.26; 95% CI: 0.23-0.29), greater myopic refractive error (P < 0.001; β: -0.46; B: -0.07; 95% CI: -0.08 to -0.07), and lower corneal astigmatism (P < 0.001; β: -0.10; B: -0.06; 95% CI: -0.08 to -0.05). In the same multivariate model, hyperopic anisometropia was not significantly associated with time spent indoors with reading (P = 0.18). Cylindrical anisometropia (mean: 0.30 ± 0.32 diopters; prevalence [≥1 diopter]: 3.7% ± 0.2%) increased with higher refractive anisometropia (P < 0.001; β: 0.16; B: 0.09; 95% CI: 0.08-0.11), greater myopic refractive error (P < 0.001; β: -0.06; B: -0.01; 95% CI: -0.01 to -0.01), higher corneal astigmatism (P < 0.001; β: -0.22; B: -0.15; 95% CI: -0.17 to -0.13), and lower mean BCVA (P < 0.001; β: 0.11; B: 0.90; 95% CI: 0.68-1.17)., Conclusions: In 4- to 18-year-old children, refractive anisometropia and anisomyopia increased with systemic parameters such as age, parental education level, and lifestyle of the children, for example, more time spent indoors reading or writing. In contrast, hyperopic anisometropia and cylindrical anisometropia were not related with lifestyle parameters.

Purpose: To investigate ocular axial length (AL) in Chinese children., Methods: The Shandong Children Eye Study included 6,364 children aged 4-18 years., Results: Longer AL (mean 23.45 ± 1.20 mm, range 18.80-28.59 mm) was associated (multivariate analysis; correlation coefficient r2: 0.61) with older age (p < 0.001, standardized correlation coefficient β = 0.35, unstandardized regression coefficient B = 0.13, 95% confidence interval [CI] 0.12, 0.15), male gender (p < 0.001, β = -0.24, B = -0.10, 95% CI -0.29, -0.19), urban region (p < 0.001, β = 0.10, B = 0.25, 95% CI 0.20, 0.31), body height (p < 0.001, β = 0.22, B = 0.02, 95% CI 0.01, 0.02), maternal education (p < 0.001, β = 0.07, B = 0.07, 95% CI 0.05, 0.10), paternal myopia (p < 0.001, β = 0.09, B = 0.26, 95% CI 0.20, 0.33), maternal myopia (p < 0.001, β = 0.08, B = 0.23, 95% CI 0.17, 0.30), more time spent indoors reading/writing (p < 0.001, β = 0.05, B = 0.03, 95% CI 0.02, 0.04), less time spent outdoors (p = 0.005, β = -0.03, B = -0.01, 95% CI -0.02, -0.003), longer corneal curvature radius (p < 0.001, β = 0.36, B = 1.63, 95% CI 1.53, 1.74) and higher intraocular pressure (p = 0.008, β = 0.03, B = 0.01, 95% CI 0.004, 0.02). High axial myopia (AL ≥26.0 mm) present in 202 children (3.4 ± 0.2%, 95% CI 2.92, 3.84) was associated with less time spent outdoors (p = 0.002, odds ratio 0.92, 95% CI 0.87, 0.97) in multivariate analysis., Conclusions: In children in the less developed Eastern Chinese province of Shandong, the prevalence of high axial myopia was >10% among 16-year-olds. A modifiable factor associated with higher prevalence of high axial myopia was less time spent outdoors., (© 2016 S. Karger AG, Basel.)

Purpose: To examine the thickness of the macular choroid and its associations in school children aged 6 to 18 years., Methods: The school-based cross-sectional Shandong Children Eye Study included 6026 (94.7%) of 6364 eligible children fulfilling the inclusion criterion of an age from 4 to 18 years. Spectral-domain optical coherence tomography (SD-OCT) was performed for a subgroup of 972 school children aged 6+ years. All participants underwent ocular examinations, including measurement of visual acuity, cycloplegic refractometry, biometry, and SD-OCT (enhanced depth imaging mode) for measurement of choroidal thickness., Results: The study included 972 children (501 girls) with a mean age of 11.3 ± 3.3 years (range, 6-18 years) and mean axial length of 24.10 ± 1.56 mm (range, 16.57-28.82 mm). Mean choroidal thickness was thicker (P < 0.001) at 500 μm temporal to the foveola (290 ± 67 μm) than in the subfoveal region (283 ± 67 μm; range, 113-507 μm) and the region 500 μm superior to the fovea (283 ± 66 μm), where it was thicker (P < 0.001) than at 500 μm inferior of the foveola (281 ± 66 μm), and it was thinnest (P < 0.001) at 500 μm nasal of the foveola (268 ± 67 μm). In multivariate analysis, thicker SFCT was (overall correlation coefficient r: 0.51) associated with shorter axial length (P < 0.001; standardized correlation coefficient β: -0.48; B: -23.7; 95% confidence interval [CI]: -27.2 to -20.3), male sex (P = 0.006; β: -0.08; B: -10.7; 95% CI: -18.3 to -3.11), and younger age (P = 0.04; β: -0.07; B: -1.46; 95% CI: -2.85 to -0.07)., Conclusions: As in adults, thicker SFCT in children and teenagers was markedly associated with shorter axial length, and to a lesser degree with male sex and older age. As in adults, increasing axial myopia in teenagers is associated with choroidal thinning and development of a leptochoroid.