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Background To assess the corneal diameter and its associations in children. Design Cross-sectional school-based study. Participants The Shandong Children Eye Study included 6026 children aged 4-18 years. 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;median:10.0 mm;range:10.1-15.0 mm) was associated (regression coefficient r:0.41) with longer corneal curvature radius (P

Objectives To investigate behaviour and expression of transforming growth factor-β (TGF-β) and matrix metalloproteinases (MMP-9) in murine photoreceptor-derived cells (661W) after incubation with zinc oxide (ZnO) nanoparticles. Materials and methods We explored effects of ZnO nanoparticles on 661W cells using a real-time cell electronic sensing system, flow cytometry, multiple function microplate reading, real-time quantitative PCR detection system and enzyme-linked immunosorbent assay respectively. Results Our results indicate that ZnO nanoparticles induced overload of calcium and reactive oxygen species within cells, causing formation of apoptotic bodies, disruption of cell cycle distribution, and reduction in expression of TGF-β and MMP-9, to suppress cell proliferation and migration. Our findings show that disruption of intracellular calcium homoeostasis and overproduction of reactive oxygen species were closely associated with reduction of TGF-β and MMP-9 in 661W cells under ZnO nanoparticle treatment. Conclusions Results of our study indicate that ZnO nanoparticles suppressed cell proliferation and migration, and reduced production of TGF-β and MMP-9 at both gene and protein levels. Our findings contribute to the understanding of the molecular mechanisms that reduced TGF-β and MMP-9 levels inhibit cell proliferation and migration under ZnO nanoparticle influence.

PURPOSE To present and evaluate modified scleral tunnel in prevention of tube exposure following Ahmed valve implantation in refractory glaucoma. METHODS In the Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine, a retrospective study was conducted in 36 eyes of 34 patients who were diagnosed with refractory glaucoma and underwent Ahmed glaucoma valve implantation. In the surgery, the modified scleral tunnel was done to prevent tube exposure. RESULTS At the end of follow-up (mean 21.68±9.25 mo), there was no conjunctival tube exposure in all 36 eyes. The mean intraocular pressure was 18.3±6.79 mmHg, and 8 eyes needed 1 to 3 types of drugs to decrease intraocular pressure. CONCLUSIONS The modified scleral tunnel technique in Ahmed glaucoma valve implantation is able to prevent conjunctival tube exposure in the patients with refractory glaucoma.

Purpose To analyze morphologic features of segmental parapapillary diffuse choroidal atrophy (PDCA) in children. Methods The study group included children (age ≤15 years) with high myopia who attended the Tokyo High Myopia Clinic. Control groups comprised participants of the population-based Gobi Desert Children Eye Study (GobiDCES). Fundus photographs were examined for presence of PDCA and choroidal thickness (CT) was measured by optical coherence tomography. Results The study group included 41 eyes of 21 children with PDCA (mean age: 9.4 ± 3.7 years; mean refractive error: -11.5 ± 3.1 diopters) and the GobiDCES included 1463 children (age: 11.8 ± 3.5 years). In the study group, all eyes showed an extreme and abrupt thinning of the temporal parapapillary choroid. At 2500 μm nasal to the foveola, CT was

Similar to memory formation, memory extinction is also a new learning process that requires synaptic plasticity. Actin rearrangement is fundamental for synaptic plasticity, however, whether actin rearrangement in the infralimbic cortex (IL) plays a role in memory extinction, as well as the mechanisms underlying it, remains unclear. Here, using a conditioned taste aversion (CTA) paradigm, we demonstrated increased synaptic density and actin rearrangement in the IL during the extinction of CTA. Targeted infusion of an actin rearrangement inhibitor, cytochalasin D, into the IL impaired memory extinction and de novo synapse formation. Notably, we also found increased myosin II phosphorylation in the IL during the extinction of CTA. Microinfusion of a specific inhibitor of the myosin II ATPase, blebbistatin (Blebb), into the IL impaired memory extinction as well as the related actin rearrangement and changes in synaptic density. Moreover, the extinction deficit and the reduction of synaptic density induced by Blebb could be rescued by the actin polymerization stabilizer jasplakinolide (Jasp), suggesting that myosin II acts via actin filament polymerization to stabilize synaptic plasticity during the extinction of CTA. Taken together, we conclude that myosin II may regulate the plasticity of actin-related synaptic structure during memory extinction. Our studies provide a molecular mechanism for understanding the plasticity of actin rearrangement-associated synaptic structure during memory extinction.

Posterior capsular opacification is the most frequent complication after cataract surgery, which is induced by the proliferation, differentiation and migration of lens epithelial cells. Inhibiting the proliferation of human lens epithelial cells could reduce the occurrence of posterior capsular opacification. To explore the possible potential of ZnO nanoparticles in treating posterior capsular opacification, we investigated the effect of ZnO nanoparticles on the human lens epithelial cell proliferation in the presence and absence of ultraviolet B (UVB) irradiation via 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. The results indicate that ZnO nanoparticles could apparently inhibit the proliferation of human lens epithelial cells in a dose-dependent manner, and UVB irradiation can further enhance this inhibitory role for the human lens epithelial cell proliferation, indicating the great potential of ZnO nanoparticles in treating posterior capsular opacification in clinical application.

To assess whether anterior corneal curvature radius (CCR) is associated with the increased prevalence of myopia in Asia.The investigation included the adult populations of the Central India Eye and Medical Study (CIEMS; 4711 adults) and Beijing Eye Study (BES; 3468 adults) and the children and teenager populations of the Shandong Children Eye Study (6026 children; age: 9.7 ± 3.3 years; range: 4-18 years) and Beijing Pediatric Eye Study (681 children; age: 7.7 ± 1.6 years; range: 5-13 years).In both adult study populations, CCR was not significantly (BES: P = 0.60; CIEMS: P = 0.14) associated with the level of education. In highly myopic subgroups, longer CCR was associated with a lower educational level [CIEMS: P = 0.04; standardized regression coefficient β = -0.23; nonstandardized regression coefficient B: -0.06; 95% confidence interval (CI), -0.11 to 0.01] or showed a tendency toward a lower educational level (BES: P = 0.09; β = -0.25; B: -0.06; 95% CI, -0.12 to 0.01). In the young study populations, longer CCR was significantly associated with parameters indicating a lower educational level, such as lower educational level of father (P = 0.001; β: -0.04; B: -0.01; 95% CI, -0.02 to -0.01) and mother (P = 0.0.02; β: -0.14; B: -0.05; 95% CI, -0.09 to -0.01) and more time spent outdoors (P = 0.001; β: 0.15; B: 0.05; 95% CI, 0.02 to 0.07) and less time spent indoors (P0.001; β: -0.15; B: -0.04; 95% CI, -0.06 to -0.02). In all study populations, longer CCR was significantly correlated (multivariate analysis) with longer axial length and lower prevalence of high myopia.Adult study populations and schoolchildren populations did not differ in the associations of longer CCR with parameters indicating a lower educational level, longer axial length, and lower prevalence of high myopia. CCR was not useful for the differentiation between high myopia in schoolchildren and high pathological myopia in adults.

Objectives As a parenchymal cell, the photoreceptor is more susceptible to alterations in outer micro-environmental conditions than other cells. In the present study, we aimed to investigate inhibitory effects of zinc oxide (ZnO) nanoparticles on expression of manganese superoxide dismutase (MnSOD) in murine photoreceptor-derived cells. Materials and methods We investigated effects of ZnO nanoparticles on murine photoreceptor cell viability and on expression and activity of MnSOD using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, immunofluorescence analysis, flow cytometry, quantitative real-time PCR and enzyme-linked immunosorbent assay (ELISA). Results ZnO nanoparticles were found to have higher cytotoxic effects in concentration- and time-dependent manners, to elevate intracellular levels of hydrogen peroxide and hydroxyl radicals, and thus to induce overproduction of reactive oxygen species (ROS) and collapse of mitochondrial membrane potential, leading to cell damage. Moreover, ZnO nanoparticles also significantly reduced expression of MnSOD at both the mRNA and protein levels, reduced its activity, and further aggravated oxidative stress-mediated cell damage. Conclusion Overall, ZnO nanoparticle-induced cytotoxicity was associated with elevated levels of oxidative stress due to overproduction of ROS and reduced expression and activity of MnSOD.

Titanium dioxide (TiO2) nanoparticles have been widely used in many fields, including biomedicine, cosmetics and environmental engineering. Recently, it was reported that TiO2 nanoparticles could exert genotoxicity on organisms via the generation of reactive oxygen species (ROS). In the present study, we investigated the effect of TiO2 nanoparticles on RGC-5 cells with or without ultraviolet (UV) B irradiation through MTT assay and determination of hydroxyl radical production. The results demonstrated that TiO2 nanoparticles could efficiently inhibit the growth of RGC-5 cells in the presence of UVB irradiation, whereas there was little impact on target cells in the absence of UV irradiation; UV irradiation could apparently increase the level of hydroxyl radicals in RGC-5 cells and further efficiently inhibit the growth of RGC-5 cells, suggesting that UV irradiation plays an important role in growth inhibition in RGC-5 cells exposed to TiO2 nanoparticles.

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.

To investigate the prevalence and risk factors for pterygium in rural older adults in Shandong Province, eastern China, a population-based, cross-sectional study was performed from April to July 2008. By means of cluster random sampling methods, a total of 19,583 people aged 50 years or above were randomly selected from four rural counties. Out of 19,583 people, 1,767 residents were excluded mainly because they were migrant workers when this study was performed. Finally, 17,816 (90.98%) people were included as eligible subjects. They received a comprehensive eye examination and a structured questionnaire voluntarily. Patients with pterygium were defined as having pterygium at the time of survey or pterygium surgery had been performed. 1,876 people were diagnosed as pterygium, either unilateral (1,083) or bilateral (793), which is equivalent to a prevalence of 10.53% (95% CI, 10.08–10.98). The multivariate logistic regression analysis showed that pterygium was independently associated with older age, areas, outdoor time, educational level, and use of hat and/or sunglasses. The prevalence of pterygium increased with age and hours spent under sunshine per day. Meanwhile, the higher the educational level and the more use of hat and/or sunglasses, the lower the pterygium prevalence.

PURPOSE: To examine the prevalence of refractive errors and prevalence and causes of vision loss among preschool and school children in East China. METHODS: Using a random cluster sampling in a cross-sectional school-based study design, children with an age of 4-18 years were selected from kindergartens, primary schools, and junior and senior high schools in the rural Guanxian County and the city of Weihai. All children underwent a complete ocular examination including measurement of uncorrected (UCVA) and best corrected visual acuity (BCVA) and auto-refractometry under cycloplegia. Myopia was defined as refractive error of ≤-0.5 diopters (D), high myopia as ≤ -6.0D, and amblyopia as BCVA ≤ 20/32 without any obvious reason for vision reduction and with strabismus or refractive errors as potential reasons. RESULTS: Out of 6364 eligible children, 6026 (94.7%) children participated. Prevalence of myopia (overall: 36.9 ± 0.6%;95% confidence interval (CI):36.0,38.0) increased (P

Background The prevalence of myopia has markedly increased within the past three decades, in particular in China. Because of myopic retinopathy and myopia-associated glaucoma, myopia has become one of the leading blinding disorders. Methods Conducting population-based studies and school-based investigations, we assessed prevalence and incidence of myopia and associated factors in children, university students, and adults in urban and rural regions of different Chinese provinces. We performed histomorphometric studies on human eyes, and examined whether the intraocular application of an antibody to amphiregulin was associated with a reduction of experimentally induced myopic axial elongation of eyes in guinea pigs. This study was approved by the ethics committee of the Shandong University of Traditional Chinese Medicine. Findings In nine population-based studies with up to 560 000 child and adult participants, the prevalence of myopia was about 80% in 18-year-old school children and 17% in adults aged 40 years and older. These figures were significantly higher in urban regions than in rural regions (OR 1·63, 95% CI 1·51–1·75, p 0·40) of axial length, as was Bruch's membrane thickness. Intraocular application of amphiregulin antibody reduced axial elongation in guinea pigs in a dosage-dependent manner (p=0·002; regression coefficient −0·58, 95% CI of difference 0·20 to 0·63). Interpretation These findings suggest that the increase in prevalence of myopia in the young Chinese generation is associated with lifestyle factors. The histological findings indicated that myopic axial elongation was associated with formation of Bruch's membrane in the midperiphery. Since the retinal pigment epithelium has receptors for amphiregulin, a member of the epithelial growth factor family, this hypothesis fits with the finding that amphiregulin antibody was associated with a dosage-dependent reduction in axial elongation. Further studies are warranted on the medical reduction of axial myopisation by amphiregulin antibody. Funding None.

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.

Background Recently, alpha-lipoic acid (ALA) has been reported to afford protection against neurodegenerative disorders in humans and experimental animals, yet little study elucidates whether it works in glaucomatous optic neuropathy. Objective This study aims to investigate whether ALA possesses neuroprotection against hydrostatic pressure-induced damage and explore its possible protective mechanism in cultured retinal ganglion cells (RGCs) in vitro. Methods RGC-5 cells were differentiated using staurosporine and pre-treated with different concentrations of ALA, then subjected to 50 mm Hg hydrostatic pressure for 6 h. After elevated hydrostatic pressure, cell viability was measured using MTT assay and apoptosis was evaluated using flow cytometry with Annexin V/PI staining. Intracellular reactive oxygen species (ROS) changes were determined by flow cytometry based on 2′,7′-dichlorofluorescein diacetate (DCFH-DA). The expression of manganese superoxide dismutase (MnSOD) was measured via quantitative real-time PCR and Western blotting analysis. Results Increases of apoptotic rate and ROS production were observed in pressure-treated RGC-5 cells compared to normal control cells. In contrast, pretreatment of ALA significantly reduced the production of ROS, increased the expression of MnSOD and prevented apoptosis in pressure-treated RGC-5 cells. Conclusions These findings suggest that there are protective effects of ALA against elevated hydrostatic pressure-induced damage in RGC-5 cells, indicating ALA might be a potential therapeutic agent for glaucomatous optic neuropathy.

Purpose: To evaluate the efficacy, safety and early visual quality of the AcrySof ReSTOR multifocal intraocular lens (IOL) following cataract surgery. Setting: Eye Center of Shandong University of Traditional Chinese Medicine, Jinan Shierming Eye Hospital, Jinan, Shandong, China. Methods:After small-incision phacoemulsification, AcrySof ReSTOR IOLs were implanted in 20 subjects (40 eyes, ReSTOR group). Monofocal IOLs were implanted in 18 subjects (36 eyes, control group). Three to six months following bilateral implantation, visual acuity, depth of focus, corneal astigmatism, contrast sensitivity, glare sensitivity, visual field and spherical aberration were compared between the groups. A subjective outcome questionnaire was also completed by the subjects. Results: Uncorrected near visual acuity 0.5 or better was achieved by 92.5% of the ReSTOR eyes. In the monofocal eyes, only 33.3% of the eyes achieved uncorrected near visual acuity of 0.5 or better. There was no statistical difference between corrected near, distance visual acuity, and uncorrected distance visual acuity in the 2 groups (p > 0.05). In patients with visual acuity 0.5 or better, the depth of focus was 4.87 ± 1.09 and 2.08 ± 0.69 dpt in the ReSTOR and control groups, respectively. The contrast sensitivity, glare sensitivity and visual field of both groups were similar (p > 0.05). The spherical aberration of the 2 groups was similar (t = –0.37, p = 0.71). Visual disturbances were minimal with only 1 patient in each group complaining of glare at night. Conclusion:The AcrySof ReSTOR multifocal IOL is a safe and effective treatment for cataracts.

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.

PURPOSE To investigate the distribution of the (CCR) and its associated factors in children. METHODS Using a random cluster sampling method, the school-based, cross-sectional Shandong Children Eye Study included children aged 4 to 18 years from the rural county of Guanxian and the city of Weihai in the province of Shandong in East China. CCR was measured by ocular biometry. RESULTS CCR measurements were available for 5913 (92.9%) out of 6364 eligible children. Mean age was 10.0±3.3 years, and mean CCR was 7.84±0.27 mm (range: 6.98 to 9.35 mm). In multivariate linear regression analysis, longer CCR (i.e. flatter cornea) was significantly associated with the systemic parameters of male sex (P

Purpose To determine the effect of 1% cyclopentolate on the refractive status of children aged 4 to 18 years. Methods Using a random cluster sampling in a cross-sectional school-based study design, children with an age of 4–18 years were selected from kindergardens, primary schools, junior and senior high schools in a rural county and a city. Auto-refractometry was performed before and after inducing cycloplegia which was achieved by 1% cyclopentolate eye drops. Results Out of 6364 eligible children, data of 5999 (94.3%) children were included in the statistical analysis. Mean age was 10.0±3.3 years (range: 4–18 years). Mean difference between cycloplegic and non-cycloplegic refractive error (DIFF) was 0.78±0.79D (median: 0.50D; range: -1.00D to +10.75D). In univariate analysis, DIFF decreased significantly with older age (P

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).