Preschool Children Exhibit Evident Compensatory Role of Internal Astigmatism in Distribution of Astigmatism: The Nanjing Eye Study

et al. 2020

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BackgroundsTo determine the biometric components of aniso-astigmatism and associated maternal risk factors in Chinese preschool children.MethodsIn the population-based, cohort Nanjing Eye Study, children were measured for noncycloplegic refractive error using an autorefractor and for biometric parameters using an optical low-coherent reflectometry. The difference of total astigmatism (TA) between both eyes was calculated using cylinder power (non-vectorial aniso-TA was defined as ≥ 1.00 Dioptre Cylinder [DC] between both eyes) and by vector analysis (vectorial aniso-TA was defined as a difference of ≥ 0.5 in J0 or J45 between both eyes which is equivalent to 1.00 DC). The prevalence of aniso-TA was presented. Interocular biometric parameters were compared between with vs. without aniso-astigmatism group. In addition, risk factors were determined using multivariate logistic regression model.ResultsOf 1131 children (66.90 ± 3.38 months, 53.31% male), the prevalence of non-vectorial aniso-TA was 1.95% (95% Confidence Interval (CI) = 1.14%-2.75%), while the prevalence of vectorial aniso-TA was twice as common as non-vectorial aniso-TA, neither varying with sex or age. With aniso-TA eyes were more asymmetric in axial length and corneal curvature radius than without aniso-TA eyes. In multivariate logistic regression model, 5-min apgar score less than 7 was significantly associated with higher risk of aniso-TA (vectorial aniso-TA: Odds Ratio (OR) = 6.42, 95%CI = 2.63–15.69, P < 0.001; non-vectorial aniso-TA: OR = 4.92, 95%CI = 1.41–17.68, P = 0.01). Being twin or triple was significantly associated with higher risk of vectorial aniso-CA (OR = 2.43, 95%CI = 1.05–5.60, P = 0.38). Pre-term delivery (OR = 2.60, 95%CI = 1.09–6.15, P = 0.03) and post-term delivery (OR = 3.61, 95%CI = 1.31–9.96, P = 0.01) were significantly associated with higher risk of vectorial aniso-CA.ConclusionsBoth corneal curvature radius and axial length asymmetry were correlated with aniso-TA. Children with 5-min apgar score < 7 were more likely to have aniso-TA, while twin or triple, pre-term or post-term delivery were risk factors for vectorial aniso-CA.

Section: Discussioncontrasting

confidence: 50%

The biometric parameters of aniso-astigmatism and its risk factor in Chinese preschool children: the Nanjing Eye Study

et al. 2020

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“…The NES is an ongoing population-based open cohort study, designed to longitudinally observe the onset and progression of childhood ocular diseases in eastern China [9,[12][13][14][15]. The study was approved by the institutional review board in The First Affiliated Hospital with Nanjing Medical University and was conducted in accordance with the tenets of the Declaration of Helsinki.…”

Section: Study Populationmentioning

confidence: 99%

“…Previous studies have found many factors associated with astigmatism including high risk genes, eyelid pressure, extraocular muscle tension, gestational age, birth weight, nutrition [1], ethnicity, spherical equivalent refractive error, maternal smoking during pregnancy [2], accommodative convergence/accommodation ratio (AC/A) [3], age, education, ametropia [4], the axial length-corneal radius ratio (AL/CR) [5], delivery mode [6], socio-economically deprivation [7] and iris color [8]. In a recent paper on 48-60-month-old Chinese children [9], we reported the prevalence of the components of astigmatism, described the difference between corneal astigmatism (CA) and anterior corneal astigmatism (ACA), and demonstrated the compensatory role of internal astigmatism (IA) in reducing ACA. In addition, we evaluated the role of age, gender, and AL/CR on the components of astigmatism.…”

Section: Introductionmentioning

confidence: 99%

Risk factors for astigmatic components and internal compensation: the Nanjing Eye Study

et al. 2020

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Purpose To determine the risk factors for total astigmatism (TA), anterior corneal astigmatism (ACA), and internal compensation in Chinese preschool children. Methods In the population-based Nanjing Eye Study, children were measured for noncycloplegic refractive error and for biometric parameters. Data from questionnaires and measures from right eyes were analyzed for determining risk factors for TA, ACA, and internal compensation from multivariate logistic regression models. Results Of 1327 children (66.8 ± 3.4 months, 53.2% male), older age of the child (OR = 0.95 for per month increase; P = 0.03), older paternal age at child birth (OR = 1.04 for per year increase; P = 0.03), paternal astigmatism (OR = 1.89; P = 0.003), maternal astigmatism (OR = 1.73, P = 0.008), and secondhand smoke exposure during pregnancy (OR = 1.64; P = 0.03) were associated with higher risk of TA, while partial breastfeeding (OR = 0.49, P = 0.006) or formula feeding (OR = 0.46, P = 0.003) were associated with lower risk of TA. Larger ratio of axial length to corneal radius (OR = 16.16 for per unit increase; P = 0.001), maternal working during pregnancy (OR = 1.27; P = 0.04), and cesarean delivery (OR = 1.68, P = 0.04) were associated with higher risk of ACA, while formula feeding was associated with lower risk of ACA (OR = 0.57, P = 0.01). Paternal astigmatism (OR = 0.50, P = 0.01) and assisted reproduction (OR = 0.56, P = 0.03) were associated with lower risk of horizontal or vertical internal compensation. More outdoor activity time (OR = 1.15 for per hour increase, P = 0.01) was associated with higher risk of oblique internal compensation while more nighttime sleep on weekends (OR = 0.83 for per hour increase, P = 0.01) was associated with lower risk of oblique internal compensation. Conclusions Our study confirmed some previously reported risk factors and identified some novel risk factors for astigmatism including formula feeding for lower risk of both ACA and TA, and older paternal age at child birth for higher risk of TA.

“…A comprehensive questionnaire was distributed to legal guardians of each child. The examining procedures and content of the questionnaire have been described in detail previously [20,21]. The Apgar score is the most widely recognized index used to report the health status of a newborn [22], which is usually obtained by evaluating the following 5 items: appearance (color), pulse (heart rate), grimace response (re exes), activity (muscle tone) and respiration (breathing rate and effort) at one, ve and ten minutes after delivery, with the range being 0-10 [23].…”

Section: Ocular Examinations and Questionnairesmentioning

confidence: 99%

The biometric parameters of aniso-astigmatism and its risk factor in Chinese preschool children: the Nanjing Eye Study

et al. 2020

Preprint

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Backgrounds: Aniso-astigmatism may hinder normal visual development in preschool children. Knowing its prevalence, biometric parameters and risk factors is fundamental to children eye care. The purpose of this study was to determine the biometric components of aniso-astigmatism and associated maternal risk factors in Chinese preschool children.Methods: In the population-based, prospective cohort Nanjing Eye Study, children were measured for noncycloplegic refractive error using an autorefractor and for biometric parameters using an optical low-coherent reflectometry. The difference of total astigmatism (TA) between both eyes was calculated using cylinder power (non-vectorial aniso-TA was defined as ≥1.00 Dioptre Cylinder [DC] between both eyes) and by vector analysis (vectorial aniso-TA was defined as a difference of ≥0.5 in J0 or J45 between both eyes which is equivalent to 1.00 DC). The prevalence of aniso-TA was presented. Interocular biometric parameters were compared between with vs. without aniso-astigmatism group. In addition, risk factors were determined using multivariate logistic regression model.Results: Of 1131 children (66.90±3.38 months, 53.31% male), the prevalence of non-vectorial aniso-TA was 1.95% (95% Confidence Interval (CI)=1.14%-2.75%), while the prevalence of vectorial aniso-TA was twice as common as non-vectorial aniso-TA, neither varying with sex or age. With aniso-TA eyes were more asymmetric in axial length and corneal curvature radius than without aniso-TA eyes. In multivariate logistic regression model, 5-min Apgar score less than 7 was significantly associated with higher risk of aniso-TA (vectorial aniso-TA: Odds Ratio (OR)=6.42, 95%CI=2.63-15.69, P<0.001; non-vectorial aniso-TA: OR=4.99, 95%CI=1.41-17.68, P=0.01）. Being twin or triple was significantly associated with higher risk of vectorial aniso-CA (OR=2.43, 95%CI=1.05-5.60, P=0.04). Pre-term delivery (OR=2.60, 95%CI=1.09-6.15, P=0.03) and post-term delivery (OR=3.61, 95%CI=1.31-9.96, P=0.01) were significantly associated with higher risk of vectorial aniso-CA.Conclusions: Both corneal curvature radius and axial length asymmetry were correlated with aniso-TA. Children with 5-min Apgar score<7 were more likely to have aniso-TA, while twin or triple, pre-term or post-term delivery were more likely to have vectorial aniso-CA.