Abstract
Purpose :
To investigate the distributions of visual impairment and its causes in preschool children.
Methods :
A school-based study was conducted in Beijing, norther China. Distant visual acuity was measured using the Lea Symbols ETDRS 3 meter Set charts (250300, Goodlite, IL, USA) and calculated in logMAR. Ocular biometric parameters were obtained by an ocular biometry system (Lenstar LS900). Cycloplegic refraction (2 drops of 1% cyclopentolate) was measured by an autorefractor with spherical equivalent refraction (SE) calculated. According to the American Academy of Ophthalmology (AAO) guidelines, visual impairment was defined as present visual acuity (PVA) in either eye >0.4, 0.3, and 0.2 in children aged 36–47, 48–60, and 61–83 months, respectively, as well as an interocular difference (IOD) of ≥ 0.2.
Results :
Among the 1473 preschool students (97.2%) included, mean age was 4.99±0.76 years and boys accounted for 52.5%. Overall, the mean cycloplegic SE, axial length (AL) and axial length to corneal radius ratio (AL/CR) for better eyes was 1.27±0.83D, 22.23±0.69mm and 2.86±0.07. The prevalence of myopia, emmetropia and hyperopia was 1.9%, 84.1% and 14.0%, respectively. A total of 265 (17.99%) children were found to have reduced PVA in the worse eye, and 26 (1.77%) of the children had an IOD of two or more lines. PVA in preschool children improves with age naturally, while no significant difference exists between boys and girls. In the univariate analysis, myopia, anisometropia, astigmatism, pseudomyopia ,amblyopia were risk factors for visual impairment statistically (OR=40.0, 10.93, 5.57, 1.83, 1.46, respectively; P<0.05 for all). In the multivariate logistic regression, age, myopia, anisometropia, astigmatism and amblyopia were still correlated with visual impairment.
Conclusions :
This study provided data on the prevalence and distribution of visual impairment, refractive errors and ocular biometry in preschool children in China. Among all the factors, refractive errors turn to be the main cause for visual impairment. Meanwhile, the data also suggested that appropriate and timely vision screening project in preschool children should be meaningful for effective prevention.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.