Results of the School Children Ocular Biometry and Refractive Error Study in South India

Abstract

Objectives: Axial length (AL) is an important contributor to refraction, and growth curves are gaining importance in the prediction of myopia. This study aimed to profile the distribution of ocular biometry parameters and to identify correlates of spherical equivalent refraction (SE) among school children in South India. Materials and Methods: The School Children Ocular Biometry and Refractive Error study was conducted as part of a school screening program in southern India. The enrolled children underwent tests that included vison check, refraction, binocular vision assessment, and biometry measurements. Results: The study included 1382 children whose mean (standard deviation [SD]) age was 10.18 (2.88) years (range: 5-16 years). The sample was divided into 4 groups (grades 1-2, grades 3-5, grades 6-9, and grade 10) based on significant differences in right AL (p<0.001). The mean (SD) AL (range: 20.33-27.27 mm) among the four groups was 22.50 (0.64) mm, 22.88 (0.69) mm, 23.30 (0.82) mm, and 23.58 (0.87) mm, respectively. The mean SE (range: +1.86 to -6.56 D) was 0.08 (0.65 D) in class 1 and decreased with increasing grade to -0.39 (1.20 D) in grade 10. There was a significant difference in all biometry parameters between boys and girls (p<0.001). Age, AL, and mean corneal curvature were the main predictors of SE. Conclusion: This study provides a profile of ocular biometry parameters among school children in South India for comparison against profiles from other regions across the country. The study data will form a reference for future studies assessing myopia in this ethnicity.

Analysis of factors related to the development of ocular biometric parameters in Chinese children aged 6–10 years: a cross-sectional study

“…Age and sex independently predicted AL but not myopia, consistent with previous research. 5 27 This difference may be related to compensatory changes in other refractive parameters. Significant differences in ACD and corneal curvature were also observed between boys and girls in the present study, 28 29 but corneal curvature was not associated with age, 30 which is consistent with the literature, as corneal curvature reaches adult levels by the age of 3 years.…”

“…4 Disruption of this coordination leads to refractive errors such as myopia and hyperopia. [5][6][7] Ocular biometry is partly controlled by genetic background. Previous studies have shown that many of the loci associated with refraction are also associated with axial length (AL), whereas genes associated with AL are not necessarily associated with refractive error.…”