Abstract
Purpose :
Anisometropia is a refractive condition characterized by asymmetric growth between two eyes, despite sharing the same genetic factors and exposed to similar environmental factors. We aimed to investigate the prevalence and associated factors of anisometropia in a Taiwanese preschool population.
Methods :
This study conducted a retrospective analysis of ophthalmic examination data and questionnaires obtained from a series of repeated countywide population-based, cross-sectional surveys (YMVIP), spanning from 2014 to 2022. Anisometropia was defined as a spherical equivalence difference ≥ 1.00D between two eyes. Myopia was defined as a mean SE of ≤ -0.5D, hyperopia as a mean SE of >= 0.50D, and moderate to severe hyperopia as a mean SE of > 2.00D. Astigmatism>=1.50D was excluded from the analysis.
Results :
28,776 preschoolers aged 5-6 years underwent the examination between 2014 and 2022. After excluding subjects with incomplete refraction data (n=185), orthokeratology use (n=23) and astigmatism>=1.50D (n=4,513), a total of 24,055 preschoolers (83.6%) were included in the statistical analysis. Among them, 1,047 subjects (4.4%) were anisometropic.The mean spherical equivalence of the right eyes in the anisometropic group was 1.135 ± 1.763 diopter, compared to 0.830 ± 0.787 diopter in the isometropic group (p<0.001). The mean cylindrical measurement of the right eyes was -0.448 ± 0.429 diopter for the anisometropic group, compared to -0.335 ± 0.370 diopter for the isometropic group (p<0.001). Multinomial logistic regression analysis revealed that anisometropia was associated with myopia (OR 3.935, 95% CI 3.151 to 4.915), moderate to severe hyperopia (OR 7.464, 95% CI 6.347 to 8.778), and the post-pandemic outbreak period (examined in year 2019 to 2022, OR 1.166, 95% CI 1.024 to 1.329).
Conclusions :
Ametropia and post-pandemic outbreak period are correlated with an increased risk of anisometropia among preschoolers. Further longitudinal research is warranted to examine the impact of low-grade anisometropia on the refractive development of school-age students.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.