Background/Purpose:To assess the prevalence of nonstrabismic accommodative and vergence dysfunctions among primary schoolchildren in Hampyeong, a rural area of South Korea.Methods:Five hundred and eighty-nine primary schoolchildren, 8–13 years old, were each given a thorough eye examination, including binocular-vision testing, near point of convergence, horizontal phoria measurement by von Graefe, and negative and positive vergence amplitudes with prism bar, to determine any form of accommodative or vergence dysfunctions.Results:Of the 589 participants examined, 168 (28.5%) primary schoolchildren presented some form of nonstrabismic accommodative or vergence dysfunctions. The prevalence of accommodative dysfunctions and vergence dysfunctions was 13.2% and 9%, respectively. Convergence insufficiency (10.3%) was more prevalent than convergence excess (1.9%), and accommodative insufficiency (5.3%) was more prevalent than accommodative excess (1.2%).Conclusion:This study suggests that nonstrabismic accommodative and vergence dysfunctions are prevalent in the rural area of South Korean primary schoolchildren, and convergence insufficiency was the most prevalent.
Background/Purpose:To assess the distribution of near point of convergence (NPC), near heterophoria, and near vergence among myopic school children in South Korea.Methods:One hundred and thirty-six elementary school children, aged 8–13 years, were each given a thorough eye examination including binocular vision testing, NPC using standard push-up technique, horizontal heterophoria measurement by Von Graefe, distance, and near negative and positive vergence with a phoropter and phoropter replacement card.Results:NPC break and recovery points were highest in the age 9 years group, but the mean values of NPC were within the normal range. Of 136 individuals, 52 presented with esophoria, 53 presented with 0 –6-Δ exophoria, and 31 presented with ≥7-Δ exophoria. In the younger age groups (8 years and 10 years) 0–6-Δ exophoria was prevalent, whereas in the older age groups (11 years, 12 years, and 13 years) esophoria was prevalent. Near positive fusional vergence (break and recovery point) presented with statistically significant correlations with the participants’ ages. Esophoria showed higher correlations with high myopia (8.00 ± 0.000) rather than with low myopia (3.36 ± 2.499) or medium myopia (3.42 ± 2.149). The mean value of 0–6Δ exophoria was highest in medium myopia (4.04 ± 1.517), and of ≥7-Δ exophoria was the highest in high myopia (12.66 ± 1.154).Conclusion:There were no statistically significant correlations between the school childrens’ ages and NPC, near horizontal heterophoria, and near fusional vergence, except near positive fusional vergence. Also, unlike many studies, myopic magnitude did not present a significant correlation with near phoria and fusional vergence.
To assess the prevalence of refractive errors among elementary school children in South Jeolla Province of South Korea. Methods: The subjects were aged 8-13 years; a total of 1,079 elementary school children from Mokpo, South Jeolla Province, were included. In all participants, uncorrected visual acuity and objective and subjective refractions were determined using auto Ref-Keratometer and phoropter. A spherical equivalent of-0.50 diopter (D) or worse was defined as myopia, +0.50 D or more was defined as hyperopia, and a cylinder refraction greater than 0.75 D was defined as astigmatism. Results: Out of 1,079 elementary school children, the prevalence of uncorrected, best-corrected, and corrected visual acuity with own spectacles of 20/40 or worse in the better eye was 26.1%, 0.4%, and 20.2%, respectively. The uncorrected visual acuity was 20/200 or worse in the better eye in 5.7% of school children, and 5.2% of them already wore corrective spectacles. The prevalence of myopia, hyperopia, and astigmatism was 46.5% (95% confidence interval [CI]: 43.56-49.5), 6.2% (95% CI: 4.92-7.81), and 9.4% (95% CI: 7.76-11.25), respectively. Conclusion: The present study reveals a considerably higher prevalence of refractive error among elementary school children in South Jeolla Province of South Korea, exceeding 50% of subjects. The prevalence of myopia in the school children in Korea is similar to many other countries including People's Republic of China, Malaysia, and Hong Kong. This may indicate that genetics and educational influences, such as studying and learning, may play a role in the progression of myopia in Korean elementary school children.
This study was designed to be used as the basic visual function data after analyzing and investigating the refractive errors variation between city and rural elementary school children. Methods: To compare with city and rural areas, 2501 elementary school children who lived in Mokpo, Yeongam, Muan, Hampyeong were participated. Objective refraction, Subjective refraction and binocular function examinations were measured. Results: Mean of refractive error of rural areas was −1.47
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