Refractive errors in a rural Korean adult population: the Namil Study

Abstract

Purpose To assess the prevalence of refractive errors, including myopia, high myopia, hyperopia, astigmatism, and anisometropia, in rural adult Koreans. Methods We identified 2027 residents aged 40 years or older in Namil-myeon, a rural town in central South Korea. Of 1928 eligible residents, 1532 subjects (79.5%) participated. Each subject underwent screening examinations including autorefractometry, corneal curvature measurement, and best-corrected visual acuity. Results Data from 1215 phakic right eyes were analyzed. The prevalence of myopia (spherical equivalent (SE) o À 0.5 diopters (D)) was 20.5% (95% confidence interval (CI): 18.2 À 22.8%), of high myopia (SE o À 6.0 D) was 1.0% (95% CI: 0.4 À 1.5%), of hyperopia (SE4 þ 0.5 D) was 41.8% (95% CI: 38.9 À 44.4%), of astigmatism (cylinder o À 0.5 D) was 63.7% (95% CI: 61.0 À 66.4%), and of anisometropia (difference in SE between eyes 41.0 D) was 13.8% (95% CI: 11.9 À 15.8%). Myopia prevalence decreased with age and tended to transition into hyperopia with age up to 60 À 69 years. In subjects older than this, the trend in SE refractive errors reversed with age. The prevalence of astigmatism and anisometropia increased consistently with age. The refractive status was not significantly different between males and females. Conclusions The prevalence of myopia and hyperopia in rural adult Koreans was similar to that of rural Chinese. The prevalence of high myopia was lower in this Korean sample than in other East Asian populations, and astigmatism was the most frequently occurring refractive error.

Global Epidemiology of Myopia

“…In this study, the prevalence of myopia was nearly the same as those in urban areas of China, while the prevalence of HM was similar to that reported in rural areas of other Asian countries. In South Korea, the prevalence of myopia and HM was 20.5% and 1.0%, respectively, among adults above 40 years in the Namil Study [74]. Relatively low prevalence in the study was reflected by rural lesions, it was similar to that of rural Chinese population.…”

<p>Biometric Parameters and Corneal Astigmatism: Differences Between Male and Female Eyes</p>

“…Yoo et al 19 analyzed data from 1215 phakic right eyes, measuring non-cycloplegic refraction and corneal curvature with an autorefractometer. The mean astigmatic refractive error in the study sample was −0.98±0.77 D. In total, 63.7% and 34.8% of the patients had refractive astigmatism (RA) >−0.5 D and >−1.0 D, respectively.…”

Racial Differences in the Extracellular Matrix and Histone Acetylation of the Lamina Cribrosa and Peripapillary Sclera

“…16 Both countries have a high prevalence of myopia. 34,35 This is in contrast with Western countries, where NTG is reported to comprise approximately 20% to 50% of the total glaucoma cases, and approximately 10% to 30% is associated with myopia. [36][37][38] Studies of Korean glaucoma patients revealed that the posterior sclera and the LC were thinner in NTG eyes compared to glaucomatous eyes with high IOP.…”