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RESEARCH STUDY

RESEARCH

Refractive Errors In a Rural Korean Adult Population: the Namil Study

AUTHOR:

Yoo YC, Kim JM, Park KH, Kim CY, and Kim T-W for the Namil Study group, Korean Glaucoma Society

SPONSOR/INSTITUTION:

YEAR PUBLISHED:

2013

PUBLICATION:

KEY HIGHLIGHTS:

  • This study was aimed at assessing the prevalence of refractive errors in rural adult Koreans.

  • The prevalence of myopia was 20.5%, of high myopia was 1.0%, of hyperopia was 41.8%, of astigmatism was 63.7%, and of anisometropia was 13.8%.

  • Myopia prevalence decreased with age and tended to transition into hyperopia with age up to 60-69 years.

  • In subjects older than 69 years, 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.

  • The prevalence of myopia and hyperopia in rural Koreans was similar to that of rural Chinese.

  • The prevalence of high myopia was lower in this sample than in other East Asian populations, and astigmatism was the most frequently occurring refractive error.

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) <−0.5 diopters (D)) was 20.5% (95% confidence interval (CI): 18.2−22.8%), of high myopia (SE <−6.0 D) was 1.0% (95% CI: 0.4−1.5%), of hyperopia (SE>+0.5 D) was 41.8% (95% CI: 38.9−44.4%), of astigmatism (cylinder <−0.5 D) was 63.7% (95% CI: 61.0−66.4%), and of anisometropia (difference in SE between eyes >1.0 D) was 13.8% (95% CI: 11.9−15.8%). Myopia prevalence decreased with age and tended to transition into hyperopia with age up to 60−69 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.