Changes of Refractive Errors and Optometric Values in Fourth Graders at an Urban Elementary School in Korea

ABSTRACT

PURPOSE: To evaluate changes in refractive errors and quantify optometric values in 4th graders at an urban elementary school in Korea. METHODS: A total of 188 school children (376 eyes) were assessed in a population-based, cross-sectional and longitudinal follow-up study between March and December 2003. Uncorrected visual acuity, best corrected visual acuity, corneal refractive power measured with auto keratometer (KR-8100, Topcon(R) Inc., Japan), axial length measured with A-scan ultrasound biometry (A/B-scan system 835, Humphrey(R) Inc., Dublin, CA), and cycloplegic refraction were evaluated on March and December, respectively. RESULTS: Mean visual acuity decreased from -0.15+/-0.29 LogMAR to -0.20+/-0.35 LogMAR and mean spherical equivalent (SE) showed myopic progression from -0.65+/-1.57 diopter (D) to -0.88+/-1.75D. The prevalence rate of myopia ( or =+1.00D SE) was decreased from 8.0% to 5.8%. Mean corneal refractive power changed from 43.21+/-1.29D to 43.35+/-1.31D, and mean axial length changed from 23.38+/-0.88 mm to 23.60+/-0.92 mm, respectively. CONCLUSIONS: We assessed the changes of refractive errors and quantified the optometric values in a population-based, longitudinal follow-up study. The results showed that the prevalence of myopia and the mean axial length increased during our study in urban elementary 4th graders in Korea.