The Usefulness of Duochrome Test for Prevention of Overcorrection in Refraction Tests of Myopic Children

ABSTRACT

PURPOSE: This study investigates the usefulness of the duochrome test for the prevention of overcorrection in refraction tests of myopic children. METHODS: This prospective study comprises 44 subjects (88 eyes, aged 6 to 10 years) with simple myopia and best-corrected visual acuity of 20/20. After the manifest refraction (MR) was measured with an autorefractometer (KR-8100, Topcon), the refractive error of the duochrome test (DR) was measured at the end point when targets of red and green appeared equally clear. The cycloplegic refraction (CR) was then measured. A statistical analysis and comparison of MR, DR, and CR were conducted using a paired t-test. With strabismus, amblyopia and astigmatism (>or=0.5D), it was excluded. RESULTS: The mean age of the subjects was 8.7+/-1.70 years (range, 6 to 12 years). Mean refractive errors found by MR, DR, and CR were -1.9D+/-0.89 (range, -0.75 to -4.75D), -1.5D+/-0.83, -1.5D+/-0.85 in the right eye, respectively. Those found by MR, DR, and CR in the left eye were -2.0D+/-0.79 (range, -0.75 to -4.75D), -1.7D+/-0.76, and -1.6D+/-0.77, respectively. Differences in the refractive errors of MR and DR, MR and CR were statistically significant (p=0.000, p=0.000 respectively), but there was no statistically significant difference between the refractive errors of DR and CR.(p=0.102) CONCLUSIONS: We found the duochrome test to be an easy and simple method to prevent overcorrection of myopia.