Genetic influences on macular thickness in Koreans: the healthy twin study.

PURPOSE To estimate genetic influences accounting for macular thickness in the Korean population. METHODS Study subjects were 830 healthy Korean adults (117 monozygotic twin pairs and 523 family members) from the Healthy Twin study. Macular thickness was measured with optical coherence tomography for nine subfields including the fovea, four inner quadrants (within 1 to 3 mm of the center), and four outer quadrants (within 3 to 6 mm of the center). Quantitative genetic analyses were performed to estimate the heritability of macular thickness with respect to familial correlations. RESULTS Macular thickness varied by subfield and was thinnest at the fovea and thickest at the inner superior area. Heritability of macular thickness at each subfield was 0.76, 0.73, 0.70, 0.56, 0.67, 0.70, 0.73, 0.29, and 0.36 at the fovea, inner superior area, inner inferior area, inner nasal area, inner temporal area, outer superior area, outer inferior area, outer nasal area, and outer temporal area, respectively. CONCLUSIONS Genetic factors play a significant role in determining macular thickness in the Korean population.