Hwang S, et al. - In this cross-sectional, twin and family study involving 362 Korean adults with healthy eyes from 79 households with two or more family members, researchers assessed genetic influence on macular retinal nerve fibre layer (RNFL) thickness. Using the variance decomposition model, heritability of RNFL thickness was assessed. According to findings, genetic factors have a significant influence on macular RNFL thickness. This differs largely through subfields with the highest heritability at the central subfield and a relatively lower heritability at inner subfields.