The study was done to evaluate genetic influence on macular GCIPL thickness.

Macular GCIPL thickness was measured with optical coherence tomography in nine macular subfields defined by the E TDRS. Three hundred and sixty-one Korean adults from 89 families with normal healthy eyes were included. GCIPL thickness was highest in inner subfields and lowest in fovea. Monozygotic twin pairs showed significantly higher ICCs of GCIPL thickness in all subfields compared to those in parent–offspring pairs and sibling pairs. GCIPL thickness was highly heritable in the centre (0.71) and outer subfields but moderate to highly heritable in inner subfields. Heritability of GCIPL thickness in outer subfields was 0.69, 0.67, 0.72 and 0.68 for superior, inferior, temporal and nasal fields, respectively. Heritability of GCIPL thickness in inner subfields was 0.55, 0.56, 0.75 and 050 for superior, inferior, temporal and nasal subfields, respectively.

The study concluded that the macular GCIPL thickness is significantly influenced by genetic factors. It varies according to subfields with moderate to high heritability in all subfields.