In this study, although no statistically significant differences in genotype and allele frequencies were found between POAG patients and control subjects as previous studies have reported [7,15,26], approximately 30% of POAG patients had the TT/GG high-risk compound genotype for XFS in LOXL1. It was also found that exfoliation materials that form before any clinical signs of XFS may affect phenotypic features including maximum IOP in patients with POAG. Here, LOXL1 is linked to open-angle glaucoma.