To date, several genes including myocilin (MYOC), optineurin (OPTN), WD repeat domain 36 (WDR36), and cytochrome P450, family 1, subfamily B, polypeptide 1 (CYP1B1) have been implicated in POAG, but mutations in these genes account for less than 10% of POAG cases [7-10]. Here, OPTN is linked to open-angle glaucoma.