OPTN and open-angle glaucoma: Until now, four genes have been reported to be causative or probably causative of POAG: myocilin (MYOC, also called GLC1A) [3, 4], optineurin (OPTN, also called GLC1E) [5, 6], neurotrophin 4 (NTF4) [7, 8] and tank-binding kinase 1 (TBK1, also called GLC1P) [9–11].