OPTN and glaucoma: Interestingly, an OPTN E50K mutation was identified in familial primary open-angle glaucoma (Rezaie et al, 2002) that promotes stronger interactions with TBK1 (Li et al, 2016), which in turn triggers an accumulation of insoluble OPTN and constriction of the Golgi body (Minegishi et al, 2013).