OPTN and glaucoma: In summary, expression of E50K OPTN, but not OPTN that lacks the glaucoma-associated mutation, not only increases the amount of stopped mitochondria, OPTN and LC3b, and the degree of co-localization between mitochondria and OPTN within axons but also increases the amounts of mitochondria and the mitophagy receptor OPTN being found outside of the axons, much of which also co-localize outside of the axons.