Glaucomatous optic neuropathy: Mitochondrial dynamics, dysfunction and protection in retinal ganglion cells

Glaucoma is a leading cause of irreversible blindness worldwide and is characterized by a slow, progressive, and multifactorial degeneration of retinal ganglion cells (RGCs) and their axons, resulting in vision loss. Despite its high prevalence in individuals 60 years of age and older, the causing factors contributing to glaucoma progression are currently not well characterized. Intraocular pressure (IOP) is the only proven treatable risk factor. However, lowering IOP is insufficient for preventing disease progression. One of the significant interests in glaucoma pathogenesis is understanding the structural and functional impairment of mitochondria in RGCs and their axons and synapses. Glaucomatous risk factors such as IOP elevation, aging, genetic variation, neuroinflammation, neurotrophic factor deprivation, and vascular dysregulation, are potential inducers for mitochondrial dysfunction in glaucoma. Because oxidative phosphorylation stress-mediated mitochondrial dysfunction is associated with structural and functional impairment of mitochondria in glaucomatous RGCs, understanding the underlying mechanisms and relationship between structural and functional alterations in mitochondria would be beneficial to developing mitochondria-related neuroprotection in RGCs and their axons and synapses against glaucomatous neurodegeneration. Here, we review the current studies focusing on mitochondrial dynamics-based structural and functional alterations in the mitochondria of glaucomatous RGCs and therapeutic strategies to protect RGCs against glaucomatous neurodegeneration.