RESUMO
BACKGROUND: Visual recovery is an established but poorly studied phenomenon in glaucoma. OBJECTIVE: To provide insights into functional recovery of retinal ganglion cells (RGCs) with a view to providing information on the development of forms of treatment that improve RGC function after injury. METHOD: A model of recoverable RGC function in the mouse eye, induced by short-term elevation of intraocular pressure (IOP). RESULTS: The RGCs manifest near complete functional recovery after a prolonged period of dysfunction following acute IOP elevation. Increasing age and a high fat diet were subsequently found to impair recovery, whereas exercise substantially improved recovery such that older mice recovered in a similar way to young mice. CONCLUSION: Injured RGCs have the capacity to restore function after periods of functional impairment. Therapies that specifically target injured RGCs and enhance their capacity to recover function may provide a new approach for treating glaucoma.
Assuntos
Glaucoma , Animais , Modelos Animais de Doenças , Pressão Intraocular , Células Ganglionares da Retina , Tonometria Ocular , Visão OcularRESUMO
Optic neuropathies are an important cause of blindness worldwide. The study of the most common inherited mitochondrial optic neuropathies, Leber hereditary optic neuropathy (LHON) and autosomal dominant optic atrophy (ADOA) has highlighted a fundamental role for mitochondrial function in the survival of the affected neuron-the retinal ganglion cell. A picture is now emerging that links mitochondrial dysfunction to optic nerve disease and other neurodegenerative processes. Insights gained from the peculiar susceptibility of retinal ganglion cells to mitochondrial dysfunction are likely to inform therapeutic development for glaucoma and other common neurodegenerative diseases of aging. Despite it being a fast-evolving field of research, a lack of access to human ocular tissues and limited animal models of mitochondrial disease have prevented direct retinal ganglion cell experimentation and delayed the development of efficient therapeutic strategies to prevent vision loss. Currently, there are no approved treatments for mitochondrial disease, including optic neuropathies caused by primary or secondary mitochondrial dysfunction. Recent advances in eye research have provided important insights into the molecular mechanisms that mediate pathogenesis, and new therapeutic strategies including gene correction approaches are currently being investigated. Here, we review the general principles of mitochondrial biology relevant to retinal ganglion cell function and provide an overview of the major optic neuropathies with mitochondrial involvement, LHON and ADOA, whilst highlighting the emerging link between mitochondrial dysfunction and glaucoma. The pharmacological strategies currently being trialed to improve mitochondrial dysfunction in these optic neuropathies are discussed in addition to emerging therapeutic approaches to preserve retinal ganglion cell function.