On the prevention and treatment of progressive vision loss in primary open-angle glaucoma
Primary open-angle glaucoma (POAG) is a progressive degenerative disease characterized by distinct structural changes in the optic nerve head and retinal nerve fiber layer associated with functional visual field defects. The progressive degeneration of retinal ganglion cells (RGCs) in the retina and their axons in the optic nerve underlie these changes in POAG, although the exact temporal and mechanistic relationships between structural changes, functional changes, and RGC death remain uncertain. Evidence suggests that structural changes precede progressive visual field loss, suggesting a window of opportunity for the treatment of POAG between the onset of identifiable structural changes and the threshold of significant loss of vision. In this chapter, we review the time course and mechanisms of POAG progression, including the nature and effects of primary insults, the early morphological and functional changes associated with RGC injury, and the causes and mechanisms of RGC death. We address vascular abnormalities in POAG and how they may influence or directly cause the loss of RGCs. We then highlight a conceptual model of inflammatory degeneration in POAG in which the innate immune response to RGC death initiates a vicious cycle of glial cell activation and inflammatory RGC death which propagates to surrounding regions. A better understanding of the causes, mechanisms, and time course of RGC death in POAG may lead to the development of better diagnostic techniques and neuroprotective therapies.
Glaucoma Research 2020-2022, pp. 1-16 #1
Edited by: Paul A. Knepper and John R. Samples
© Kugler Publications, Amsterdam, The Netherlands