Pericytes in the optic nerve head.

Pericytes are a unique population of contractile mural cells and are an essential part of the microvasculature. In the retina and brain, pericytes play crucial roles in regulating blood flow, maintaining the blood-brain barrier, signaling with neighboring cells, and depositing extracellular matrix. Pericyte dysfunction is an early process in a variety of neurodegenerative conditions. However, remarkably little is known about pericytes at an early site of neurodegeneration in glaucoma, the optic nerve head (ONH). This work summarizes the current understanding of pericyte contributions to ONH physiology, identifies potential roles in glaucomatous pathophysiology, and uncovers open questions at the intersection of these areas. We surveyed the literature to identify the roles of ONH pericytes in the context of health and glaucoma. Additionally, we probed for the presence of pericytes along microvasculature in mouse, nonhuman primate, and human donor ONH tissues. We identified an association between factors influencing ONH dysfunction in glaucoma and factors influencing pericyte dysfunction in other neurodegenerative conditions. Pericytes exist in the mouse, nonhuman primate, and human ONH, implicating their capacity for local function. ONH pericytes represent a promising but underexplored target for treating microvascular impairment in glaucoma. Investigating the contribution of pericytes in both healthy and disease states can help inform mechanisms of dysfunction in glaucomatous pathology, paving the way for the development of novel therapeutic strategies.