■ Reduced blood flow and impaired neurovascular coupling are well known features of glaucoma. New research reported in the Proceedings of the National Academy of Sciences reveals that nanotubes connecting pericytes are damaged in glaucoma leading to neurovascular deficits.

Pericytes — cells that can control the amount of blood passing through a single capillary by squeezing and releasing it — are wrapped around the capillaries. Calcium entry into pericytes regulates their ability to constrict capillaries and control blood flow. In glaucoma, pericyte calcium influx is excessive, causing decreased blood supply.

“We show that pericyte dysfunction impairs blood supply, causing the death of retinal ganglion cells, the neurons that connect the retina with the brain, ultimately leading to vision loss,” said Adriana Di Polo, professor of neuroscience and ophthalmology at Université de Montréal, in a news release. This study paves the way for the development of therapeutic approaches that selectively target pericytes and calcium equilibrium to restore neurovascular health in glaucoma and potentially other neurodegenerative disorders with vascular components.