Making Vision Cells Stress Resistant

One aspect of glaucoma has long puzzled researchers. Although increased pressure in the eye is an early warning sign of glaucoma, and reducing this pressure can help reduce the risk of disease, many people still develop glaucoma-related vision loss without experiencing an increase in eye pressure. This suggests that glaucoma involves other kinds of stresses on vision cells, beyond injuries directly due to increased pressure.

Jeremy Sivak’s research studies the communications amongst cells in the retina when a person has early signs of glaucoma. This includes signals about mechanical injuries related to increased pressure, but his research speculates that other types of stress also play a role in this disease. In particular, his research has examined signals of metabolic stress, meaning that the cells of the retina are struggling to get enough oxygen and nutrients

        Dr. Sivak aims to help retinal ganglion cells (stained green) resist stress.

Retinal ganglion cells are the vision cells damaged in people with glaucoma. These cells work constantly to supply enough oxygen and nutrients for vision needs, and may be taxed by this constant activity and/or limited blood flow. This is called metabolic stress. Dr. Sivak has shown that a cellular signal, called PGC-1α, controls a cascade of protective responses when the retinal ganglion cells are threatened by metabolic stress. His research suggests that these signals may be important in protecting retinal ganglion cells from glaucoma-associated damage.

Dr. Sivak has a background in drug development and is already working towards pharmaceutical treatments that might modify PGC-1α levels, and protect retinal ganglion cells. By tracing the underlying causes of cell stress and damage in the eyes of people with glaucoma, Dr. Sivak is creating new possibilities for more effective glaucoma therapy.

Dr. Sivak’s research in this area is support by grants from the National Science and Engineering Research Council, and the Glaucoma Research Society of Canada.