Increased eye pressure often occurs in glaucoma, a blinding eye disease that affects about 70 million people worldwide, and the new findings may have implications for treating this disease. The study currently appears in the online October issue of the Journal of Cellular Physiology.
"Pressure is required in the eye to keep its shape, and this pressure is maintained in the front part of the eye by a fluid, the aqueous humor," said Dr. Teresa Borrs, the paper's senior author and professor of ophthalmology in UNC's School of Medicine. From 1997 to 2002, Borrs held a Research to Prevent Blindness Jules and Doris Stein Professorship Award.
The aqueous humor is created by the ciliary body, a tissue beneath the eye's iris. The fluid flows around the iris and out through the trabecular meshwork, or TM, a spongy tissue that provides resistance and maintains the pressure, Borrs said.
Often in glaucoma, the TM stops working and fluid builds up within the eye, causing pressure inside the eye to rise. When this happens, the optic nerve in the back of the eye can become squeezed. As this is the area that carries the visual signals from eye to brain, vision loss can occur, Borrs said.
In earlier studies, Borrs and her research group had shown that a greater outflow of fluid occurred when researchers artificially increased the pressure in human donor eyes.
"It was like the TM had a homeostatic counteracting mechanism that could sense an increase in pressure and open up a little bit, to help move the fluid out of the eye," said Borrs.
However, it was unclear how the TM achieved this pressure regulation. This study was aimed at measuring what genes were turned on or off in the TM after the pressu
Contact: Leslie H. Lang
University of North Carolina School of Medicine