Intraocular Pressure Insights

Researchers have uncovered some of the mechanics of how intraocular pressure is regulated at the cellular level.

The aqueous humor of the eye responds to mechanical stimuli at the cellular level to regulate intraocular pressure (IOP), researchers at the Bascom Palmer Eye Institute of the University of Miami’s Miller School of Medicine have found. The mechanism by which cells convert these stimuli into chemical activity involves the protein cochlin.

The findings, detailed in a study published in the April 4, 2012, issue of PLoS One, were facilitated by the fact that the Bascom Palmer Eye Institute has its own mass spectrometer, a rarity for an eye center. Cochlin is only visible in the trabecular network using mass spectrometry.

Although not all people with glaucoma have elevated IOP, many do, so lowering IOP is a primary treatment goal. “With elevated IOP being the primary modifiable risk factor affecting the development and progression of glaucoma, this advancement opens up potential avenues for effective and innovative manipulation of the pathway of aqueous outflow using mechanosensors [which respond to mechanical stimuli at the cellular level] and mechanotransducers [which convert stimuli into chemical activity],” said study coauthor Richard K. Lee, MD, PhD, in a press release. “In turn, it could lead to meaningful intervention strategies.”

The researchers found that TREK-1 mechanotransducers on the cell surface stimulate chemical signals to change fluid flow. (TREK-1 is a protein in the trabecular meshwork). Aberrant cochlin levels disrupt aqueous outflow, driving IOP up.

“Fluctuations of IOP can alter cells of the trabecular meshwork,” said another of the study’s authors, Sanjoy Bhattacharya, MTech, PhD, in the press release. “This results in dysfunction of aqueous flow. Presently, there are over 2 million known proteins and 46,000 lipids that can be tested to determine their impact upon IOP.”

Ms. Wick is a visiting professor at the University of Connecticut School of Pharmacy and a freelance writer from Virginia.