Glaucoma is the main cause of irreversible blindness in the world. In most common types of the disease, the optic nerve is damaged by an increase in intraocular pressure (IOP) which blocks fluid drainage through canals in the eye. There is currently no cure, however, the disease can be treated by lowering IOP. Unfortunately, all IOP-lowering drugs that in the market today target the secondary drainage pathway which mediates only 5-15% of fluid outflow. Therefore, the main goal in glaucoma research has been to identify targets in the primary outflow pathway mediated through the trabecular meshwork tissue. David Krizaj’s group at the Moran Eye Institute (University of Utah School of Medicine) has done just that.
In a paper just published in Scientific Reports, they identify TRPV4, a mechanosensitive ion channel, as the main trabecular target of increased IOP. This highly collaborative project combined genetic, molecular, whole animal approaches with bioengineered nanoscaffold models of glaucoma and drug discovery to show that activation of the channel mimics the trabecular changes in glaucoma whereas elimination of the TRPV4 gene or systemic exposure to TRPV4 inhibitors protected mice from the disease. In collaboration with Glenn Prestwich’s group in Medicinal Chemistry at the University of Utah, the team synthesized new eye drops which lowered IOP to levels seen in control mice. By targeting the primary outflow pathway, this study promises to bring new, effective cures that complement current glaucoma treatment. The primary authors of the study are Dr. Dan Ryskamp, Amber Frye and Dr. Tam Phuong.