Discovery shows promise for treatment of glaucoma

In a new study from Lawson Health Research Institute (Lawson), scientists have discovered that a specific protein has the potential to be used to treat some patients with primary open-angle glaucoma.

Primary open-angle glaucoma is the most common type of glaucoma, which is a group of diseases that affect nearly 70 million people worldwide. Glaucoma is characterized by progressive damage to the optic nerve which ultimately leads to blindness. In this new study, led by Dr. Sunil Parapuram, researchers examined the role of a protein called “phosphatase and tensin homolog” (PTEN) in the trabecular meshwork. The trabecular meshwork is a porous tissue in the eye through which the clear fluid that fills the eye drains out.

In some primary open-angle glaucoma patients, the structure of the trabecular meshwork is damaged by fibrosis. Fibrosis is a thickening or scarring of tissue which is caused by an excess amount of matrix molecules such as collagen. Fibrosis of the trabecular meshwork prevents the fluid in the eye from draining out normally, which leads to increased pressure in the eye and damage to the optic nerve.

Dr. Parapuram’s team found that the inactivation of the protein PTEN can cause too many matrix molecules to be deposited in the trabecular meshwork, leading to fibrosis. On the other hand, when PTEN activity was increased, it reduced the amount of matrix molecules being deposited in the trabecular meshwork. These results indicate that drugs that can activate PTEN have high potential to be used as a treatment for open-angle glaucoma.

“There’s an immediate need for a new generation of therapeutic drugs for more effective treatment of glaucoma,” says Dr. Parapuram, a Lawson scientist at St. Joseph’s Health Care London and an assistant professor in the Departments of Ophthalmology and Pathology at the Schulich School of Medicine & Dentistry, Western University. “While further research is needed, drugs that activate PTEN could be the answer.”

Dr. Parapuram’s team will continue to study the function of PTEN in the trabecular meshwork in more detail and test the role of drugs that activate the protein as a potential treatment for primary open angle glaucoma.

Dr. Michael Motolko (left), Chair/Chief, Department of Ophthalmology, and Dr. Sunil Parapuram (right).

“This study highlights the expansion of our department’s research activities into basic science application and its findings are relevant to many other fibrotic diseases,” says Dr. Michael Motolko, Chair/Chief, Department of Ophthalmology, Schulich School of Medicine & Dentistry,Western University, London Health Sciences Centre and St. Joseph’s Health Care London.

The study, “TGF-β induces phosphorylation of phosphatase and tensin homolog: implications for fibrosis of the trabecular meshwork tissue in glaucoma,” is published in Nature’s Scientific Reports.