Professor Susmit Suvas was awarded a five-year $1.8 million grant from the National Eye Institute at the Institutes of Health to study a new treatment for herpetic stromal keratitis.

Suvas, who teaches immunology in the department of biological sciences, was previously awarded a two-year grant to gather preliminary data on the effect of neuropeptide treatments which led to this grant.

Herpetic stromal keratitis is caused by herpes simplex virus type I (HSV-1) known to most people as the virus that causes cold sores. Suvas said however that since the virus stays in the ganglion, an area underneath the brain, it can affect three different branches of the body.

“When we get a cold sore, then the virus is coming out of sleep in the ganglion and travels to that branch, that’s the one that comes to the face, called the maxillary branch,” he said. “If the virus takes another path, the path that comes to the cornea, it will start causing inflammation.”

If the virus makes its way to the eye three or four times, it can start to cause chronic inflammation and blindness. The very cells intended to fight infection turn on the body.

“What was known in the field is that the virus comes into the cornea, causes damage to the cornea and brings in the immune cells, the cells that fight off infection,” Suvas said.  “They come into the cornea and cause corneal tissue damage. A normal cornea is clear- light can pass through the cornea, strike the retina and we see it. After the inflammation, the cornea becomes opaque. It’s cloudy.”

According to the National Institutes of Health, there are approximately 1.5 million cases of HSV-induced keratitis worldwide with 40,000 new cases of visual impairment or blindness in one eye each year.

P could mean progress

The current treatment for this disease is a cortical steroid. However, used continually, the treatment has side effects.

Suvas plans to use an antagonist of Substance P, a key controller of inflammation in the body, to bring the infection under control.

Although the treatment could eventually be delivered by eyedrops, the treatment is currently being tested in mice.

Tiny test subjects

Shravan Chintala, an associate professor of biomedical sciences at the Eye Research Institute, said the identical eye structure makes mice ideal test subjects.

“The only difference between mice and humans is that mice are nocturnal,” Chintala said.

A special microscope enables researchers to see to the back of the eye of the mouse.

All animal research must be approved by the Institutional Animal Care and Use Committee (IACUC). There is an animal care facility on campus.

Chintala breeds mice with glaucoma for his research on potential cures for the disease. He explained glaucoma is caused by a buildup of pressure in the eye.

“The disease occurs because the pressure in the eye actually increases because there is a fluid every day that is produced, but it doesn’t leave the eye,” he said. “There is a plumbing system which actually takes care of that fluid, but in some people it doesn’t happen.”

Chintala has identified a key protein associated with the vision impairing disease.

“There is a protein called SARM1, because of the pressure this SARM1 protein grows up in the retinas and this SARM1 protein actually kills (retinas),” Chintala said.