Tears Could Provide Clues to Glaucoma Diagnosis

■ While some glaucoma patients have classic high pressure inside the eye, others with glaucoma do not, says Ashok Sharma, PhD, of the Medical College of Georgia (MCG) at Augusta University, whose research team is working to associate the protein profile present in the eye’s fluid with the obvious structural damage to the eye glaucoma causes. Their goals are to find a better way to diagnose the disease, monitor its progress, and find new treatment targets. If they do, the eye’s tears may one day provide the fluid needed to perform such tests.

Dr. Sharma is principal investigator on a $1.5 million grant from the National Institutes of Health that is enabling examination over the next 4 years of the aqueous humor of 200 patients with glaucoma and 400 with cataracts serving as controls.

They are comparing the protein profile in the millionth of a liter of aqueous humor, found in the eye and removed as part of surgery, with clinical data, like images of a misshapen optic nerve and other demographic and health data like age and race, to begin to write a proteomic signature for glaucoma.

“Probably half the people who have glaucoma do not have intraocular pressures above average,” Kathryn Bollinger, MD, ophthalmologist, glaucoma specialist, and retinal cell biologist in the MCG Department of Ophthalmology, said in a university news release. Conversely, some patients who have high IOP don’t have glaucoma. While the bottom line is damage to the neurons in the eye, the level of IOP that causes damage varies in different people, Dr. Bollinger said.

“That is part of the reason why these studies are so important, because we don’t have a clear diagnostic indication for glaucoma based simply on intraocular pressure,” added Dr. Bollinger.