Combatting glaucoma

04/25/2014 4:18 PM

04/25/2014 4:19 PM

Glaucoma is a growing phenomenon.

Fifty percent of people with the age-associated eye disease don’t know they have it, and in the United States, it is the most common cause of irreversible vision loss in the black community.

“The fastest-growing [glaucoma] population in Miami is in the Haitian population,” said Dr. Richard Lee, associate professor of ophthalmology, cell biology and anatomy and neuroscience at the University of Miami’s Bascom Palmer Eye Institute. “But so far, there’s no glaucoma that’s curable and preventable.”

That’s why Lee has focused his research on what causes the degenerative eye disease. His research, backed by the National Institute of Health, includes breaking down protein compounds to molecular levels to see what proteins are interacting, and what genes may be present in the proteins to provoke the disease.

“The primary cause is high pressure in the eye, but we don’t know why,” he said. “We can prevent glaucoma from getting worse by lowering pressure, but that doesn’t prevent the root cause.”

Glaucoma is the deterioration of the optic nerve. Increased pressure in the eye — a pressure similar to blood pressure — leads to a loss of tissue around the optic nerve, which enlarges and exposes it. The optic nerve is a key player in transmitting visual information to the brain.

“The optic nerve is an extension of the brain,” said Lee. “And cells that die don’t recover.”

There are primary and secondary forms of glaucoma. Primary means doctors can’t find a reason behind the high pressure. In the secondary forms, there are visible reasons for the pressure, but the cause of those reasons remains unknown.

Lee’s research focuses on the most common form of secondary glaucoma: pseudoexfoliation glaucoma or PXE.

“In [PXE] material forms around the eye that’s present throughout the body: white, flaky, dandruff-y material,” said Lee, adding the material is a culmination of various proteins. “It falls in the drainage channel of the eye and clogs it like a kitchen sink. It’s all over the body, but the only place known to cause disease is in the eye.”

By drawing a patient’s blood and collecting fluid and tissue where the material is deposited in the eye, Lee is working to find how the molecules of the different proteins interact.

“If we can figure out what this protein complex is and prevent proteins from interacting, maybe we can prevent this disease from happening,” Lee said.

A main part of analyzing the proteins involves finding what genes are present in them.

“If you look at an Asian person, black or white person, 99.9 percent of the DNA is the same,” said Lee. “That 0.1 percent is the difference between Barack Obama and Bush, and those little differences are what we are looking at to see the risk factors.”

Lee said the goal is to find a genetic link that will lead doctors to screen people before they develop the disease.

Brian O Neil, 75, was diagnosed with glaucoma about 15 years ago. He also has cataracts — the normal aging of the eye’s lens — and was operated for a melanoma tumor in his left eye nearly three years ago.

Lee began treating O Neil six years ago; he is one out of hundreds of patients participating in the PXE study.

“He is interesting because [PXE] patients tend to have a higher risk of complications associated with cataract surgery,” said Lee of O Neil, who had cataracts removed and his lenses replaced in both eyes roughly two years ago.

Lee said the excess material caused by PXE can cause intrinsic weaknesses in the eye, but in O Neil’s case, the cataracts’ removal improved the eye pressure, which contributes to his glaucoma.

“If I lost my sight, my quality of life would be really, really lousy and I’m not sure I would want to go through that,” said O Neil. “The breakthroughs in medicine, which are just unbelievable, are from studies, so why not [participate]? Maybe I can help.”

O Neil, who grew up in Florida, said his mother had glaucoma. The genetic link Lee hopes to discover through his research could explain why glaucoma is inherited. Lee said the research still has a long way to go and that the study is still accepting patients.

“Right now they’re waiting for people to get [glaucoma] to then treat it,” Lee said. “If we find this material, we can pre-treat these people.”

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