Glaucoma: Silent Cause of Vision Loss









By Hans Petersen, VA Staff Writer

Monday, January 5, 2015

January is Glaucoma Awareness Month, a time to remind all Veterans to take action now to prevent this sight-stealing disease.

One-and-a-half million Veterans have a vision threatening eye disease, including 285,000 with glaucoma.

African-American Veterans should especially get their eyes checked regularly as glaucoma is six-to-eight times more common in African-Americans than Caucasians.

Also, among Hispanic populations, glaucoma is the leading cause of blindness.

Starts without Symptoms

What is glaucoma? Glaucoma is a group of eye diseases in which the optic nerve, a bundle of over one million nerves that convey vision from the eye to the brain, slowly becomes damaged over time. In many cases, blood flow to the optic nerve is reduced and may be further reduced by increased fluid pressure inside the eyes slowly rising, leading to vision loss or even blindness.

The highest risk group is those Veterans over 60. Other risk factors include hypertension, but also too-low blood pressure, especially during the hours of sleep. Some patients who take blood pressure medicine at bedtime, may be at risk of dropping their blood pressure too low during sleep, reducing blood flow to the optic nerves. In addition, patients with obstructive sleep apnea who are untreated may have further risk for glaucoma-related damage to their optic nerves due to drops in oxygenation when they momentarily stop breathing during sleep.

Glaucoma usually starts without any symptoms. Later, there is some loss of side vision, where objects straight ahead are seen clearly, but objects to the side are missed. As the disease worsens, the ability to see objects on the side is increasingly lost and eventually the center of vision is affected.

The test for glaucoma is painless. Your VA doctor will test the pressure in your eye by placing an instrument on its surface. If there is a suspicion for glaucoma, the appearance and function of the optic nerve are tested with a visual field test and a special retina camera both of which can detect damage to the optic nerves.

Glaucoma is treated with eye drops, but in some cases, eye surgery is necessary to optimally lower the eye pressure. These treatments work to either make less fluid or to improve its drainage out of the eye.

Glaucoma is a life-long problem. Veterans should have regular check-ups by an ophthalmologist or optometrist to watch for changes in pressure and side vision.

It is so important for Veterans to have regular eye exams.

Cutting Edge Research

VA is working hard to help prevent Veterans’ eye problems at the VA Center for the Prevention and Treatment of Visual Loss based at the Iowa City VA.

The Center conducts innovative research in the diagnosis of visual loss and works to understand the underlying mechanisms and causes of visual loss. With this research, the center can study new approaches toward rehabilitation and treatment of visual loss, while improving education and clinical care of our nation’s Veterans.

According to Dr. Randy H. Kardon, director of the center, “Glaucoma is one of the silent causes of vision loss. Patients are unaware that they are slowly losing vision until it is too late, at which time the loss is permanent. That is why it is so important for Veterans to have regular eye exams to check for any sign that glaucoma is developing and to be treated, if glaucoma is detected.”

VA spends a significant portion of its medical care dollars toward detecting and monitoring of treatment of vision loss. Last year there were more than 2.9 million Veteran visits in VA eye care optometry and ophthalmology clinics.

Remote Monitoring of Optic Nerve Structure and Function

The Center of Excellence for the Prevention and Treatment of Visual Loss is working to reduce the cost of monitoring through new methods of detection, understanding the underlying mechanisms of disease, developing new molecular treatments to preserve vision, and telemedicine initiatives.

Center Associate Director Dr. Michael Abramoff and his colleagues, including investigator Mona Garvin, Ph.D., are developing portable digital eye cameras along with cutting-edge software that automatically analyze images of the optic nerve to diagnose glaucoma and determine if it is changing with time. Investigators from the Center are recording blood flow to the retina and optic nerve using a new research eye camera utilizing non-invasive imaging to quantify the blood supply to the optic nerve.

Center investigators are also developing computerized methods of testing optic nerve function using the eye’s pupil contraction to light, termed the “pupillary light reflex.” Remote pupil testing is being developed to monitor optic nerve function and status of glaucoma outside of the eye clinic setting.

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