Using relatively non-invasive technology to test for glaucoma and retinal disease is catching the diseases earlier.

One of the latest tests — Optical Coherence Tomography (OCT) — allows ophthalmologists to look at the optic nerve and retina in a manner that picks up subtle disease changes well before a doctor can see them with a traditional evaluation.

"Glaucoma can damage your vision so gradually you may not notice any loss of vision until the disease is at an advanced stage," said Dr. Mark Bateman, a board-certified ophthalmologist who practices at the Eye Clinic in Jackson. "It is a medical diagnostic modality that performs high-resolution, real time imaging of tissue measured in microns. It gives us a tomographic cross section of the retina and optic nerve."

Glaucoma, the second leading cause of blindness, is a group of eye conditions resulting in optic nerve damage and loss of vision. Abnormally high pressure inside your eye (intraocular pressure) usually, but not always, causes this damage. Glaucoma has two categories— open angle and closed angle.

Open angle is why glaucoma is called the "silent thief of sight," as there are no symptoms. Although it is the more common type, it can be caught only by examination.

Closed angle is uncommon, representing about 5 percent of glaucoma, but it is the type that usually causes a patient to seek medical treatment. With closed-angle glaucoma, the patient often experiences pain, halos around lights, redness and blurry eyesight.

"This form is also the reason why some medical labels caution not to take the drug if you have glaucoma," said Dr. Bateman. "Some medications, such as antihistamines, can dilate your eyes and precipitate a glaucoma attack. A glaucoma attack not treated in a timely fashion can lead to blindness. It is an urgent eye condition that can land a patient in the emergency room or eye doctor's office."

"We recommend that patients have their eyes checked every two to three years until age 65, then yearly, unless there is a history of eye disease," said Dr. Bateman. "Risk factors for glaucoma are elevated eye pressure, race because the disease is more prominent in African-Americans, diabetes, age, family history and high myopia, which is someone who is very nearsighted. These risk factors are typically discussed in an eye exam."

Visual field examination has historically been used in conjunction with clinical evaluation to diagnose glaucoma. In a regular visual field test, the visual field is mapped out as patients record what they see. "This makes the visual field test somewhat subjective in that we depend on the patient to tell us what they see," said Dr. Bateman. "The OCT is objective because it does not depend on patients to record what they see."
An OCT is used if the physician suspects disease after a clinical exam of the optic nerve and retina, said Dr. Bateman.

"The OCT is similar to an ultrasound, but it uses light instead of sound waves. The patients typically have their eyes dilated for the test in order to get an adequate evaluation. OCT measures a certain layer in the retina that makes up the optic nerve. Thinning in that nerve fiber layer would suggest glaucoma. The test gives an analysis of the severity of the thinning, or damage, which is used to determine how aggressive the treatment will need to be."

"Glaucoma is treated initially with drops to lower the intraocular pressure," he added. "When that is not effective, lasers can be used to treat the disease. The last resort is glaucoma surgery."

Regardless of the treatment, glaucoma has no cure, and once damage has occurred, it cannot be reversed. "With OCT technology," said Dr. Bateman, "we have improved our ability to diagnose glaucoma earlier in the disease process and hopefully slow its progression and minimize the long term damage. As the technology evolves into higher resolution, it will only get better."

Featured Doctor

Mark Bateman, M.D. Ophthalmology

Dr. Bateman, a native of Lexington, received his medical degree from East Tennessee State University. He served his internship at the Naval Hospital in San Diego and his residency at the National Naval Medical Center in Bethesda, Md. He is board certified in ophthalmology.