UAB Medicine News
What You Should Know About Glaucoma
Despite advances in treating glaucoma, there is no cure, and any lost vision cannot be restored. However, early detection, diagnosis, and treatment can help preserve vision.
A leading cause of blindness in the United States, glaucoma occurs when the fluid pressure inside the eyes rises and damages the optic nerve, though that pressure is not always the cause of the damage. In many cases, the fluid in the eye, known as the aqueous humor, doesn’t circulate normally in the front of the eye, thereby creating pressure that affects the eye in the same way too much air may cause a balloon to swell beyond its limits. Rather than bursting, however, the eye relaxes at the weakest point, where the optic nerve leaves the eye. Then the optic nerve, which carries visual information to the brain, becomes damaged due to the death of the retinal cells and degeneration of nerve fibers. Without treatment, glaucoma slowly leads to the loss of peripheral (side) vision and possibly all vision.
Other causes of glaucoma include a blunt or chemical eye injury, severe eye infection, inflammatory conditions of the eye, and blockage of blood vessels in the eye.
Glaucoma currently affects some 2.7 million Americans, according to the National Eye Institute, but that number is expected to double by 2050 due to an aging population.
Detection and Diagnosis
According to Kayla Thomason, OD, at UAB Callahan Eye Hospital Clinic at Pell City, glaucoma is “silent” in its initial stages, so regular screenings are the best way to prevent or reduce vision loss.
“Patients are normally symptomless at first, so they don’t have any reason to suspect that anything is wrong with their eyes,” Dr. Thomason says. “Early symptoms may present as missing vision, but tunnel vision doesn’t happen until advanced stages. So in order for us to detect risk factors, yearly dilated eye exams are extremely important. Detection and diagnosis really are the main defense against glaucoma, especially for patients over age 40.”
The exam can locate such risk factors as high pressure, thin corneas, and thinning around the optic nerve. The development of glaucoma depends on the level of pressure an individual’s optic nerve can tolerate without suffering damage. That level varies for each person. A comprehensive dilated eye exam enables eye care professionals to determine what level of eye pressure is normal for each patient.
“Sometimes we can detect this by examining their optic nerves,” Dr. Thomason says. “It’s a disease of asymmetry, so for patients with cupping (an unusually large section in the optic nerve) that’s different in one eye compared to the other, even if it’s not particularly significant cupping, the difference may be an indicator. Then we’ll go further and check fields of vision with a visual field machine. We’ll check for any thinning around the optic nerve with optical coherence tomography (OCT), a non-invasive imaging test, and measure their corneal thickness. Thin corneas can put you at risk, too.”
Who’s at Risk?
Everyone should be concerned about glaucoma and its effects, but there are certain factors related to this disease that tend to put some people at greater risk:
- Aging is the No. 1 risk factor. Everyone age 40 and up should have a comprehensive eye examination every 1.5 to two years. Those 40 or older with any of the additional risk factors listed below should have an eye exam annually.
- Family history of glaucoma. Glaucoma appears to run in families. While a predisposition for glaucoma may be inherited, having a family member with glaucoma does not indicate you will develop the condition.
- Abnormally high intraocular pressure (IOP). High IOP is the most significant risk factor for glaucoma damage.
- African, Latino, or Asian ancestry. People of African, Latino, and Asian descent have a greater risk of developing certain types of glaucoma.
- Medical history of diabetes, myopia (nearsightedness), long-term steroid/cortisone use, a previous eye injury, or extremely high or low blood pressure.
None of these factors are precise predictors of future health conditions, but research does suggest that glaucoma risk factors can serve as reliable guidelines. Everyone under age 40 should have a comprehensive eye examination every 3-4 years. Individuals under 40 with at least one of the above risk factors above should get tested every 18 months to two years, and those who are at least 35 with multiple risk factors should be tested every year or two.
The UAB Callahan Eye Hospital Clinic at Pell City provides the high-quality vision care and advanced treatments for which Callahan Eye Hospital is known, now with convenient and timely access in your area. Along with comprehensive ophthalmology and optometry services for adult and pediatric patients, this clinic features an in-house optical store offering a wide selection of designer eyeglasses and sunglasses. Click here to schedule an appointment.