Text by Henrylito D. Tacio
Photo credit: Arztsamui/Shutterstock
“Glaucoma is the leading cause of irreversible blindness in the world,” wrote Dr. Andrew A. Dahl in an article which was published in medicine.net. “While anyone can get glaucoma, some people are at greater risk.”
Worldwide, glaucoma is the second-leading cause of irreversible blindness. In fact, as many as 6 million individuals are blind in both eyes from this disease. In the Philippines, glaucoma is the second leading cause of blindness — after cataracts.
Generally, those who are affected with glaucoma are adults above 40 years old. “As the population increases and ages, the risk for glaucoma becomes higher,” points out Dr. Maria Imelda Yap-Veloso, an ophthalmologist at the Asian Eye Institute.
Like a thief in the night, glaucoma robs you of your vision without you knowing it. “Glaucoma can damage your vision so gradually you may not notice any loss of vision until the disease is at an advanced stage,” the Mayo Clinic says.
“Glaucoma is not just one eye disease, but a group of eye conditions resulting in optic nerve damage, which may cause loss of vision,” the Mayo Clinic points out. “Abnormally high pressure inside your eye (intraocular pressure) usually, but not always, causes this damage.”
Glaucoma develops when the production of liquid in the eye (called aqueous humor) increases or the liquid is not drained adequately. The pressure rises in the eye to unhealthy levels. Nerve fibers and blood vessels in the optic nerve – which carries visual impulses from the eye to the brain – become compressed and can be damaged or destroyed.
Glaucoma usually causes no symptoms early in its course, at which time it can only be diagnosed by regular eye examinations (screenings with the frequency of examination based on age and the presence of other risk factors).
Actually, there are two forms of glaucoma: acute and chronic. If you feel sudden eye pain, it may be a signal that you have an acute form that can lead to blindness. Acute glaucoma can occur when the drainage canal from the eyeball is suddenly closed off, and the fluid pressure builds rapidly, says Dr. Kevin Greenidge, a member of the glaucoma service at the New York Eye and Ear Infirmary.
Along with intense pain, you may have blurred vision and see rainbow halos around lights. Some people also experience nausea and vomiting. This condition may be relieved promptly, but you must get to a hospital as soon as possible.
Acute glaucoma is an ocular emergency. “If not treated immediately, acute glaucoma results in complete and permanent blindness within two to five days,” says Dr. Tony Ho, an eye surgeon with the Clearvision Eye Clinic in Singapore.
Although most common among people who are farsighted, acute glaucoma is rare. About 90 percent of those with the problem suffer from chronic glaucoma. This happens when the drainage canals in the eyes are blocked gradually slowly. Symptoms include teary, aching eyes, blurred vision, occasional headaches, and progressive loss of sight.
Glaucoma is an irreversible disease. As Dr. Mark De Leon, an ophthalmologist at the Cardinal Santos Medical Center puts it: “Glaucoma is a progressive disease and cannot be cured. Progression, however, can be delayed by proper treatment and follow-up.”
Early detection is the best way to combat glaucoma. The American Academy of Ophthalmology recommends a comprehensive eye exam for all adults starting at age 40 and every three to five years after that if you don’t have any glaucoma risk factors. If you have other risk factors or you’re older than age 60, you should be screened every one to two years.
Only an eye exam by an ophthalmologist can tell whether you have early glaucoma. But you should be alert to any changes in vision such as blurriness or “blanked-out” sights, says Dr. George Spaeth, professor of ophthalmology at Jefferson Medical College of Thomas Jefferson University. He’s developed this self-test to help you spot warning signs between eye exams:
Sit about a footway from a large television set tuned to a channel that has nothing but random, blurred spots or lines. Close your left eye and look at the center of the screen with your right eye. Are any areas of the screen blanked out, washed out, or less visible? Pay particular attention to the upper left-hand side of the screen: If you have trouble seeing that area, your vision loss may be caused by glaucoma. Reverse the procedure to test your left eye; look at the upper right-hand side of the screen to determine whether you’ve lost any vision in that eye. If this quick test shows any sight loss, don’t wait for your next regular eye exam. See an ophthalmologist right away.
Generally, medicines – in the form of eye drops – are the first line of treatment against chronic glaucoma. Oftentimes, doctors prescribe beta-blocker eye drops to lower liquid production in the eye. However, glaucoma can’t be controlled by just one bottle of medication alone; it is a lifetime problem, and eye drops will be the patient’s partner for the rest of his or her life.
For some people, eye drops may not be enough. In such cases, the doctor may prescribe oral tablets or intravenous injections. “Whether taken orally or injected, the drugs do not cure the disease but only reduce the ocular pressure and its fluctuations,” explains Dr. Liza Sharmini Ahmad Tajudin, a lecturer of the ophthalmology department at the Universiti Sains Malaysia in Penang.
There are several reasons why a person suffers from glaucoma. Among the so-called “glaucoma suspects” are advancing age, family history, steroid use, history of eye trauma, nearsightedness, diabetes, and hypertension. As such, eye doctors urge people to protect their vision. In addition, they must see their doctor regularly.
“Just like cancer,” reminds Dr. Yap-Velosos, “glaucoma is never cured. However, it can be controlled. The key management is early detection and treatment to preserve your vision.”