By Evangeline T. Capuno
Aurelio didn’t think much was wrong when he woke up one Sunday morning with his right eye feeling sore, heavy, and itchy. It’ll get better once I wash my face, he thought while examining his reddish eye in the bathroom mirror. “I took it lightly because the pain and itchiness were still tolerable,” he admits.
Since he was already scheduled for a party with his family and friends that day, he still went along. While everyone was enjoying themselves, it was a different story for Aurelio: his vision suddenly became blurred in his right eye, and everything he looked at was foggy. The following day, he consulted a doctor and was then hospitalized for further examination. The diagnosis: glaucoma.
“I was totally shocked,” Aurelio said. “I never thought it would happen to me. More shocking is the fact that glaucoma is so widespread in the country.”
Glaucoma ranks as the third leading cause of blindness in the country. “Studies indicate that roughly 10% of the population over 40 years old will develop glaucoma,” said the website, glaucoma.ph. “This high prevalence signifies a critical health issue needing urgent attention.”
Unfortunately, half the people with glaucoma don’t know they have it because the condition usually destroys eyesight without warning and often without symptoms. “It’s a slow, gradual disease that often goes undetected,” says Dr. Manolette Roque, an ophthalmologist of the Roque Eye Clinic.
Understanding glaucoma
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.
At first, glaucoma damages peripheral vision. Over time, glaucoma may also damage central vision and result in blindness. Sight is lost slowly over many years. “Should there be some hints, the patient may still not know since there is a lack of general knowledge about the symptoms of glaucoma,” says Dr. Saw Seang Mei, associate professor of the department of community, occupational and family medicine at the National University of Singapore.
“Glaucoma is an important public health problem,” says Dr. Gerard Chuah, a consultant ophthalmologist at the Mt. Elizabeth Medical Centre in Singapore and author of A Patient’s Guide to Glaucoma and Glaucoma Treatment. “Blindness due to glaucoma is irreversible, unlike other eye diseases such as cataract where some amount of vision can still be restored after a successful surgery.”
Risk factors
Although advancing age is the biggest risk factor, glaucoma can strike anyone. “Family history of glaucoma, especially first degree relatives, is one of the major risk factors for developing glaucoma later in life,” says Dr. Liza Sharmini Ahmad Tajudin, a Malaysian lecturer of the ophthalmology department at the Universiti Sains Malaysia in Penang.
Smoking, extended use of steroids, extreme nearsightedness (myopia), and previous eye surgery also increase the risk of glaucoma. Ditto for diseases that affect blood flow to the optic nerve like diabetes, high blood pressure, and migraine. Sleep apnea, a sleep disorder that affects breathing and reduces oxygen thereby distressing the optic nerve, is another risk factor.
If you have two or more of the risks, you better have yourself screened for glaucoma by an ophthalmologist. Going for regular eye examinations is the best way to detect glaucoma early.
A glaucoma test usually includes an optic nerve check with an ophthalmoscope, eye pressure check or tonometry, and, if necessary, a visual field assessment that tests the sensitivity of side vision, which glaucoma strikes first.
“Early detection of glaucoma is important because it is a blinding disease,” says Dr. Maria Imelda Yap-Veloso, an ophthalmologist professor and a full-time consultant at the Asian Eye Institute in Makati City. “If glaucoma is diagnosed early, then the disease may be controlled and the visual complications from this disease may be prevented.”
Types of glaucoma
Actually, there are several types of glaucoma, including: open-angle glaucoma, closed-angle glaucoma, normal-tension glaucoma, and congenital glaucoma. The US-based Cleveland Clinic gives the following explanation of each:
Open-angle glaucoma: This type is the most common, affecting up to 90% of people who have glaucoma. It occurs when resistance builds up in your eye’s drainage canals. Your drainage canals appear to be open and functioning normally. Over months or years, the fluid in your eye can build up and put pressure on your optic nerve. The disease may go unnoticed for years because most people don’t have symptoms.
Closed-angle glaucoma: Also called angle-closure or narrow-angle glaucoma, this rare type often comes on suddenly (acute). It occurs when the angle between your iris and cornea is too narrow. It may happen when your pupil changes and becomes too big (dilated) too quickly. This blocks your drainage canals and prevents aqueous fluid from leaving your eye, causing eye pressure to rise. Symptoms, including eye pain and headaches, can be severe and require immediate medical attention.
Normal-tension glaucoma: As many as one in three people have optic nerve damage even when eye pressure is normal or not very high. Experts are uncertain about what causes normal-tension glaucoma. Another name for this type is normal-pressure or low-tension glaucoma.
Congenital glaucoma: Some babies are born with drainage canals that don’t form properly in the womb. Doctors might notice your baby’s glaucoma symptoms at birth or signs may become noticeable during childhood. Other names for this type are childhood, infantile or pediatric glaucoma.
“Most people develop glaucoma in both eyes, although the disease initially may be worse in one eye,” Cleveland Clinic said. “With open-angle glaucoma, one eye may have moderate or severe damage, while the other eye may be mildly affected. People with closed-angle glaucoma in one eye have a 40% to 80% chance of developing the same type of glaucoma in the other eye within five to 10 years.”
Treatments
“Depending on the type and stage of glaucoma it can be treated with eye drops, laser or surgery,” says the Philippine Glaucoma Society. “Since there is no cure, lifelong monitoring is needed.”
Among the more promising treatments for glaucoma are gene therapies designed to relieve fluid pressure that leads to optic nerve damage in the eye or to protect the nerve from such damage. Another potential therapy involves newly discovered natural molecules that act to regenerate nerve cell growth in the optic nerve, thereby promoting vision recovery.
Many new glaucoma drugs – with higher potency and lesser side effects – have been introduced recently. In Asia, the Singapore National Eye Center is involved in several clinical trials of these drugs. “Drug-coated contact lenses that release drugs over a period of time is one possible development in the near future,” says Dr. Steve Seah, senior consultant and head of the glaucoma service at the Singapore National Eye Center.
In the laser front, a newer laser that causes less destruction to the target tissue has already been launched. “The results have been promising,” Dr. Seah reports.
Still, early detection and treatment of glaucoma before it causes major vision loss. As Dr. Andrew Iwach, a glaucoma specialist and clinical spokesperson for the American Academy of Ophthalmology, told Medscape Medical News: “Glaucoma is a disease that has a slow onset, so you have to diagnose it as early as possible.” – ###
