Tunnel Vision

MANILA, Philippines - If you find yourself literally looking at life with a narrower point of view, or viewing a vista as if through a fog, you should go and schedule an appointment with your ophthalmologist. Chances are you are among the growing number of Filipinos who have glaucoma, an eye condition where there is damage to the optic nerve which connects the eye to the brain, causing the visual field to shrink.

The Philippine Glaucoma Society recently revealed that glaucoma is the country's leading cause of bilateral irreversible blindness. It is a health issue that Filipinos should be aware of, says Ma. Imelda Yap-Veloso, the current president of the Philippine Glaucoma Society, especially because early detection is key to saving sight. Even without experiencing any symptoms, a regular screening test by an ophthalmologist once you hit your 40s is advisable, she adds.

According to Veloso, there are two common types of this condition: Primary open-angle and angle-closure glaucoma, and they both have a link to eye pressure. She emphasizes that the right doctor to consult would be an ophthalmologist, and not an optometrist, because the tests that they administer at mall optical shops rarely take intraocular pressure (IOC) into account. She explains that the eyeballs need internal pressure to retain its globular shape and the ability to see. But when something interferes with the ability of the eye's internal structures to regulate this pressure, the pressure pushes against the optic nerve until the nerve fibers are damaged. In one type of glaucoma, the aqueous humor (a liquid which brings nutrients to the eye tissues, aside from helping the eyeball maintain the aforementioned globular shape) may not flow freely into a drainage canal, and this causes the pressure to build up. That is why a high IOC is a glaucoma indicator.

Veloso enumerates some of the symptoms as a gradual loss of peripheral vision for primary open-angle types; and severe eye pain, nausea and vomiting (accompanying the eye pain), sudden onset of blurred vision, halos around lights, and eye redness for acute angle closure glaucoma.

She lists the risk factors for this condition:

• Age. "People who are 45 and above should have an eye exam," she says.

• Family history.

• Injury to the eye.

• Nearsightedness or farsightedness.

• Steroid use. "A study has found that patients with prolonged high dosage of steroids, such as those used for treating asthma are at risk," she explains.

• Eye drop use. Over-the-counter eye drops that are used to banish red eyes have vasoconstrictors that affect high pressure. Dr. Yap-Veloso says that even though these eye drops are quite easy to purchase without a prescription, one should always use them under the guidance of a physician.

• Diabetes. Experts have found that people with diabetes are twice as likely to develop glaucoma as are non-diabetics, and conversely, the likelihood of someone with open-angle glaucoma developing diabetes is higher than that of a person without the eye disease. "Those with diabetes are also at risk for developing neovascular glaucoma," the doctor says. This condition happens when new blood vessels grow on the iris and block the fluid flow in the eye, therefore raising the eye pressure.

No turning back

The bad news is that there is no treatment for glaucoma that can bring the eyesight back to normal. The best that doctors can do is to stop it from further developing. There are several treatment options available depending on the type of condition.

The first line of defense is the use of eyedrops. These are used to lower the intraocular pressure, by either reducing the production of the aqueous fluid or increasing the drainage of the fluid from the eye. Laser therapy is another option. Here, a microlaser is used to make a hole in the angle of the eye to allow for better drainage. Surgery may also be performed on a patient, where an artificial exit for fluids is inserted, or a thin part of the sclera or eye wall is removed. Surgery is often the last option used because it can have complications such as infections or bleeding.

The fact that glaucoma is irreversible means that it is crucial to catch it at early onset. That is why the Glaucoma Society of the Philippines, and its health-care partner Allergan, have conducted a series of information campaigns about this condition. This campaign aims to raise public awareness of this health issue, and help patients fully understand the choices available to them and make well-informed treatment decisions with their doctors.