Read why ‘More Nigerians are being diagnosed with glaucoma

With the World Glaucoma Week which ended on Saturday, Dr. Chigozie Onyesonwu, an expert optometrist, tells MOTUNRAYO ABODERIN that Glaucoma is a silent eye killer disease that requires urgent attention

What is glaucoma?


Glaucoma is a slowly progressive cause of vision loss, usually associated with an elevated pressure in the eye. Loss of side vision generally occurs prior to loss of reading or driving vision. There are different types of glaucoma, all of which are associated with damage to the optic nerve, which is usually but not always related to high eye pressure. However, high eye pressure is not always a sign that you have glaucoma but may be an indication you are at risk of developing it.

How does it develop?

There is a constant flow of fluid through the eye. This fluid is called aqueous humour. It is secreted into the eye from an area behind the iris and flows around through the pupil and drains out of the eye through several microscopic channels. Glaucoma usually develops when this flow of fluid becomes obstructed and there is a build-up of pressure within the eye.

Is it a disease that has visible symptoms?

The biggest problem with glaucoma is the lack of symptoms, since you can’t feel the pressure in the eye. If it is at its advanced stage, its symptoms may be visible. One common symptom is poor vision. So the patient would frequently have to open his or her eyes wide in order to see. But even if the person opens his or her eyes wide, the vision would still be blurred.

Only a few people get headaches, red eye, or blurred vision. If you don’t get your eyes tested regularly, the first noticeable symptom could be permanent “holes” in your vision. Lack of treatment of glaucoma often leads to blindness.

Which age bracket is likely to be affected?

In the past, people thought the disease was only common with the aged, but that is no more the case. Family members who have had frequent cases of Glaucoma should endeavour to go for regular checkups once they are approaching 40. However, if you are between the age of 20 and 64 years, you should have your eyes checked every one or two years. From the age of 65 years onwards, you should have them checked every year. But if you have any of these risk factors, you should go as often as your eye care professional recommends.

Would it be right to say the disease has become rampant in Nigeria?

Yes. Increasingly, studies show that some people are at greater risk for glaucoma than others and that glaucoma also manifests itself differently in various ethnic groups. Also, the cases of persons who are being diagnosed with glaucoma on a monthly basis is on the increase in Nigeria. We also have high prevalence in temperate regions more than regions dominated with whites. Studies have shown that glaucoma is about four times more common in Africans than in people of European ancestry.

Can you shed more light on the causes of the disease?

The exact cause of primary open-angle glaucoma is unknown. A number of conditions, alone or in combination, are needed to trigger the processes leading to increased pressure and then to the nerve damage that destroys sight. The damage done to the optic nerve in glaucoma is triggered in most cases by the excessive pressure on the optic nerve that, over time, causes damage. Because optic nerve damage occurs in patients with normal as well as high intraocular pressure, however, there are other factors that occur and can damage the optic nerve.

In addition, people with acute closed-angle glaucoma often have a structural defect that causes a narrow angle between the iris and cornea where the aqueous humor circulates. Conditions that suddenly dilate the pupils may cause this shallow angle to close and precipitate attacks of acute glaucoma in susceptible people.

How can glaucoma be prevented?

Currently, regular eye exams are the best form of prevention against significant glaucoma damage. However, people who have already been diagnosed with glaucoma would have to manage the situation either through surgery or drugs. Anyone with high risk factors should be tested every year or two after age 35. Those at higher risk include people of African descent, people with diabetes, and people with a family history of glaucoma. You are at increased risk if you have a parent or brother or sister with glaucoma

Can we put a time frame to the point at which Glaucoma manifests?

When a patient begins to notice blurred vision, he or she should take action. Open-angle glaucoma is dangerous because it doesn’t give warnings before leading to blindness.

Does it have a cure?

There is no cure for glaucoma yet, except through surgery. Aside surgery, the patient can be placed on medication to manage the condition. The drugs would be taken throughout his or her life time.