By Sola Ogundipe
Glaucoma is one of the leading causes of blindness in the world. It can occur at any age but is more common in older adults.
The most common form of glaucoma has no warning signs. The effect is so gradual that you may not notice a change in vision until the condition is at an advanced stage.
Vision loss due to glaucoma can’t be recovered. So it’s important to have regular eye examinations that include measurements of eye pressure. If glaucoma is recognised early, vision loss can be slowed or prevented. But those with the condition, generally need treatment for life.
According to an Associate Professor of Ophthalmology, Dr. Adeola Onakoya, glaucoma is the second leading cause of irreversible blindness worldwide and in Nigeria.
Onakoya, who is the Head, Glaucoma Services/HOD of Ophthalmology, College of Medicine/Lagos University Teaching Hospital, all Nigerians above the age of 30 should undergo regular screening for the common cause of blindness.
She said with ageing, the population of glaucoma sufferers will increase. Population studies in Nigeria revealed that 1.8 million people over 40 years suffer from glaucoma with almost 360,000 (20 per cent) of them blind in both eyes.
Poor awareness and late detection and in appropriate treatment contribute to high number of blindness cases. She warned that every Nigerian is at risk of the disease but higher in the population over 30 years.
Glaucoma is the result of damage to the optic nerve. As this nerve gradually deteriorates, blind spots develop in your visual field. For reasons that doctors don’t fully understand, this nerve damage is usually related to increased pressure in the eye.
Glaucoma tends to run in families. In some people, scientists have identified genes related to high eye pressure and optic nerve damage.
Open-angle glaucoma is the most common form. Pressure in the eye gradually increases. This pressure damages the optic nerve. It happens so slowly that you may lose vision before you’re even aware of a problem.
The signs and symptoms of glaucoma vary depending on the type and stage of the condition.
They include patchy blind spots in the side (peripheral) or central vision, frequently in both eyes as well as tunnel vision in the advanced stages.
For acute angle-closure glaucoma, there could be severe headache, eye pain, nausea and vomiting, blurred vision and eye redness. If left untreated, glaucoma will eventually cause blindness. Even with treatment, about 15 percent of people with glaucoma become blind in at least one eye within 20 years.
The doctor performs several tests, including measuring intraocular pressure (tonometry), testing for optic nerve damage, checking for areas of vision loss (visual field test) and measuring corneal thickness (pachymetry). Inspecting the drainage angle (gonioscopy) is also done.
The damage caused by glaucoma can’t be reversed. But treatment and regular checkups can help slow or prevent vision loss, especially in you catch the disease in its early stage.
The goal of glaucoma treatment is to lower pressure in the eye (intraocular pressure). Depending on your situation, your options may include eyedrops, laser treatment or surgery.
Glaucoma treatment often starts with prescription eyedrops. Other treatment options include laser therapy and various surgical procedures.
Promptly see an ophthalmologist if you experience the symptoms of acute angle-closure glaucoma, such as severe headache, eye pain and blurred vision.
Ophthalmologists recommend glaucoma screening every four years beginning at age 40 if you don’t have any glaucoma risk factors, and every two years if you’re at high risk or over 65.