Norma Connolly
norma@cfp.ky

Glaucoma is the second leading cause of blindness in the world, with the so-called “silent thief of sight” affecting up to 70 million people.

The disease earned its nickname because it can sneak up on people as there are no obvious early symptoms to warn sufferers.

Cayman Islands-based optometrist Dr. Elaine Campbell explains that the major risk factors for glaucoma are a family history of the disease, people older than 40, those of African descent and people with very high prescriptions. Myopia, or nearsightedness, is measured in diopters by the strength or optical power of a corrective lens a prescription of -6.00 or more is considered high.

While the disease can creep up gradually, “if a person has an acute attack, they know about it. They have pain beyond belief and their vision gets cloudy because the pressure has shot up to a very high level,” says Cambpell.

“If that happens, it has to be treated immediately. You have to bring the pressure down or the optic nerve cells will die,” she adds. “The problem with glaucoma is that patients often don’t know they have it. By the time they come and say ‘I can’t see anymore’, it’s too late to do anything.”

The leading cause of blindness is cataracts, which according to the World Health Organisation is responsible for 47.9 per cent of blindness cases, while glaucoma is responsible for 12.3 per cent of vision loss.

Glaucoma damages the eye’s optic nerve, which carries images to the brain. That damage cannot be repaired and can lead to blind spots. If left untreated, those blind spots spread, leading to tunnel vision and eventual total loss of sight.

Treatment - either with eye drops or surgery - cannot reverse the damage already done to a person’s sight, but can halt further loss of vision.

Those at risk for glaucoma should make regular visits to an ophthalmologist for tests on eye pressure, cornea thickness or the optic nerve. Different tests are necessary as high eye pressure, while it is a symptom of glaucoma, can be present in people without glaucoma and people with glaucoma do not always have high eye pressure, Campbell explains.

In most types of glaucoma, the eye’s drainage system becomes clogged, so the intraocular fluid cannot drain. Intraocular fluid is the clear fluid at the front part of the eye which normally flows out through the pupil and in the bloodstream. As the fluid backs up, it causes pressure to build up within the eye. The high pressure damages the sensitive optic nerve and results in vision loss.

Eye drops and surgery clear that blockage, effectively “fixing the plumbing”, says Campbell.

According to the Glaucoma Research Foundation in the United States, people with high risk factors should be tested every year or two after age 35; those younger than 40 should be tested every two to four years; from age 40 to age 54, every one to three years; from age 55 to 64, every one to two years; and after age 65, every six to 12 months.