Health & Fitness

Silent eye disease that causes loss of sight

World Glaucoma Week
Mombasa residents during the World Glaucoma Week last March. PHOTO | LABAN WALLOGA | NMG 

Glaucoma is a silent but chronic disease that can lead to complete loss of sight.

In simpler terms, it is an eye pressure disease that progresses to catastrophic levels if not stopped in its tracks.

While it has no cure, the disease tends to be inherited and may not show up until later in life, usually past the age of 40.

The increased intraocular pressure (IOP) can damage the optic nerve, which transmits images to the brain.

Although everybody is at risk of getting glaucoma, there are certain groups of people who are at a higher risk of contracting the disease.


These include those with history of glaucoma in the family, adults aged over 40, African race, high IOP, myopia (shortsightedness) and diabetes mellitus.

The first sign of glaucoma is often a loss or peripheral or side vision. This can go unnoticed until the disease is at an advanced stage.

Icare Finland Oy representative Kasperi Kankare says the best way to tackle glaucoma is early detection through a medical diagnosis.

“Tonometry, the diagnostic test that measures IOP, can help your doctor determine whether or not you may be at risk of glaucoma,” he said.

It is the increased pressure in the eye that plays a role in the damage of the optic nerve. The damage caused is usually irreversible.

Upon positive diagnosis, patients can be put on pressure lowering eyedrops, oral medications, laser treatment, surgery or a combination of any of these.

Once glaucoma is diagnosed and treatment started, the follow-up with an ophthalmologist is lifelong.

Without treatment, that pressure can eventually harm the optic nerve, causing a loss of vision.

The equipment used to detect IOP is called a tonometer and has evolved since it was first developed in 1865 by German scientist Albrecht von Graefe.

However, it’s not until the late 19th century that the first reasonably accurate instrument was developed.

Goldmann’s applanation tonometer of 1950 began the era of truly accurate intraocular pressure measurement.

The latest improvement of the tonometer is by Icare Finland Oy, a company founded in 1996. Dubbed ICare TAO1, the equipment does not require disinfection or for patients to be under anaesthesia.

“The Icare tonometer’s disposable probe touches the cornea very lightly for only a fraction of a second, thus avoiding discomfort for patients,” says Mr Kankare.

ICare has partnered with Optical Supplies Africa to donate tonometers to University of Nairobi, Masinde Muliro University and Kenya Medical Training College for purposes of learning.

World Health Organisation 2010 data shows that one person out of 20 people aged above 40 in Africa has glaucoma.

The data shows that operated cataract and glaucoma are the leading causes of avoidable blindness.