Look after your eyesight

THIS week is World Glaucoma Week and healthcare workers globally commit to raising awareness and demystifying this condition, often referred to as a silent thief of sight.

Indeed it creeps in like a thief and snatches sight away, silently and painlessly.

Glaucoma is one of the leading causes of irreversible blindness in the world.

The typical scenario eye specialists encounter on countless occasions is of a puzzled and agitated adult who walks into their consulting room, bumping into desks and objects but able to see where he or she is headed, because peripheral vision has been lost.

The patient gives a typical history of a slowly progressive, painless visual deterioration that has been ignored or casually managed with reading glasses.

Ultimately, he or she noticed that when crossing a busy intersection he or she was unable to see cars appearing from either side.

Patients with glaucoma lose their peripheral vision first, then much later their central vision.

Glaucoma leads to irreversible blindness and often with no warning signs such as pain, except for the type referred to as acute angle glaucoma.

Glaucoma can affect one eye but the common type of glaucoma called open angle glaucoma affects both eyes and the speed of progression of the disease might not be the same in the two eyes.

This will then result in one eye becoming blind while the other eye still has good vision.

Another common scenario is that of a patient coming to consult an ophthalmologist for treatment of a minor ailment, like dry eyes.

On examination the specialist then incidentally discovers that glaucoma is the problem.

There are a large number of individuals who only discover they have poor vision when they go to the traffic department for their traffic licences.

Literature states that glaucoma affects up to 2% of individuals over the age of 40 globally and up to 10% over the age of 80. Up to 50% may be undiagnosed and don't even know that they have the disease

Primary open angle glaucoma is common and aggressive in people of African descent. This form of glaucoma is also prevalent among diabetics, myopic individuals (short-sighted) and patients with diseases of the heart and blood vessels.

It can also be hereditary. This means that we should all invest some time in studying the disease profiles in our families and take appropriate action: having our eyes checked regularly.

Glaucoma can also arise as a complication of, or in association with, many other conditions such as blunt injuries to eyes, inflammations, infections and tumours of the eye.

Glaucoma results in damage to the optic nerve and gives characteristic visual field defects due to a high intra-ocular pressure.

Glaucoma has some similarities with high blood pressure and diabetes in its nature. They all are conditions that are controllable but not curable.

They run in families and if left unattended result in end organ damage.

If discovered early, glaucoma can be treated and visual loss can be halted or significantly slowed down.

Treatment compliance is of utmost importance in averting blindness.

The best thing you can do for yourself is to have your eyes checked annually by an ophthalmologist or an optometrist if you are at high risk of developing glaucoma, and every two years if you have a low risk.

The second best thing you can do is to encourage your loved ones, friends and colleagues to have their eyes checked regularly.

• Makunyane is the acting dean of the department of ophthalmology at the University of Pretoria