A typical scenario I encounter on countless occasions is that of puzzled and agitated adults who walk into my consulting room, bumping into desks and objects because they have lost their peripheral vision but are able to see where they are headed. They would give a typical history of a slowly progressive, painless visual deterioration that they have ignored or casually managed with reading glasses. Ultimately, they noticed that when crossing a busy intersection, they are 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 does so without warning signs such as pain, except for the type referred to as acute angle-closure glaucoma.

Another common scenario is of a young adult who, by chance, notices that their one eye is blind whilst casually covering the other eye. 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 may not be the same in both eyes. This will then result in one eye becoming blind, whilst 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 the patient has glaucoma.

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

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. Fifty per cent 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 (short-sighted) individuals, and patients with other diseases of the heart and blood vessels.

It can also be hereditary. This means that we should all invest some time into studying the disease profiles of our biological families and take appropriate action – have our eyes checked regularly.

Primary closed-angle glaucoma has a high prevalence in individuals of Far-Eastern descent.

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

Summarily, I would say glaucoma results in damage to the optic nerve and gives characteristic visual field defects due to a high intraocular pressure.

An attempt to explain or describe what actually happens to the eye affected by glaucoma is rather difficult without the use of visual aids such as pictures or models of the eye. I therefore urge readers to consult ophthalmologists and/or optometrists for screening for this disease and to ask relevant questions regarding glaucoma.

Glaucoma has some similarities to high blood pressure and diabetes in its nature. They are all conditions that are controllable, but not curable. They run in families and if left untreated, they result in irreversible end-organ damage.

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

Glaucoma treatment can be either medical, with the use of eye drops and/or tablets, or surgical. After a careful assessment, treatment options will be determined by the treating ophthalmologist. 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 a 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 too.

Socio-economic implications of irreversible blindness are enormous, negatively impacting family units, standard of living and the economy as a whole. Blindness naturally leads to psychosocial issues such as depression and anxiety due to loss of independence, unemployment and neglect by family and friends.

Finally, I would like to remind all the eye healthcare workers to check their own eyes and their family members’ for glaucoma. We tend to neglect ourselves as we take care of our patients.

Dr Seipati Makunyane is the Acting Head of Department: Ophthalmology at the University of Pretoria.