Glaucoma! stop silent thief of vision

• Has No Cure But Can Be Managed — Experts

To mark World Glaucoma Week, medical experts have advised Nigerians to go for regular eye test, as early detection is key to reducing the advancement of glaucoma and symptomless glaucoma. They also said a late stage glaucoma is irreversible and it results in loss of sight and blindness, if not properly treated.

A consultant ophthalmologist and Head of Department, Ophthalmology, General Hospital, Lagos Island and The Ocular Centre, Lekki, Dr. Adebimpe Adebajo, explained that the theme for this year’s Glaucoma Week is BIG-Beat Invisible glaucoma. “This is because glaucoma is invisible,” she said. “Glaucoma is an optic nerve disease. It is not just one disease, but a group of diseases that has no known cause and cure. It causes gradual damage to the optic nerve, which results in vision loss and eventually blindness, and is irreversible.

“Glaucoma is called the ‘Silent thief of vision’ because of its slow onset and progression, causing permanent vision loss with very few signs if at all. The disease can be classified into primary or secondary. The primary is congenital or acquired. The commonest type is the primary form, which could also be open angle or closed angle. They all cause blindness, if not diagnosed and treated well. And though there are no known causes, but there are several risk factors. These include intraocular pressure (IOP). Glaucoma is frequently caused by a buildup of pressure inside the eye. But the disease can still occur when the IOP is in the normal range.”

Adebajo said the black man has a more aggressive and worse type of glaucoma compared to a Caucasian, and that family history could contribute to an individual developing the disease. She said: “There is a strong genetic or familial trait, which means it is hereditary. That’s why it is important to know one’s family medical history. However, anybody is at risk of developing glaucoma. Indeed, these days, we are seeing very young patients in their early teens developing glaucoma, which is scary. It could also be linked to medical history (diabetes and hypertension). The incidence is higher if you are above 40 years.

“Glaucoma is usually an incidental finding. Most patients don’t come in and say ‘Doctor, I have glaucoma.’ They usually come for something else. That is why it’s such a sinister condition, because it gives no sign or warning. It’s invisible, and that is why we have to create the awareness and encourage everyone to have his/her eyes checked. Ideally, Eye MS (multiple sclerosis) should be checked at birth, pre-primary school about five years. Afterwards, it should be done at pre-secondary school, at about 10 to 11 years and then 16 years. After that, the person is an adult and should initially have checkups every five years, unless there is a problem.

“But once you turn 40, you should have a full ophthalmic check and then yearly. Usually at 40 years, people tend to develop several ailments, such as diabetes and hypertension, all of which increase the risk of glaucoma. If a parent has glaucoma, then there is 25 percent chance of children developing the disease. And if that parent is blind from glaucoma, that increases the risk to 50 percent.”

So, what kind of food should someone who is already diagnosed avoid?
She said: “Glaucoma has nothing to do with food. Even the healthiest person can have it. In fact, there is no particular food to be avoided. Ordinarily, the older one gets, the healthier the diet should be. Then, what should be consumed are more vegetables, less carbohydrates, oily fishes and chicken or turkey and less red meat. There should also be lots of pulses and legumes.

“The treatment of Glaucoma is usually done with drugs and/or surgery. However, it must be understood that every treatment modality does not cure glaucoma, it only reduces the rate of progression to blindness. It is not a one-size-fits-all treatment. Everybody’s treatment is tailored to that person. Granted some drugs are common, but they don’t work for everyone. Glaucoma is only managed. So, every glaucoma patient is a patient for life, and should be seen by his/her consultant every three to six months for the rest of their lives. The treatment also involves certain tests initially done biennially, such as CVFT and OCT (Optical Coherence Tomography), and can then be reduced to yearly.

“Prevention has to start by creating awareness. I can confidently say every ophthalmologist treats every other patient like a glaucoma patient. They counsel them and educate them. This education has to be continuous. The Ophthalmological Society of Nigeria has a great task ahead, but it cannot be done alone. We have optometrists and ophthalmic nurses to make up the Eye Team, but treatment cannot or rather, should not be commenced without an ophthalmologist intervention.

“Our policy makers should ensure that eye screening is mandatory and is part of school curriculum. It is a necessity. Also, a National Health Insurance scheme should be available and accessible to the common man. Hopefully, all these measures will reduce the incidence of unnecessary blindness in Nigeria and Sub-Saharan Africa and the world at large.”

On whether there are gender-based risk factors for glaucoma, Dr. Aribaba Olufisayo Temitayo, Senior Lecturer/Consultant Ophthalmologist, Department of Ophthalmology, College of Medicine University of Lagos and Lagos University Teaching Hospital, said there is none. He said: “I’m not sure of any gender-based risk factor for glaucoma, except perhaps in relation to the health-seeking attitude of individual patients, and the control of family income mainly by men, leading to probable delay in presentation at the hospital earlier than the blindness threshold of the disease by women.

“Ordinarily, normal intraocular pressure is between 10 and 21mmHg. The intraocular pressure (eye pressure) measurement in isolation of the Central Cornea Thickness (measured with Pachymetres) correction may be misleading with thin cornea giving abnormally lower values and thick cornea higher values of intraocular pressures, respectively. The corrected intraocular pressure values are, therefore, more useful for glaucomatologists for obvious reasons.”

So, what is considered good eye pressure to maintain, if on medications for glaucoma?
He said: “It is recommended that the pressures should be in the lower tens, that is, 10 to15 mmHg, because of the diurnal variations and pressure spikes at night in some individuals. The treatment, which is medical, laser or surgical has the sole aim of reducing the intraocular pressure to reduce nerve fibre damage. Medical therapy is usually in preparation for laser or surgery and can be complimentary to both in achieving the individual patient’s “target pressure.”

On lifestyle changes to adopt, he advised glaucoma patients to co-operate with their eye health care team – glaucomatologist / ophthalmologist. He said: “The co-operation may be lifelong. There must be regular visits to the Ophthalmologist for evaluation and follow up, as well as good compliance and adherence to medications. Patients should ensure that all first degree relatives and offspring are screened regularly for glaucoma because it’s a genetic disease.

“There is need for prompt presentation with noticeable reduced vision attributable to other systemic illnesses, such as diabetes mellitus, hypertension and high cholesterol, among others, as well as cataract, age related macular degeneration, eye vascular disorders and diabetic eye diseases, among others.”