The silent thief of sight: Early detection can prevent blindness from Glaucoma

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Editor’s Note: Glaucoma is the leading cause of irreversible blindness in the world, with the highest number affected in Sub-Saharan Africa. This week (March 12 – 18, 2017) is World Glaucoma Week, and this year’s theme is BIG; Beat Invisible Glaucoma. Our Thought Leadership Series Piece this week is by Consultant Opthamologist Fatima Kyari. She explains the danger of the silent and gradual blindness caused by glaucoma, and lays out ways in which we can all help improve awareness and services for glaucoma prevention and care. Kyari is the Co-Chair for the International Agency for the Prevention of Blindness (IAPB), West Africa.

In Nigeria, one out of every 20 people above the age of 40 will be affected by glaucoma in their lifetime. Glaucoma is an eye disease that affects the optic nerve which is at the back of the eye. It is the leading cause of irreversible blindness, and happens when the pressure in the eyeball (intraocular pressure (IOP)) is too high for the normal functioning of the nerve. This disrupts the nourishment of the eye and the optic nerve, killing the cells and leaving fewer nerve fibres to transmit the information of vision from the eye to the brain.

Glaucoma causes gradual loss of vision in one eye before the other. One out of every five people who have glaucoma are blind in both eyes, and by the time they seek care in a hospital, about half of glaucoma sufferers are already blind in one eye. About 5 per cent of affected people are aware that they have the disease in its early stages. In total, one in every 100 people are affected with this silent disease.

75 year-old MA had lost vision in the right eye before he was diagnosed with glaucoma. He had trabeculectomy in the left eye 12 years ago and this has preserved his vision in that eye. Skilful trabeculectomy is one of the surgical treatments of choice in glaucoma. A patent drainage bleb is seen here. Cataract formation is a likely long-term effect.
Photo credit: Fatima Kyari

The silent and gradual nature of the disease is especially worrisome for a population where routine medical check-ups are not the norm, as highlighted by these stories from patients:

“Glaucoma… it is a silent thief of sight – I cannot say precisely when it started. When I was driving I would be seeing through the windscreen very well. I didn’t feel any pain. I didn’t know it was going to be a serious problem.” B.M. – 56 years old, civil servant.

“I wanted to shave my right underarm. I could not see it… but I was seeing my left underarm. That was when I discovered I was having an eye problem….so after about a month or so, I went to the hospital. And the doctor said I have glaucoma.” M.C. – 29 years old, salesman.

Vision lost due to glaucoma cannot be regained with treatment. As a result it is critical that people at risk of glaucoma have their eyes examined for early detection and offered treatment to prevent further loss of sight. People at a higher risk of glaucoma include those over 40 years old, people with a high IOP (eye pressure), men, and siblings or children of patients with glaucoma.

Vision loss from glaucoma has devastating consequences on people’s lives and results in reduced quality of life and loss of economic and social productivity in those affected and their families. The threat of vision loss also triggers anxiety to patients and some attach a morbid fear to it:

“I had a breakdown. A shock went through my spine. I even repeated the question to the doctor, “What do you mean by it is not reversible?” It affected me for up to one week, even if I sleep in the night, I will be like, ah ah! What kind of suffering is this that I will go blind? If it affects the other eye, I am gone. I have many dreams to get ahead in life; this is a distraction.” M.C. – 29 years old, salesman.

“Some people have told their families that they are going back to their ancestors [i.e. die] rather than living in blindness and, like magic, the following evening you find that that old Baba is dead! Eh? So if you ask me about the danger, I think it is more dangerous than death because some people prefer to die instead of living with blindness.” B.M. – 56 years old- civil servant, male.

Stereoscopic examination of the optic nerve is key to the diagnosis of glaucoma. The optic disc will be seen as “cupped” in glaucoma.
Photo credits: Gabriel Entekume

Recent advances in early diagnosis and appropriate life-long treatment can delay vision loss and can prevent blindness from glaucoma. These have already decreased the likelihood of vision loss from glaucoma in industrialised countries. However, in Nigeria, as in most countries in Sub-Saharan Africa, there is a high prevalence of blindness from glaucoma. This is because people with glaucoma seek care late, and when they do, treatment options are not always available, and there is poor compliance with available treatment.

When it started, we didn’t get money to come to the hospital. Three years ago, we went to the General Hospital. We followed the process…, but we didn’t have enough money. That is why we waited until this year again. That is why we are here now. The doctor said I have lost vision in my right eye.” 60-year old farmer.

“I went to (the hospital in) Zaria, between 1995 and 1996. The medicines were very expensive but I kept buying them. I kept going and returning home and in the end when I went, I didn’t have the money to buy the medicine so I gave up. So the condition aggravated and I went blind.” 52 year-old Imam.

It is critical to improve glaucoma care services in Nigeria

An important first step towards achieving this is institutional strengthening through better training of eye care teams for surgical skills and care, and making medicines and equipment available in tertiary and secondary centres for optimal glaucoma care, thereby increasing clinical treatment options.

There are three potential treatment options all aimed at lowering the eye pressure of the glaucoma patient:

  1. Medical treatment – a life-long use of eye drops, the most effective being prostaglandin analogues (e.g. latanoprost) and beta-blockers (e.g. timolol).
  2. Surgical – the commonest being trabeculectomy, which creates a channel for drainage of aqueous to reduce the pressure within the eye.
  3. Laser treatment – works by either reducing the production of aqueous or by increasing the drainage channel of aqueous to lower the pressure within the eye.
Diode laser micropulse trabeculoplasty is a form of laser treatment for glaucoma. Photo credits: Adunola Ogunro

Other complimentary strategies towards improving glaucoma care services in Nigeria are financing glaucoma care so that no-one is left untreated because he/she cannot afford it; introducing approaches to earlier detection; and strengthening health systems governance and developing policies to include glaucoma care in national healthcare plans with inclusion of eye health especially cataract and glaucoma care in programmes for non-communicable diseases.

Rather than remaining silent, let us give patients with glaucoma a voice so that the invisible thief of sight does not lead them into darkness. We can ‘Beat Invisible Glaucoma” together!

Read more about Dr.Kyari’s work here, here and here.

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