The World Glaucoma Week: What is it?
This is a week that has been set aside by the World Glaucoma Association (WGA) and World Glaucoma Patients Association (WGPA) to create awareness about Glaucoma and encourage eye-screening and early detection. This year, the week comes off from March 7-13.
What is Glaucoma?
This is a group of eye diseases that destroys the optic nerve connecting the eyeball to the brain. The optic nerves transmit all the information we see with our eyes to the brain, where they are interpreted. The optic nerve is part of the central nervous system, and once it is damaged it cannot be repaired – thus making Glaucoma the leading cause of irreversible blindness worldwide.
How big is the Glaucoma situation in Ghana?
Glaucoma affects more than 700,000 people in Ghana. Population-based surveys show that approximately 7.7% out of Ghanaians aged 30 years and above, and 8.5% of those aged 40 years and above, have Glaucoma (Ref. Akwapim South Survey). Though more recent figures from the Tema Eye Survey point to lesser figures, they still make Ghana one of the most-affected countries in the world.
Hospital-based studies in North Eastern Ghana show that more than half (52%) of all glaucoma patients present blind in at least one eye at the time of diagnosis, while more than one-third (34%) present blind in both eyes. These figures are only slightly worse than those in the cities.
According to the Ghana Blindness Survey published in 2017, Glaucoma accounts for almost 20% of all causes of blindness in the country and is the number-one cause of Irreversible (Permanent) Blindness in Ghana.
What causes Glaucoma?
The exact cause of glaucoma is not completely understood. However, there are certain factors that increase our risk of getting glaucoma. These include high fluid pressures in the eye, having a family member with glaucoma, being of African decent, having medical conditions such as diabetes, high blood pressures, sickle-cell and other diseases of our circulatory system.
Other common causes of glaucoma in Ghana include eye injuries and indiscriminate use of eye-drops containing steroids. The final common pathway in most cases is increased pressures in the eye with damage to the optic nerve.
How is Glaucoma Diagnosed?
Glaucoma is generally a disease without symptoms, especially in the early stages. This is why its Akan name is “Hintanifraye”, (a disease that hides and blinds you) as proposed by Dr. Opoku of Agogo Hospital is very appropriate. Its complete diagnosis is usually made by highly trained eye specialists, using special equipment and physical examination involving the front and back parts of the eye. Your specialist would usually assess how much damage there is to the eye and how much is this damage affecting your sight. He would also measure the pressures in your eyes and establish what type of glaucoma you have.
Do we have different types of Glaucoma?
Yes. There are two major types. One in which the water (aqueous humour) from the front chamber of the eye is able to enter its drainage system but does not drain out as well as we would expect (Open Angle Glaucoma) and a second type in which the entrance to the drainage system is either too narrow or blocked altogether (Angle Closure Glaucoma) making it difficult for the water to enter the drainage channels and drain away.
In each case, the eye pressures go up and the optic nerve gets damaged. The first type, which is by far the most common in Ghana, is generally silent and progresses slowly. Each of them has sub-divisions and note also that children may be born with Glaucoma at birth (Congenital Glaucoma). Note also that there are types of glaucoma in which the eye pressures are normal and yet there is significant and progressive damage to the optic nerve.
This variant is called Normal Tension Glaucoma. Conversely, there are a few patients who have high pressures in their eyes but there is no damage. This condition is called Ocular Hypertension and such cases need regular follow up as many of them eventually would end up with nerve damage and thus become glaucoma cases.
Why should we worry about Glaucoma?
Unlike most other diseases, Glaucoma generally has no symptoms, at least in the early stages and can only be detected through an eye screening. In the late stages however, when it has caused significant damage to the optic nerves you may notice loss of your peripheral (side) vision. Depending on the extent of loss of side vision, you might bump into doors when entering, you may have difficulties seeing cars coming from your side views and thus at risk of causing road traffic accidents. As the disease progresses, side vision progressively constricts making you walk as if seeing though a tunnel and thus its name “Tunnel Vision”. Eventually your central vision reduces and finally blinds out completely.
Image 2: Progressive Loss of Vision in Glaucoma
Management of Glaucoma:
Glaucoma diagnosis and management requires a highly skilled training. This is especially so in differentiating the various types and formulating effective treatment plan that takes into consideration, treatment effects on other body systems. Though the disease can be treated to prevent blindness, it cannot be cured. Treatment may be medical or surgical or both. Surgical treatment may also involve Laser surgeries. Your ophthalmologist will discuss the various options available to you and you will both decide which treatment option is most suitable for your case.
Economic burden of Glaucoma care on the Ghanaian patient
The last time, we computed the overall cost of caring for glaucoma over a period of 20 years was in 2013. Our model took into account average use of 3 anti-glaucoma medications, monthly hospital visit to check eye pressures, average year-on-year inflation of 10% among other variables. A total cost of between US$60,000 to US$65,000 dollars was arrived at for each patient. This is an amount that should be able to build a retirement home for each of these patients.
On the other hand, this cost burden can effectively be mitigated if highly effective glaucoma drugs like prostaglandin analogues and those in other classes like alpha-agonists and eye drops made from ACE-inhibitors can be covered by the NHIS. This may however first involve making the drugs available in the National Essential Drugs List and this has been articulated in a previous speech during launch of the World Glaucoma Week at the Ministry of Health Conference Hall.
Conclusion
Glaucoma is a silent disease that steals your sight. It has no cure but early detection enables us to initiate appropriate treatment to save you from going blind. Do well to get your eye screened for Glaucoma, during the World Glaucoma Week.
>>>The writer is a Glaucoma/Retina Specialist and President of the Ophthalmological Society of Ghana
