Glaucoma, a group of eye conditions that damage the optic nerve, essential for good vision, is one of the leading causes of irreversible blindness in Africa affecting more than 6 million people.
Shockingly only 1 in 20 are aware they have glaucoma and 50% will be blind in one eye by the time they seek an ophthalmologist for the first time.
In Sub-Saharan Africa, it is estimated that 4.16% of the population aged 40 years and older are affected by glaucoma with a higher incidence among the black population (5-7%) compared to the Caucasian population (3-5%).
Despite being treatable, the South African Glaucoma Society (SAGS) emphasises the major challenges faced, including lack of awareness, late diagnosis, poor follow-up visits, and low compliance with treatment plans.
Dr Marissa Willemse, specialist Ophthalmologist and President of SAGS highlights that glaucoma, often termed the "silent thief of sight," exhibits no noticeable symptoms in its early stages, underscoring the critical importance of awareness.
"Vision loss has devastating social, personal and economic impact, often leading to unemployment, loss of income, lowered standards of living, depression and anxiety. Early detection of glaucoma is essential to improve the chances of preventing vision loss and blindness."
"Untreated glaucoma increases intraocular pressure - the pressure, or force, that builds up inside of your eyes - damaging the optic nerve, which is responsible for transmitting visual information from the eye to the brain. Over time the optic nerve damages lead to vision loss and in advanced stages, blindness which cannot be restored."
She said that access to eye care services, including screening, diagnosis, and treatment for glaucoma, is essential for managing the condition effectively. "In South Africa, efforts are being made to improve access to eye care services, particularly in underserved communities where the burden of glaucoma may be higher."
Who is most at risk?Dr Willemse says that there are certain risk factors for developing glaucoma and that regular eye examinations with an ophthalmologist are crucial in detecting glaucoma early, as the condition often does not cause noticeable symptoms until it has already caused vision loss.
The risk factors include:- Age: The risk of developing glaucoma increases with age, particularly in individuals over 60 years old although in Africa the age is as recent as 40.
- Family history: A family history of glaucoma, especially in a first-degree relative (parent or sibling).
- Race or ethnicity: African Americans, Africans, Hispanics, and Asians are at a higher risk.
- High intraocular pressure: Individuals with elevated intraocular pressure (IOP) are at a greater risk of developing glaucoma. However, not everyone with high IOP will develop glaucoma, and some individuals with normal IOP may still develop the condition.
- Thin central corneal thickness: Studies have shown that individuals with thinner corneas may be at a higher risk.
- Medical conditions: Certain medical conditions, such as diabetes, hypertension, and cardiovascular disease, can increase the risk.
- Previous eye injuries or surgeries: Trauma to the eye or previous eye surgeries.
- Near-sightedness: increases the risk of developing glaucoma.
With progression over time, certain warning signs will appear which should not be ignored. Dr Willemse says "Its important to note that some of these symptoms can also be caused by other eye conditions, necessitating a thorough eye examination to find the root cause and decide on the appropriate treatment options."
- Gradual loss of peripheral vision: Glaucoma often affects peripheral vision first, leading to tunnel vision or more often blind spots in the side or corners of the visual field. Patients are often only diagnosed after failing their drivers license renewal test.
- Blurred vision: Blurry or hazy vision can indicate damage to the optic nerve.
- Halos around lights: Some glaucoma patients may experience halos or glare around lights, especially at night.
- Eye pain or redness: In a few cases eye pain, redness, or discomfort can be detected.
- Nausea or vomiting: Severe cases of acute angle-closure glaucoma can cause symptoms such as nausea, vomiting, and severe eye pain. This is an emergency, and a patient can lose his or her vision within hours of the onset of the angle closure.
It is recommended that any under the age of 40 years undergo screening every 2-4 years, between 40 and 60 years of age every 2-3 years, and over 60, yearly.
Screening for glaucoma typically involves a comprehensive eye exam that includes several tests to assess the health of the eye and detect any signs of glaucoma, including:
- Tonometry: Measuring the pressure inside the eye (intraocular pressure) using a tonometer device. Elevated intraocular pressure is a key risk factor for glaucoma.
- Ophthalmoscopy: An ophthalmologist examines the optic nerve at the back of the eye for signs of damage or abnormalities associated with glaucoma.
- Perimetry (visual field test): This test measures the vision in the peripheral areas to detect any blind spots or areas of reduced vision that may show damage to the optic nerve.
- Gonioscopy: An ophthalmologist examines the drainage angle of the eye to determine if it is open or closed, which can help diagnose certain types of glaucoma.
- Special investigations such as Optical Coherence Tomography: the optic nerve and nerve fiber layers can be monitored for early changes and progression of glaucoma.
"Once the screening has been completed the ophthalmologist will establish an individual treatment plan for each patient with glaucoma," Dr Willemse explains. "It is essential that the patient adheres to the plan and attends regular follow-up appointments to monitor their eye health and ensure that the condition is well-managed. We cannot stress enough how early detection and treatment of glaucoma is essential for preserving vision and preventing vision loss."
She said the main aim of treatment is to lower the intraocular pressure and prevent further damage to the optic nerve. This can be done with medication such as Citicoline which is used to help protect the optic nerve from oxidative stress and damage.
Eye drops are often prescribed to lower intraocular pressure in glaucoma and can be used chronically to prevent the build-up of pressure. Laser therapy may be used to improve the drainage of fluid from the eye and lower intraocular pressure. In some cases where medications and laser therapy are not effective, surgical procedures may be recommended.
Dr Willemse underscores the importance of awareness, urging regular eye exams, early detection, and appropriate treatment for effective glaucoma management. Accessing support networks and resources is essential for those living with glaucoma and their families in navigating treatment and care.