What is the Most Common Eye Disease in Africa?
November 22, 2023
Africa, an expansive and diverse continent, exhibits distinct characteristics across its regions. Notably, the northern countries from Morocco to Egypt stand out in various aspects. Regarding health descriptions and planning, the World Health Organization (WHO) explicitly categorizes sub-Saharan Africa within the African region. Consistent with this classification, our paper will refer to Africa as synonymous with sub-Saharan Africa.
This region hosts around 7.1% of the world’s 38 million blind individuals, as the World Health Organization reported. The following sections will examine current data on blindness and eye diseases in this region.
6 Common Eye Diseases in Africa
As indicated by these surveys, approximately 50% of cases of blindness in Africa stem from cataracts. The prevalence of bilateral cataracts leading to blindness in Africa is around 0.5%. However, this statistic is influenced by the regional frequency of cataract surgeries. Unfortunately, there is a lack of reliable information regarding the occurrence of cataracts among Africans. While studies have explored race as a risk factor for cataracts in the United States and the Caribbean, it may be inappropriate to extrapolate these findings to Africa due to significant differences in other risk factors, particularly diabetes, among the populations. Similar to trends observed elsewhere, females exhibit slightly higher rates of cataract incidence, the underlying reasons for which are not fully understood. The primary focus in the context of cataracts lies in advancing service delivery.
Although trachoma has been declining in many areas of the world, it remains the second leading cause of blindness in Africa. An estimated 2.2 million individuals in Africa have blindness attributed to trachoma. Trachoma exists throughout much of sub-Saharan Africa. In some areas, there is inadequate information to estimate the disease burden. The investigations have shown that women account for about 75% of all trachomatous trichiasis and subsequent blindness due to corneal scarring. Although the prevalence of active trachoma is similar among boys and girls, adult women tend to exhibit higher rates of active disease, likely due to their more frequent interactions with children. In certain areas, trachoma reaches a holoendemic status, where every child experiences active trachoma and every adult displays signs of conjunctival scarring. At any given time, rates of active disease in children can soar as high as 50%.
There have been numerous anecdotal accounts highlighting elevated rates of open-angle glaucoma (OAG) among Africans, with an onset typically occurring at a younger age compared to white populations. Reports reveal a lack of awareness about glaucoma among most affected people, and at least 50% of the cases present with blindness. Two population-based studies employing stringent definitions have provided valuable insights. The first, conducted in the Western Cape of South Africa, reported an OAG prevalence of 1.5%, alongside a primary angle closure glaucoma prevalence of 2.3%. The second study, conducted in Tanzania, indicated an OAG prevalence of 3.1% among people aged 40 and above. This rate is comparable to the prevalence observed in African Americans and individuals of African origin in the Caribbean. In the Tanzanian population, OAG accounted for 5% of all cases of blindness, while the prevalence of angle closure glaucoma was 0.6%, aligning with rates found among African Americans.
- Diabetic Retinopathy
There is substantial evidence indicating the occurrence of diabetic retinopathy among Africans with diabetes who seek medical care in urban centers across the continent. The prevalence of various types of retinopathy within clinic populations studied ranges from approximately 15% to 50%. It can be inferred that overall diabetes care in Africa is suboptimal, with limited access to retinopathy treatment for most diabetics. The improvement of general diabetes care and increased life expectancy may lead to a higher incidence of blindness resulting from diabetic retinopathy in the future.
Onchocerciasis, commonly known as river blindness, remains prevalent in 30 African countries and is likely responsible for approximately 99% of the estimated 270,000 cases of blindness attributed to onchocerciasis globally. The distribution of onchocerciasis is highly localized, mainly confined to the region extending from Senegal in the west to Ethiopia in the east and southward to Malawi. The occurrence of blinding onchocerciasis is predominantly concentrated in West Africa. In contrast, many areas in Eastern Africa where onchocerciasis is endemic show minimal or no cases of blindness associated with the infection.
- Refractive Errors
The most common eye issues in Africa are refractive errors, encompassing conditions such as myopia (near-sightedness), hyperopia (farsightedness), astigmatism (distorted vision at all distances), and presbyopia, which typically manifests between the ages of 40 and 50 (resulting in a diminished ability to focus up close, difficulty reading small print, and the necessity to hold reading material farther away). These issues can be rectified through eyeglasses, contact lenses, or, in certain instances, surgical interventions.
Having good eyesight is crucial for navigating the world around you. Some vision issues are easily rectified, while others may lack a cure. Nonetheless, early detection and intervention can often correct or slow the progression of many eye diseases, minimizing potential vision loss. If you observe any alterations in your vision, it is advisable to consult with your eye care professional. Regular eye clinic check-ins are essential, even without noticeable changes, as some vision problems may not exhibit early warning signs. Your eye doctor can conduct necessary tests, prescribe eyewear or medications, and, if required, perform surgery to mitigate or prevent vision loss to get optimal vision clarity.