This year World Sight Day is on Thursday 10 October. To raise awareness of this event, Porterhouse Medical Group is shining a light on some of the most common causes of avoidable blindness and how we can tackle this problem globally.
World Sight Day is held every year in October to raise awareness of blindness and vision impairment, and to highlight actions being taken to reduce preventable vision impairment. It is part of the Vision 2020 online global initiative to eliminate avoidable blindness and reduce the negative impacts of vision loss and impairment . The call to action of this year’s World Sight Day is ‘Vision First!’, with the aim of encouraging people to familiarise themselves with their country’s plans to tackle blindness, and to take an eye test and remind others to do so too.
Avoidable blindness is defined by the International Agency for the Prevention of Blindness as blindness or impairment that can either be prevented or treated by known, cost-effective means; nearly 75% of blindness globally is avoidable .
Avoidable blindness can be caused by a variety of different factors, such as poor nutrition and lack of education about eye health. In less developed countries, these problems are compounded by lack of access to resources and fewer skilled health practitioners to diagnose and treat problems. Some of the most common causes of avoidable blindness are outlined below .
The number of people living with diabetes has more than doubled since 1980 . Despite the rise of the sedentary lifestyle in high-income countries being a contributing factor to this dramatic increase, low- and middle-income countries account for approximately 75% of people afflicted with the disease . Diabetes increases the risk of many eye diseases, such as diabetic retinopathy (DR), diabetic macular oedema and glaucoma, but, of these diseases, DR is the main cause of blindness in people with diabetes. One in ten people living with this disease will develop a vision-threatening form of DR. It can be treated to prevent further vision loss, but vision cannot be restored and, if left unmanaged, can lead to blindness.
Fortunately, in the case of type 2 diabetes, appropriate lifestyle changes can contain the damaging effects of the disease, which can prevent vision loss.. However, in countries that are ill-equipped to deal with diabetes, it is often left undiagnosed and vision-saving lifestyle changes are not always possible .
A cataract is the clouding of the lens of the eye, preventing clear vision. Cataracts reduce vision in the affected eye, and if left untreated can lead to blindness. Almost half of all cases of blindness worldwide are a result of cataracts . There are several risk factors associated with cataracts, including diabetes, ultraviolet light exposure and smoking.
Despite being relatively easy to treat, many people globally remain blind as a result of cataracts because they lack access to treatment. The proportion of blindness due to cataract in developed countries is 5%, compared with 50% in poor or remote regions. As a result of cataract awareness programmes, cataract is now included in most national plans for the prevention of blindness, and surgical procedures for removing cataracts are becoming more accessible in many countries .
Vitamin A deficiency
Vitamin A deficiency (VAD) affects 190 million children under five globally and is a significant cause of childhood blindness and increased mortality. This problem is particularly prevalent in Africa and South-East Asia . Blindness associated with VAD can be prevented with only two doses of vitamin A given annually to children aged 6–59 months . As well as preventing blindness, these vitamin A supplements can significantly reduce the mortality of children under five in countries where VAD is a public health problem.
Currently, in order to tackle avoidable blindness, the World Health Organization (WHO) has created an action plan that aims to globally tackle avoidable blindness by increasing awareness of eye diseases and improving access to treatment. Over the last few years, the WHO has developed and implemented several tools for assessing the provision of eye care and rehabilitation services. The WHO is also developing a report that will offer recommendations for improving the provision of eye care globally .
1. The International Agency for the Prevention of Blindness. What is avoidable blindness. Available at: https://www.iapb.org/knowledge/what-is-avoidable-blindness/. Accessed October 2019.
2. World Health Organization. Global report on diabetes. Available at: https://apps.who.int/iris/bitstream/handle/10665/204871/9789241565257_eng.pdf?sequence=1. Accessed October 2019.
3. International Diabetes Federation. Executive summary. In: IDF Diabetes Atlas. 6th ed; 2013: pages 12–13.
4. The International Agency for the Prevention of Blindness. Diabetic retinopathy. Available at: https://www.iapb.org/knowledge/what-is-avoidable-blindness/diabetic-retinopathy/. Accessed October 2019.
5. The International Agency for the Prevention of Blindness. Cataract. Available at: https://www.iapb.org/knowledge/what-is-avoidable-blindness/cataract/. Accessed October 2019.
6. World Health Organization. Nutrition: Micronutrient deficiencies. Available at: https://www.who.int/nutrition/topics/vad/en/. Accessed October 2019.
7. The International Agency for the Prevention of Blindness. Vitamin A deficiency. Available at: https://www.iapb.org/knowledge/what-is-avoidable-blindness/vitamin-a-deficiency/. Accessed October 2019.
8. World Health Organization. Blindness and vision impairment: Key activities. Available at: https://www.who.int/blindness/key-activities/en/. Accessed October 2019.