Bjorn Thylefors MD
Director, Programme for the Prevention of Blindness and Deafness
World Health Organization
CH-1211 Geneva 27
Switzerland Despite considerable efforts in many developing countries, through national blindness prevention programmes, the global number of blind and visually disabled seems to be growing, mainly as an effect of population increase and ageing. Thus, the most recent (1997) projected estimate for world blindness points to some 45 million blind, and an additional 135 million visually disabled (‘low vision’). About 80% of blindness is avoidable (preventable or curable), and nine out of 10 of the world’s blind live in a developing country.
Given this alarming situation, with a potential doubling of the world’s blindness burden by 2020, a series of consultations were held during 1996 and 1997, between the WHO Programme and the Task Force to the Partnership Committee of collaborating Non-Governmental Organisations, with a view to developing a common agenda for global action against avoidable blindness; the expected result would be a strengthened and accelerated movement for blindness prevention, particularly in the developing world.
The Global Initiative for the Elimination of Avoidable Blindness, as a result of the consultations held, is focusing on a few priority disorders, and on what action needs to be taken from now to the year 2020, in terms of (i) disease control; (ii) human resource development; and (iii) infrastructure strengthening and appropriate technology development for eye care delivery.
Operations/Million Population/Per Year
Cataract stands out as the first priority amongst the major causes of blindness, with an estimated present backlog of 16-20 million unoperated cases. The number of cataract operations/million population/per year is a useful measure of the delivery of eye care in different settings; this demonstrates great differences, as shown:
Thus, there is a need to increase drastically the number of cataract surgeries in the developing world; the present estimate is that approximately 7 million operations were performed globally in 1995, and there will be a need to perform 12 million surgeries in the year 2000, to prevent a further growth of the backlog. Similarly, by the year 2010, 20 million operations should be done, and in 2020, an impressive 32 million cataract operations will be needed. At the same time as numbers go up, there should also be a change in technology with intraocular lens implantation as a common standard, and the proper follow-up of quality of surgery. This will call for better management and monitoring of services, including patient satisfaction.
Trachoma is still the most common cause of preventable blindness in the world, with some 5.6 million blind, and around 146 million cases of active disease in need of treatment. A suitable strategy, referred to as ‘SAFE’ (Surgery, Antibiotics, Facial Cleanliness and Environmental Hygiene) has been defined, and is being increasingly applied in endemic countries. A recently established (1997) WHO Alliance for the Global Elimination of Trachoma will facilitate collaboration with all interested parties, including 46 endemic countries with blinding trachoma. Actions envisaged under the Global Initiative include the provision of around 5 million trichiasis operations, from the year 2000 to 2010, and treating at least 60 million people with active disease in the same period. By the year 2020, global elimination of blindness due to trachoma should be achieved.
Onchocerciasis will be brought under control by the year 2010 if ongoing operations in endemic countries are successfully completed. The recent development of community-directed treatment with annual doses of ivermectin will make it possible to eliminate this burden of blinding disease from the countries affected in Africa and Latin America.
Childhood blindness is caused mainly by vitamin A deficiency, measles, conjunctivitis in the newborn, congenital cataract and retinopathy of prematurity. There is rapid progress in eliminating xerophthalmia and measles, as part of ‘child survival’ initiatives, supported by several UN and other organisations. However, much more work is needed to detect, at an early stage, the other causes of childhood blindness and to manage them optimally.
Refractive errors and low vision constitute another priority in terms of visual disability; there is an enormous need globally for spectacles and low vision devices. The Global Initiative will focus on refractive services as part of primary health care and school services, and local low-cost production of glasses and optical devices will be promoted.
Human Resource Development
In the field of human resource development emphasis will be on the primary health care approach to blindness prevention. This implies continuing support for primary eye care training in countries. In addition, there will be strengthened efforts to train more ophthalmologists, from the present situation of one ophthalmologist per 500,000 people in Africa, to achieve 1:250,000 by the year 2020. The corresponding figures for Asia would be from 1:200,000 today, to 1:50,000 in 2020. Similarly, increased training of ophthalmic medical assistants and ophthalmic nurses should result in a ratio of 1:100,000 or 1:50,000 in the year 2020, as compared to 1:400,000 today in Africa and 1:200,000 in Asia respectively. It is also envisaged that there should be 100% coverage of training in basic eye care in medical schools by the year 2020. Other categories of staff to be trained under the Global Initiative include refractionists, managers for national/regional programmes and for major clinics, and also equipment technicians.