Childhood Blindness

Childhood Blindness

As the causes of blindness in children differ from those in adults, different control measures are needed. In low-income countries, high proportions of children are blind from preventable causes, which require community-based interventions. In all regions, children with treatable diseases, principally cataract, can have their sight restored. Childrens’ eyes cannot, however, be considered smaller versions of adults’ eyes, and specific expertise and equipment are required. Unlike adults, children require longterm follow-up after surgery, to manage complications and to prevent amblyopia (‘lazy eyes’). The understanding and involvement of parents is critical. In all regions, children with irreversible visual loss must be assessed for low-vision services, early visual stimulation, rehabilitation or special education, depending on their age and level of residual vision.

Current situation

It has been estimated that there are 1.4 million blind children in the world, 1 million of whom live in Asia and 300 000 in Africa (26). The prevalence ranges from 0.3/1000 children aged 0–15 years in affluent countries to 1.5/1000 children in very poor communities. Although the number of blind children is relatively low, they have a lifetime of blindness ahead, with an estimated 75 million blind-years (number blind × length of life), second only to cataract.
The same report showed that 500 000 children become blind each year (nearly one per minute). Many die in childhood from the underlying cause, such as measles, meningitis, RUBELLA , prematurity, genetic diseases and head injuries. Most blind children are either born blind or become blind before their fifth birthday. Owing to demographic differences, the number of children who are blind per 10 million population varies from approximately 600 in affl uent countries to approximately 6000 in very poor communities. About 40% of the causes of childhood blindness are preventable or treatable.


The causes of childhood blindness vary, but the main avoidable causes are:

corneal scarring in Africa and poorer countries in Asia;
cataract everywhere
glaucoma everywhere;
retinopathy of prematurity in high- and middle-income countries and some cities in Asia;
refractive errors everywhere, but particularly in South-East Asia; and
low vision, which encompasses visual impairment and blindness from untreatable causes, in all regions.
The main causes of blindness in children change over time. As a consequence of child survival programmes (for example, integrated management of childhood illness), corneal scarring due to measles and vitamin A defi ciency is declining in many developing countries, so that the proportion due to cataract is increasing. Retinopathy of prematurity is emerging as an important cause in the middle-income countries of Latin America and eastern Europe and is likely to become an important cause in Asia over the next decade. The prevalence of refractive errors, particularly myopia, is increasing in school-age children, especially in South-East Asia

Achievements
Vitamin A deficiency: There are concerted global efforts to control vitamin A deficiency in children and women of child-bearing age. The United Nations Children’s Fund (UNICEF) has estimated (27) that between 1998 and 2000 about 1 million child deaths were prevented by these global efforts, and the Vitamin A Global Initiative led by UNICEF has set the target of eliminating vitamin A deficiency by the year 2010.
Measles: Measles immunization coverage continues to improve, resulting in a lower incidence of measles and measles-related deaths. In 2004, there were 454 000 deaths from measles, a reduction of 48% from 1999. The Measles Initiative (28), a partnership between the American Red Cross, the United States Centers for Disease Control and Prevention, the United Nations Foundation, UNICEF and WHO, is now focusing on 47 countries, mainly in sub-Saharan Africa where 98% of deaths occur, with the goal of reducing deaths from measles by 90% by 2010 from the estimates for 2000. The WHO Region of the Americas has eliminated measles, and three other regions have set elimination targets. Reducing the prevalence of measles will also reduce the number of children with measles-related corneal ulceration and scarring.
Retinopathy of prematurity: Programmes for detecting and treating severe retinopathy in premature infants at risk are expanding throughout Latin America and eastern Europe and are being established in urban areas in China, India and other Asian countries.
Child eye-care centres: Training in paediatric ophthalmology is becoming more prevalent, and tertiary level child eye-care centres are being set up in low-income countries.
Consumables for children: Low-vision devices suitable for children as well as other consumables are available through resource centres in Hong Kong, China, and Durban, South Africa.
Limitations
inadequate population-based data on the prevalence and causes of blindness in children;
lack of awareness among parents and the community about preventive measures and that the vision of children who are blind can often be improved or maximized;
barriers to accessing services, including lack of awareness, distance, cost, fear and competing demands for scarce resources within the family;
shortage of paediatric eye-care professionals and inadequate opportunities for training in paediatric ophthalmology in most low-income countries;
lack of international exchanges in human resource development for paediatric ophthalmology and insufficiently developed postgraduate curricula for training paediatric ophthalmologists in many industrialized countries;
fragmentation of paediatric eye-care services in many countries, so that children who need specialist expertise are managed by general ophthalmologists; and
inadequate provision of special education for children with irreversible visual loss, particularly in low-income countries.
Aim
to eliminate avoidable causes of blindness in children
Objectives
to promote programmes that reduce corneal scarring and visual loss from vitamin A deficiency and measles and
to implement interventions against harmful traditional practices, neonatal conjunctivitis and eye injuries;
to provide services to treat children with cataract, glaucoma, retinopathy of prematurity and corneal ulcer or scarring;
to provide optical services for children with refractive errors, for instance in school eye-health programmes; and to provide services for children with low vision.
Strategies
Provide comprehensive services for children at all levels of service delivery'
In areas where childhood blindness from preventable diseases is common, increase awareness in the community and encourage primary health care, including specific preventive measures at the primary level, through primary eye care, including:

measles immunization, to prevent corneal scarring;
vitamin A supplementation, nutrition education, food supplementation and fortification of commonly eaten foods with vitamin A, to control vitamin A deficiency;
avoidance of harmful traditional practices, to prevent corneal scarring; ocular prophylaxis of newborns, to prevent neonatal conjunctivitis; and
rubella immunization where congenital rubella is an important cause of mortality or morbidity in children, with strategies appropriate to the setting (e.g. schoolgirls aged 12–13 years).
At the secondary level, strengthen diagnosis and management of less complex cases.
At the tertiary level, provide specialist training and services for the management of surgically remediable visual loss from cataract, congenital glaucoma and corneal scarring, including longterm follow up. Examine premature infants at risk of retinopathy of prematurity, treat those with severe disease and promote oxygen monitoring.
As children with cataract often do not present, or present late, undertake active case finding, particularly for girls.
Provide each child eye-care centre with a well-trained team (e.g. paediatric or child-centred ophthalmologist, optometrist, anaesthetist, counsellor, low-vision therapist, mid-level personnel), appropriate equipment and infrastructure and access to consumables for infants and children (e.g. small spectacle frames, high-power intraocular lenses).
Ensure the availability of ophthalmologists experienced in indirect ophthalmoscopy to identify premature infants in intensive neonatal care who require treatment for retinopathy of prematurity.
Ensure that infants at risk have fundus examinations starting 4–6 weeks after birth and that infants with severe disease are treated immediately by laser or cryotherapy.
Develop low-vision services for children with irreversible visual loss at secondary and tertiary levels.
Promote school eye-health programmes:
for the diagnosis and management of common conditions, such as refractive errors, and trachoma and vitamin A deficiency in endemic areas;
to promote a healthy environment; and
to educate children in looking after their eyes as part of the normal school curriculum.
In areas where significant uncorrected refractive errors affect more than 2% of schoolchildren aged 11–15 years (29).
Ensure that children undergo a simple vision screening examination, ideally as part of the school health programme, with provision of spectacles to those who will benefit.
Ensure that all children in special education establishments are examined by an ophthalmologist and receive medical, surgical, optical or low-vision services to maximize their vision.
Ensure good linkages between eye-care services and those providing education and rehabilitation services for incurably blind children.
Targets
By 2011, each country’s national plan will include the control of blindness in children, with achievable targets.
For disease control:
reduction in the global prevalence of blindness in children from 0.75/1000 to 0.4/1000 by the year 2020;
reduction in corneal scarring caused by vitamin A deficiency, measles, neonatal conjunctivitis and the use of traditional eye remedies;
reduction in the proportion of blindness due to retinopathy of prematurity, particularly in countries where it is responsible for more than 10% of blindness in children; and appropriate management of children with cataract, with immediate, effective optical correction in suitably equipped specialist centres.
For human resource development:
prevention of blindness in children an explicit aim of primary health care programmes and included in all primary eye-care training curricula
personnel in secondary-level eye clinics with knowledge and skills necessary to manage less complex eye conditions in children; and
at least one child eye-care centre with a well-trained team for every 20 million population by the year 2011 and one per 10 million by 2020.
For infrastructure and technology
all child eye-care centres have adequate supplies of consumables for children, e.g. paediatric aphakic spectacles and low-power, small-diameter intraocular lenses; and
secondary-level eye clinics have facilities to provide appropriate spectacles for children with refractive errors.
Indicators
prevalence of childhood blindness;
prevalence of avoidable childhood blindness, by cause
number of child eye-care centres per at least 20 million population (recommended);
from other WHO programmes:
proportion of countries with measles immunization coverage > 80%;
proportion of countries with vitamin A deficiency control programmes or with eliminated vitamin A deficiency, in line with global targets; and
proportion of countries with a policy or immunization programme for rubella.
Trachoma

Trachoma, which is the commonest infectious cause of blindness, is caused by Chlamydia trachomatis. Children who have the active stages of the disease are the reservoir of infection, while blindness, which occurs after repeated episodes of infection, principally affects adults. Boys and girls are equally affected by active infection, while blindness is more common in women. Trachoma is a condition of poverty and is a focal disease, affecting communities that have poor water supplies and sanitation and poor health services. The organism is transmitted from person to person through direct and indirect contact and by flies. Blindness can be prevented by surgery to correct inturning of the upper lid (trichiasis),
while the infection and its transmission can be reduced with surgery, antibiotics, facial cleanliness and environmental change (the SAFE strategy).

Current situation
Trachoma is endemic in 55 countries: Afghanistan, Algeria, Australia, Benin, Brazil, Burkina Faso, Cambodia, Cameroon, Central African Republic, Chad, China, Côte d’Ivoire, Djibouti, Egypt, Eritrea, Ethiopia, Fiji, Gambia, Ghana, Guatemala, Guinea, Guinea-Bissau, India, Islamic Republic of Iran, Iraq, Kenya, Kiribati, Lao People’s Democratic Republic, Libyan Arab Jamahiriya, Malawi, Mali, Mauritania, Mexico, Morocco, Mozambique, Myanmar, Namibia, Nepal, Niger, Nigeria, Oman, Pakistan, Papua New Guinea, Senegal, Solomon Islands, Somalia, Sudan, Togo, Uganda, United Republic of Tanzania, Vanuatu, Vietnam, Yemen, Zambia and Zimbabwe. The estimated number of affected people has fallen from 360 million in 1985 to about 80 million today. Trachoma affects the poorest and most remote rural areas of Africa, Asia, Central and South America, Australia and the Middle East (30). Updated reports on 36 countries are available (31), while 19 endemic countries have not yet reported data.


There are approximately 10.6 million people with inturned eyelashes (entropion trichiasis), for which eyelid surgery is needed to prevent blindness. The majority of these people are women. An estimated 5.9 million adults are irreversibly visually impaired from corneal scarring due to trachoma.

Achievements

At national level, political support for trachoma control has increased continually since 1997, the year the WHO Alliance for the Global Elimination of Blinding Trachoma (GET 2020) was created; intersector collaboration is growing, and use of the SAFE strategy for eliminating the disease is increasing.


GET 2020 is active at the global level. It is a public–private partnership, bringing together WHO, national coordinators, nongovernmental organizations, donors and international experts, with support from the pharmaceutical industry. Launched in 1997, it was endorsed by WHA Resolution 51.11, adopted in 1998. A nongovernmental organization task force, the International Coalition for Trachoma Control, has been working since 2004 within the framework of GET 2020 to improve information exchange with governments and to coordinate the efforts of international nongovernmental organizations in countries. The GET 2020 secretariat is responsible for trachoma within the WHO department focusing on neglected tropical diseases. The WHO GET 2020 secretariat is also coordinating the drawing up of guidelines for certification of elimination of blinding trachoma, as requested by several WHO Member States.

Limitations
Not all countries in which blinding trachoma is suspected to be endemic have undertaken a proper assessment of the epidemiological situation of trachoma.
The WHO SAFE strategy does not yet cover 100% of the populations in trachoma-endemiccountries.
International partners who are members of the WHO GET 2020 Alliance do not implement the entire SAFE strategy, but only certain components.
The available resources for trachoma control are not suffi cient to achieve the ultimate intervention goals in all countries.

Aim
Global elimination of blindness due to trachoma by the year 2020 by applying the WHO-recommended SAFE strategy
Objectives
Integrate the SAFE strategy into primary health care in all communities with blinding trachoma.
Certify the elimination of trachoma in countries, where applicable.
Strategies
Identify districts where blinding trachoma is a public health problem
Provide surgical services with trained and certifi ed medical or paramedical staff at community level to operate on cases of trachomatous trichiasis.
Provide mass antibiotic administration (azithromycin or tetracycline ointment) for populations living in districts where the prevalence of active disease (follicular trachoma) in children aged 1–9 years is above 10%. In districts where the prevalence is below 10% but above 5%, community or family treatment might be required. The treatment interventions must be implemented in association with promotion of personal hygiene, with particular focus on facial cleanliness of children under 10 and improvement of environmental hygiene and sanitation as part of primary health care.
During the 10th Meeting of GET 2020 (31), the following recommendations were adopted to facilitate implementation of the SAFE strategy:
All endemic countries should establish collaboration with the WHO GET 2020 Secretaria
All endemic countries, particularly the more populous countries, should continue to assess the distribution and severity of trachoma, e.g. by rapid assessment
Countries should develop their strategic 5-year national trachoma plans, in collaboration with national and international partners, reflecting the commitment to implement the SAFE strategy; these plans should be integrated into their VISION 2020 national plans (WHA Resolution 56.26).

WHO should design methods and tools for assessing the trachoma burden and for certifying elimination of the disease.
Countries should endeavour to increase coverage of all the components of the SAFE strategy to the highest possible level.
In countries in which active trachoma prevalence has declined to < 5%, rapid assessment might be the most useful tool for identifying communities that need trachoma control activities as a priority in order to eliminate remaining pockets of the disease.
Countries should institute an ongoing audit of the quality of trichiasis surgery on the basis of the WHO guidelines for assessment (32)
Increased intersectoral collaboration should be instituted at national and district levels to ensure comprehensive implementation of all components of the SAFE strategy.
WHO and the international development community should advocate and promote trachoma as a marker of poverty and GET 2020 as a model of a public–private partnership for tackling the problem.
Target

By 2020, all 49 countries where endemic trachoma has been confi rmed should have achieved their ultimate intervention goals. The countries with plans for achieving those goals are shown in table 3
Indicators
number of countries with blinding trachoma as a public health problem;
proportion of endemic communities covered by the SAFE strategy;
recommended, where applicable:
• prevalence of trachomatous entropion trichiasis at district level;
• prevalence of active trachoma in 1–9-year-olds at district level; and
• progress in achieving the ultimate intervention goals.


National data are being used to refi ne ultimate intervention goals and annual intervention objectives in countries. The data are included in WHO information on neglected tropical diseases, in the WHO Global Health Atlas and in the WHO Infobase.