Prevention of Blindness and Eye Care

Data from prevalence surveys conducted by the Pan American Health Organization in nine (9) countries revealed that the marginal and poor populations are who have a higher prevalence of blindness and visual disability. The burden of visual impairment in Latin America and the Caribbean is not distributed uniformly; in many countries it is estimated that for every 1 million population 5,000 are blind, and 20,000 are visually impaired, at least two thirds are attributable to treatable conditions such as cataract, refractive errors, diabetic retinopathy, childhood blindness, glaucoma, onchocerciasis and trachoma.

• Introduction
• Cataract
• Uncorrected refractive errors in school children
• Blindness from diabetic retinopathy
• Blindness in premature babies
• Comprehensive low vision care

Data from prevalence surveys conducted by the Pan American Health Organization in nine (9) countries revealed that the marginal and poor populations are who have a higher prevalence of blindness and visual disability. The burden of visual impairment in Latin America and the Caribbean is not distributed uniformly; in many countries it is estimated that for every 1 million population 5,000 are blind, and 20,000 are visually impaired, at least two thirds are attributable to treatable conditions such as cataract, refractive errors, diabetic retinopathy, childhood blindness, glaucoma, onchocerciasis and trachoma. In the last 5 years the access to the eye health services has been increased in the marginal urban areas and rural areas of many countries of the region with support of PAHO - WHO, Vision 2020, international NGOs, and bilateral cooperation. At the national level, it is necessary that the Ministries of Health develop national ocular health plans, implement programs and mobilize the necessary resources to strength the supply of eye care services especially in areas and population groups where do not exist.

In Latin America and the Caribbean, cataract (opacification of the lens) is the single most important cause of blindness; cataract surgery has been shown to be one of the most cost effective interventions of all health care interventions. Most cataracts are age related and so cannot be prevented, but cataract surgery with insertion of an intraocular lens (IOL) is highly effective, giving almost immediate visual rehabilitation.

The prevalence of blindness in people aged 50 years and above varied from 2.3% to 3% in the national surveys in Venezuela and Paraguay; in the urban areas of Campinas, Brazil and Buenos Aires, Argentina it is of 1.4% and close to 4% in the rural areas of Peru and Guatemala. The proportion of blindness due to cataract in people aged 50 years and above varied in a range from 39% in the urban areas of Brazil and Argentina to about 65% in the rural areas of Peru and Guatemala. The national assessments revealed that close to 60% of blindness is due to cataract. The eye care services coverage for eyes with severe visual impairment is close to 80% in well developed urban areas and under 10% in the rural and remote areas.

What needs to be done?

• Increase provision of cataract surgical services to underserved population in each country.
• Measure prevalence of cataract blindness, coverage of services and barriers in selected countries.

Uncorrected refractive errors in school children

Good vision is vitally important in education, screening at school age is recommended. Studies on the prevalence of refractive errors in school age children (5-15 years of age) show that the magnitude of the problem varies among ethnic groups. A study in Chile revealed that more than 7% of children could benefit from the provision of proper spectacles.

The incidence of myopia is higher in the 11-15 age groups; this is the highest priority although in countries where there is evidence that younger children have a high prevalence of refractive errors and resources are available these children should be screened.

• Elaborate regional principles in refractive errors programs.
• Develop and follow national refractive errors programs

The prevalence of diabetes among adults in Latin America and the Caribbean varies among countries. It is estimated that approximately 50% of diabetics are unaware they have the condition. More than 75% of patients who have had diabetes mellitus for more than 20 years will have some form of diabetic retinopathy. After 15 years of diabetes, approximately 2% of people become blind, and about 10% develop severe visual handicap.

The prevalence of Diabetes mellitus affecting persons 40-84 of African descent in Barbados is high, with 18% of the population giving a diabetes history predominantly of older-onset. In the Barbados Eye Study 30% of persons with diabetes had diabetic retinopathy and 1% had proliferative diabetic retinopathy.

Evidence-based treatment is available to reduce significantly the risks for blindness and for moderate vision loss. Clinical studies spanning more than 30 years have shown that appropriate treatment can reduce the risks by more than 90%.

What needs to be done?

• Perform situation analysis of management of diabetic retinopathy in the Region as base for planning and advocacy.
• Integrate the prevention of blindness strategies in the national diabetes programs, and ensure that they are incorporated into non- communicable chronic diseases programs.

Blindness in premature babies

In Latin America and the Caribbean an estimated 42,000 babies with birth weight of less than 1,500 gm. require screening for R Retinopathy of the premature babies and 4.300 need treatment every year, untreated 50% of these babies will become blind.

Primary prevention: reduce the incidence of ROP through improved pre and neonatal care. This includes good antenatal care, good obstetric care, and meticulous neonatal care, particularly with respect to oxygenation – vital role of nurses. Follow up of preterm babies, screening babies at risk – neonatologists or neonatal nurses should identify babies to be examined.

Secondary prevention: early identification of severe cases of ROP by regular examination by a skilled ophthalmologist of premature babies in neonatal care and timely treatment of those with “high risk” ROP

Tertiary prevention: restore useful vision in children with retinal complications through vitreoretinal surgery (stage 4 ROP, not for stage 5) and or offer rehabilitation.

What needs to be done?

• Improve coverage and quality of Retinopathy of Prematurity (ROP) Programs.
• Improve quality of information on neonatal care.
• Increase public awareness and education in ROP and other prematurity health.

Despite major advances in eye care there is a significant number of persons of all age groups who cannot have their sight fully restored. The majority of these have some residual vision that can be enhanced or made more useable and utilized for tasks that require vision. Benefits of Low Vision Care reduces the functional impact of vision loss, facilitates child education and development, maintains independence, maintains productive activity, enhances quality of life, improves life satisfaction.

It is estimated that for every million population there are 17.000 people with low vision, one third of this would have an important functional improvement with the low vision care. These numbers are rapidly increasing due to aging of the populations in both developed and more importantly in developing countries and the increasing "epidemic" of diabetes related vision loss.

About 900 children per million populations require low vision care, 106 early intervention and 230 require educational support. An important cause is the increasing of retinopathy of prematurity in Latin America.

What needs to be done ?

• Increase access and demand to comprehensive low vision services to people with visual impairment.
• Develop national policies on comprehensive low vision care.

Information resources

Related Sites:

World Health Organization. Blindness

Documents:

Resolutions

CD49/19. Directing Council. Washington,D.C., 28 September-2 October 2009..

A56.26 Elimination of avoidable blindness

WHA59.25 Prevention of avoidable blindness and visual impairment

Initiatives and plans

Format for a Strategic a National Strategic Plan (in Spanish)

Plan of Action on the Prevention of Avoidable Blindness and Visual Impairment. 28 September - 2 October 2009.

Global Initiative for the Elimination of Avoidable Blindness

Strategic Plan for Vision 2020: The Right to Sight. Caribbean Region

 

Guidelines, manuals, and technical documents

 

Guía de atención básica en baja visión para oftalmólogos generales (en español)

 

 

Guidelines for Development for Eye Care Programs and Services in the Caribbean

Manual for the Training of Primary Health Workers in Eye Care

Unit of Health Services Organization. Eye Diseases in People 40-84. The Barbados Eye Studies

Contact information: