The status of childhood blindness and functional low vision in the Eastern Mediterranean region in 2012.

Childhood blindness and visual impairment (CBVI) are major disabilities that compromise the normal development of children. Health resources and practices to prevent CBVI are suboptimal in most countries in the Eastern Mediterranean Region (EMR). We reviewed the magnitude and the etiologies of childhood visual disabilities based on the estimates using socioeconomic proxy indicators such as gross domestic product (GDP) per capita and <5-year mortality rates. The result of these findings will facilitate novel concepts in addressing and developing services to effectively reduce CBVI in this region. The current study determined the rates of bilateral blindness (defined as  Best corrected visual acuity(BCVA)) less than 3/60 in the better eye or a visual field of 10° surrounding central fixation) and functional low vision (FLV) (visual impairment for which no treatment or refractive correction can improve the vision up to >6/18 in a better eye) in children <15 years old. We used the 2011 population projections, <5-year mortality rates and GDP per capita of 23 countries (collectively grouped as EMR). Based on the GDP, we divided the countries into three groups; high, middle- and low-income nations. By applying the bilateral blindness and FLV rates to high, middle- and low-income countries from the global literature to the population of children <15 years, we estimated that there could be 238,500 children with bilateral blindness (rate 1.2/1,000) in the region. In addition, there could be approximately 417,725 children with FLV (rate of 2.1/1,000) in the region. The causes of visual disability in the three groups are also discussed based on the available data. As our estimates are based on hospital and blind school studies in the past, they could have serious limitations for projecting the present magnitude and causes of visual disabilities in children of EMR. An effective approach to eye health care and screening for children within primary health care and with the available resources are discussed. The objectives, strategies, and operating procedures for child eye-care are presented. Variables impacting proper screening are discussed. To reach the targets, we recommend urgent implementation of new approaches to low vision and rehabilitation of children.

INTRODUCTION

In 1989, the United Nations adopted a convention on the rights of the child (CRC). A major article of this convention is the right of children to have access to the highest attainable standard of health and to the facilities for the treatment of illness and subsequent rehabilitation. It also includes the right of children with any kind of disability to special care and support.1 In 2009, a 20-year review of the CRC identified various challenges facing member states in the implementation of this article. It determined that the limited allocation of resources to be a significant factor in hampering optimal physical and mental development of children in many parts of world.2

Childhood blindness and visual impairment (CBVI) has a significant effect on the physical, mental, and social development of a child. Therefore, childhood blindness remains a priority disease of the global initiative for the elimination of avoidable blindness by the year 2020: "VISION 2020 - The Right to the Sight".3 All 23 countries of the Eastern Mediterranean Region (EMR) were signatories to the CRC and World Health Organization (WHO) resolutions on the VISION 2020 and Millennium Developmental Goals.4 Measures to address the rights of children unfortunately have not been adequately or uniformly implemented. In order to identify effective methods to provide optimal child eye heath care within a comprehensive health delivery system, we assessed the magnitude and causes of CBVI in children in the EMR. CBVI mainly includes bilateral blindness and functional low vision (FLV). Bilateral blindness is defined as the best-corrected visual acuity (BCVA) of less than 3/60 in the better eye or field of vision restricted to 10° around central fixation. FLV is defined as visual impairment for which no treatment or refractive correction can improve the vision up to >6/18 in a better eye. Our previous publication covered important aspects of visual disabilities in children in EMR.5 However, civil conflicts have affected the economy of many middle eastern countries in the previous 5-year.6 Children, as the highest at-risk population, are often the most affected in these conflicts. Due to new conflicts arising in the area, it is likely that factors affecting visual disabilities in children might have changed, thus warranting a re-examination of this issue and a new analysis for the regional countries.

MAGNITUDE OF THE PROBLEM

Evidence-based information on the magnitude of certain health issues is vital for an appropriately enhanced approach in the public health sector.7 Elimination of preventable childhood blindness is one of the priorities of the "VISION 2020 - The Right to the Sight" initiative in the subcontinent. Estimates show that there are 1.4 million blind children living in the middle- and low-income countries. Of these blind children, 200,000 were projected to be blind in member countries of the WHO EMR.8 The report further states that every year, an additional 50,000 children go blind in worldwide.9

Community-based prevalence surveys for childhood blindness are essential in creating roadmaps to manage this health issue. However, they require a large sample and are costly. Therefore, conducting these surveys is a major challenge in developing countries where there are competing demands for financial resources.10 In such circumstances, creation of alternative methods to estimate the magnitude and identify causes of childhood blindness must be considered.

As an example, gross domestic product (GDP) per capita and mortality rates of children < 5-year of age have been shown to be reliable proxy indicators to determine the magnitude of childhood blindness.11 These are reliable indicators due to the intimate relationship between some causes of blindness (measles, Vitamin A deficiency, ophthalmia neonatorum, rubella, etc.) and diseases with high morbidity and mortality in developing countries. Developing countries have a low level of socioeconomic development and suboptimal health resources to prevent or treat these conditions. To estimate the number of children with bilateral blindness in each EMR country on basis of socioeconomic indices such as GDP and under 5-year of age mortality rate, we grouped the 23 EMR countries into 3 categories using the data from the 2011 annual report of the Regional Director of WHO EMR.12 Countries with GDP over US$15,000 were classified as Group 1, countries with GDP of US$1,500-US$15,000 were classified in Group 2 and countries with GDP < US$1,500 were classified in Group 3. We also grouped the countries into three sets based on the childhood mortality rates of under 5-year of age: Set 1 included children with a mortality rate of < 20/1,000 live births; Set 2 with a mortality rate between 20 and 50/1,000 live births and; Set 3 countries with a mortality rate > 50/1,000 live births [Figure 1]. We determined that this classification coincided well with the GDP grouping of countries.

Figure 1

Gross domestic product in US$ and <5 mortality per 1000 live births in member countries of Eastern Mediterranean Region of the World Health Organization

For each group, we applied a blindness prevalence rate obtained from countries with similar GDP. Thus, for Group 1 countries, the rate was tabulated to be 0.3/1,000, for Group 2, it was 0.9/1,000, and for Group 3, it was 1.5/1,000.11 These data were used to calculate the number of children with bilateral blindness in an individual EMR country [Table 1]. We determined that the bilateral blindness rate in the EMR region was 1.2/1,000 children < 15-year of age. This translates to a 238,500 bilateral blind children across the entire EMR countries. Two-thirds were distributed in seven countries in Group 3 (with low GDP and high mortality rates among < 5-year-old children).

Table 1

Estimated bilateral blindness and FLV in children aged 15-year or younger in member countries of EMR of the WHO

We also calculated the number of children with FLV. We used data from a multicenter study of schoolchildren across countries based on their level of their GDPs already grouped into 1-3 from low to high. In Group 1, for countries with highest GDP, we used the FLV rate (0.3/1000) in South Africa with GDP of US$11,273 in 2010.1314 In Group 2, the FLV rate was projected to be 1.87 as reported for Nepal with GDP of US$1,388/capita). In Group 3, the rate was assumed to be 2.5/1,000 children as reported in India with a GDP US$1,455 in 2010. Table 1 presents the FLV of 23 countries. The FLV rate was 2.1/1,000 children under 15-year of age, and 417,725 children had FLV in the EMR region. As our estimates are based on the hospital and blind school studies in the past, they could have serious limitations for projecting the magnitude and causes of visual disabilities in children in EMR. Community-based prevalence data would be more accurate for national public health planning.

CAUSES OF CHILDHOOD BLINDNESS AND VISUAL IMPAIRMENT

Studies have been conducted to review the anatomical and etiological causes of BCVI in children in the EMR.151617181920 These are mostly institution based studies, undertaken in schools for special needs children or schools for the blind. Other studies were hospital and community-based2122232425 [Table 2]. However, valid data on the true causes of overall FLV among children in the EMR are scarce.

Table 2

Different studies in EMR highlighting the causes of childhood blindness

In industrialized countries, central visual function defects due to perinatal and hereditary causes (in USA, Europe and Western pacific countries), retinal dystrophies, and retinopathy of prematurity (ROP) are the leading causes of childhood blindness.26 In contrast, infection, malnutrition, trauma, uncorrected refractive error, and un-operated cataract are leading causes of visual disabilities in developing countries.27 In developing countries, the majority of these conditions are avoidable or treatable with improved access to medical care, routine visual screening and the appropriate action of care.28 In the emerging EMR market-nations, a combination of various causes of FLV is noted. Additional factors contributing to the intricacy of FLV in children are the high rate of consanguineous marriages, unacceptable therapeutic abortions, and the high birth rates.2930313233 Improved access to health care and improved delivery of health care especially related to maternal and child health care in most of the aforementioned countries have resulted in better survival of preterm children. However, these improvements have resulted in an increase in the rate of ROP and its severity at presentation.34 These factors have resulted in a steady rise of central visual deficits and birth defects with ROP and cataract as the more common causes of visual deficits and declining rates of infectious and nutritional causes in Group 1 and 2 countries.35 In Group 3 countries, corneal blindness due to Vitamin A deficiencies, infections, and war-related injuries remain the primary etiology of visual deficits.36

MEASURES TO ADDRESS THE PROBLEM

In a recent study, Limburg et al. reported that 36.4% of childhood blindness were due to uncorrected refractive error in developing countries. Among children at blind schools, one-fourth of visual disability was retina-or corneal-related.37 The study showed that many childhood visual disabilities are preventable, and the rest may be addressed through rehabilitation to improve vision related quality-of-life. The needed intervention is dependent on the available infrastructure for primary health care and eye-care within a country.

Preventive measures

To properly design appropriate and relevant measures to address the optimal public health approaches in reducing the CBVI will be a complex and an immense undertaking due to the diverse causes of childhood blindness in the EMR. The EMR countries have committed themselves in reaching the Millennium Development Goals.4 With specific public health initiatives, a number of preventive measures could be introduced and reinforced to address nutritional, childhood infection, and injury-related eye problems in children. Integrating primary pediatric eye-care screening with the preexisting primary health care delivery in school settings and community-based outreach programs will allow for an early detection of disabling eye diseases in children.3839 This will enable eye care providers to detect and prevent blinding eye conditions at early stages, that is, xerophthalmia, blindness secondary to measles, rubella, and ocular trauma. This could also be a channel for advocacy for healthy eye practices, providing first aid for eye emergencies and guiding children with visual disabilities for rehabilitation. Close collaboration of all stakeholders responsible for children's overall health like pediatricians, sociologists, parents, family physicians, community support groups, etc., could further enhance a better eye care screening, delivery, and treatment of diseases for all children.

Curative measures

Refractive error is a major cause of the slow rise in ocular morbidity in the EMR. The prevalence was 13.7% in Saudi children, and 22.1% in Egypt.4041 Mid-level eye care personnel can manage refractive error in children and could provide and maintain visual aids at an affordable cost.42 Screening for amblyopia in 3-5-year-old children, vision-screening for all preterm infants regardless of their previous ROP status, as well as vision-screening programs for all school age children for refractive errors, have been found to be cost-effective measures in the literature.434445 At the minimum, we recommend implementation of these programs through the national eye health care programs of Group 1 and 2 countries.

Furthermore, we advise direct management of other ocular conditions like retinal dystrophies, ROP, congenital cataract, congenital glaucoma, strabismus, keratoconus, etc., to be done vis-a-vis pediatric ophthalmologists or general ophthalmologists oriented in pediatric ophthalmology. New ophthalmology centers of excellence providing direct access to health-care professionals within the already existing secondary/tertiary pediatric eye hospitals would ultimately establish the gold-standard approach in management of conditions leading to childhood blindness.

Late interventions often compromise the outcomes of ocular pathologies leading to childhood blindness. However, following the intervention, the child can utilize the residual vision and use low vision aids to improve his/her quality-of-life.46 As a result, for disabled children especially in Group 3 countries, maximum efforts should be dedicated to allocate proper resources in identifying treatable blindness even if such conditions present in the late stages or are initially detected at an older age.

The following lists are the suggested goals for managing some of the common causes of visual impairment and blindness in children:

The goal of managing a child with congenital cataract:

Significant visual impairment due to cataract should undergo timely surgery using age appropriate and evidence-based surgical techniques

To stimulate further development of the visual system by enabling clear images in both eyes

To offer functional vision to a child with cataract, provide low vision rehabilitation services in time and monitor changes in quality of life

The goal of managing a child with ROP:

To arrest the progression of ROP.

To monitor short and long-term outcomes of ROP management

To offer refraction, low vision care and if needed, rehabilitation

The goal of managing a child with strabismus:

To determine the underlying cause of strabismus.

To treat amblyopia and refractive correction as needed.

To ensure cosmesis by proper use of spectacles and surgery as needed

To optimize binocularity.

Low vision services

Despite the best preventive and curative measures, some children will continue to remain visually impaired. In such cases, low vision rehabilitation services are warranted to ensure that these children live a near normal life. There is a major emphasis on integrating low vision care within VISION 2020 and a plan for better implementation of low vision care in the member countries. Using the key informant method in the community is another approach adopted in underprivileged countries to locate children with visual disabilities.47 Already existing studies from the hospital based-data, although biased in a number of ways, are rich sources of information in providing additional methods of care on childhood blindness.23 Changing trends of childhood blindness has made it mandatory for Group 1 and 2 countries to adopt new programs to integrate low vision rehabilitation of children into VISION 2020. The International Agency for the Prevention of Blindness - EMR has taken the initiative to plan low vision care in the region.48 A selective and focal approach was adopted in the past by Oman, Qatar, UAE, Saudi Arabia, Pakistan, etc.49 An institutional-based approach for low vision care needs to be complimented by community-based rehabilitation. Children with other sensory impairments have a higher risk of abnormal visual function.50 Thus, countries with limited resources can begin focusing on low vision care services targeting children in schools for the blind, schools for the deaf, and schools for the mentally challenged. Ironically, half of the children studying in schools for the blind have low vision disability rather than absolute blindness, and a more individualistic approach is needed for these children.51 Integrated and collaborative medical teams, consisting of orthoptists, pediatric optometrists, etc., would certainly enhance and build the necessary bridges in providing a better care and improving access as well as implementing preventive medicine. Hence, adopting a multi-disciplinary approach and involving all the stakeholders in the childcare is crucial for success.52

Human resources need

Limited resources for addressing childhood blindness are a major challenge in many member states in EMR. The emphasis on developing human resources and pediatric eye care service centers, as "centres of excellence" was recommended in 2002.53 Murthy et al. evaluated these resources in India and found them inadequate and not appropriately distributed.54 Similar evaluation and monitoring are required in countries in EMR region. If we use the estimate of one pediatric ophthalmologist at one child eye-care center with a well-trained team for a target population of 10 million people, we will need a minimum of 60 pediatric ophthalmologists in EMR region.55 The WHO recommended ratio of one optometrist to every 50,000 population cohort might be a suitable basis for good eye-care.56 However, local optometrists require training for providing child eye-care. The time required for training is nearly 2-3 years. However, more optometrists (more than 1,200) will be required by the time the training is complete due to the continual increase in the younger population in the region. In addition, a skilled work force (of optometrists) is found mainly in the urban areas while the rural population with more childhood blindness has difficult access to health care services. If the doctors work with other team members, eye-care delivery will be enhanced. In countries, where the primary health care system is not organized in all parts of the country, eye-screening centers could be developed in such areas, and children with ocular pathologies could be referred to the centers of excellence. Few training centers are supported by the International Nongovernmental Organisations related to the prevention of blindness in the region.

Child eye health practices should be instituted at the community as well as at the primary, secondary, and tertiary health care levels and with a direct engagement of other social public sectors ranging from social welfare to education and others. Teamwork in addressing the childhood visual impairment and blindness must be the ultimate goal. We present a schematic diagram to address CBVI, depicting intervention at different health care levels [Figure 2].

Figure 2

Schematic diagram for addressing childhood blindness at different health care levels

Reviews of the screening programs and models of vision and eye examination for children have confirmed their benefits. Carlton et al. suggested that amblyopia screening at 3 or 4 years of age is cost-effective.57 A subsequent review by Schmucker et al. revealed uncertainty about age at which treatment of amblyopia remains effective.58 Although vision improved following amblyopia treatment, its impact on vision related quality-of-life was low.59 Mema et al. justified preschool screening program for amblyopia detection and care that is ongoing in different provinces in Canada.43 The EMR countries with school health programs and vision screening programs could adapt a suitable model for early detection of amblyopia and its causes.

Health staff at the primary level can contribute significantly to prevent eye morbidity in children. The proposed role of the primary health care worker is given below.

Primary health care staff should perform the following functions:

Judiciously implement visual screening for developmental milestones during the vaccination visit of children

Consult an ophthalmologist for ROP screening if a baby is born <2000 g or <32 weeks and rule out ROP in case a newborn has respiratory distress syndrome

Perform vision screening of preschool children

Diagnose and treat Vitamin A deficiency, infective conjunctivitis and allergic conjunctivitis

Use trachoma grading card to diagnose active trachoma and treat the case as per accepted medical protocols

Advocate preventive eye measures to avoid infectious eye diseases and take the appropriate educational activities in the prevention of ocular injuries

Detect and treat cases of chronic allergic conjunctivitis leading to secondary keratopathy

Promptly refer ocular emergencies to an ophthalmologist

Refer children who fail a screening test to experienced ophthalmologists

Counsel children and parents to comply with the medical advice from eye-care professionals (surgery, spectacles, etc.).

The role of general ophthalmologists in child eye health cannot be overemphasized. In settings where there is no pediatric ophthalmologist, the general ophthalmologists will take many of the roles of the pediatric ophthalmologists. The following are the minimal roles suggested for the general ophthalmologists:

Comprehensive eye assessment of children referred with a diagnosis of cataract, glaucoma, low vision, ROP, amblyopia, and ocular birth defects

Treat common eye conditions (allergic conjunctivitis, infectious conjunctivitis, etc.)

Liaise with pediatrician to evaluate systemic pathologies as part of ocular syndrome

Liaise with anesthetist to determine the status of the child for surgical intervention under general anesthesia (in children with significant cataract, glaucoma, ocular malignancies, etc.)

Refer cases to a pediatric ophthalmologist at tertiary eye centers as warranted

Follow treatment and follow-up plan after child has been assessed/treated by a pediatric ophthalmologist.

There were some limitations to our study. Countries (Syria, Libya and Yemen) that faced civil disturbances in 2011 and 2012 may have different < 5 mortality rates and GDP than that documented based on mid - 2011 data, thus skewing our reported results. Some demographics may vary such as high fertility rate, higher consanguinity, late pregnancies, use of traditional medicine etc., resulting in higher prevalence of FLV and blindness in this region compared to the developed countries. We urge caution in interpreting our final data as the rates and causes of blindness and FLV are based on hospital and blind school data of studies in the past and extrapolation to EMR countries may result in inaccurate conclusions. Hence, our study likely underestimates the rates of blindness and FLV in these countries. In large countries with dense population centers, the situation within certain governorates or provinces may vary and fluctuate. Therefore, the scenario of childhood blindness in such countries should be reviewed with caution, and further planning to address childhood blindness should be carried out on a smaller scale level. Although uncorrected refractive error in children could be a major contributor in visual disabilities, the definition used for calculating possible blindness did not include this subset of children. Hence, the FLV data should be interpreted with caution while planning refractive error services.

In summary, current studies on childhood blindness give enough evidence-based information, albeit with certain shortcomings, to plan and strengthen a public health approach in appropriately dealing with childhood blindness in the region. Rehabilitation of children with visual disabilities should be part of the public health program of an individual country. Further research to generate evidence on the cost-effectiveness of screening for amblyopia and its long-term utility on visual loss and the best approaches are recommended. Better methodologically designed studies in a cohort of selective population of the region would allow a re-evaluation and revision of the program strategies for dealing with this complex health issue.