|Year : 2014 | Volume
| Issue : 4 | Page : 336-343
The Status of Childhood Blindness and Functional Low Vision in the Eastern Mediterranean Region in 2012
Rajiv Khandekar1, H Kishore2, Rabiu M Mansu3, Haroon Awan4
1 Department of Research, King Khalid Eye Specialist Hospital, Riyadh, Saudi Arabia
2 Department of Pediatric Ophthalmology, Al Nahdhah Hospital, Ministry of Health, Oman
3 Middle East Africa and IMPACT NGO, Riyadh, Saudi Arabia
4 Avicenna Consulting Pvt Ltd., Islamabad, Pakistan
|Date of Web Publication||4-Oct-2014|
Department of Research, King Khaled Eye Specialist Hospital, POB: 7191, Riyadh 11462,
Source of Support: None, Conflict of Interest: None
| Abstract|| |
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.
Keywords: Childhood Blindness, Eastern Mediterranean Region, Functional Low Vision, Visual Disability
|How to cite this article:|
Khandekar R, Kishore H, Mansu RM, Awan H. The Status of Childhood Blindness and Functional Low Vision in the Eastern Mediterranean Region in 2012. Middle East Afr J Ophthalmol 2014;21:336-43
|How to cite this URL:|
Khandekar R, Kishore H, Mansu RM, Awan H. The Status of Childhood Blindness and Functional Low Vision in the Eastern Mediterranean Region in 2012. Middle East Afr J Ophthalmol [serial online] 2014 [cited 2019 Dec 10];21:336-43. Available from: http://www.meajo.org/text.asp?2014/21/4/336/142273
| 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.  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. 
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".  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.  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.  However, civil conflicts have affected the economy of many middle eastern countries in the previous 5-year.  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.  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.  The report further states that every year, an additional 50,000 children go blind in worldwide. 
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.  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.  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.  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$1,500 were classified in Group 3. We also grouped the countries into three sets based on the childhood mortality rates of under 5-year of age: Set 1 included children with a mortality rate of < 20/1,000 live births; Set 2 with a mortality rate between 20 and 50/1,000 live births and; Set 3 countries with a mortality rate > 50/1,000 live births [Figure 1]. We determined that this classification coincided well with the GDP grouping of countries.
For each group, we applied a blindness prevalence rate obtained from countries with similar GDP. Thus, for Group 1 countries, the rate was tabulated to be 0.3/1,000, for Group 2, it was 0.9/1,000, and for Group 3, it was 1.5/1,000.  These data were used to calculate the number of children with bilateral blindness in an individual EMR country [Table 1]. We determined that the bilateral blindness rate in the EMR region was 1.2/1,000 children < 15-year of age. This translates to a 238,500 bilateral blind children across the entire EMR countries. Two-thirds were distributed in seven countries in Group 3 (with low GDP and high mortality rates among < 5-year-old children).
|Figure 1: Gross domestic product in US$ and <5 mortality per 1000 live births in member countries of Eastern Mediterranean Region of the World Health Organization|
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|Table 1: Estimated bilateral blindness and FLV in children aged 15-year or younger in member countries of EMR of the WHO |
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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. , 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. ,,,,, These are mostly institution based studies, undertaken in schools for special needs children or schools for the blind. Other studies were hospital and community-based ,,,, [Table 2]. However, valid data on the true causes of overall FLV among children in the EMR are scarce.
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.  In contrast, infection, malnutrition, trauma, uncorrected refractive error, and un-operated cataract are leading causes of visual disabilities in developing countries.  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.  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. ,,,, 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.  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.  In Group 3 countries, corneal blindness due to Vitamin A deficiencies, infections, and war-related injuries remain the primary etiology of visual deficits. 
|Table 2: Different studies in EMR highlighting the causes of childhood blindness |
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| 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.  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.
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.  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. , 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.
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. , Mid-level eye care personnel can manage refractive error in children and could provide and maintain visual aids at an affordable cost.  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. ,, 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.  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.  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.  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.  A selective and focal approach was adopted in the past by Oman, Qatar, UAE, Saudi Arabia, Pakistan, etc.  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.  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.  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. 
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.  Murthy et al. evaluated these resources in India and found them inadequate and not appropriately distributed.  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.  The WHO recommended ratio of one optometrist to every 50,000 population cohort might be a suitable basis for good eye-care.  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|
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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.  A subsequent review by Schmucker et al. revealed uncertainty about age at which treatment of amblyopia remains effective.  Although vision improved following amblyopia treatment, its impact on vision related quality-of-life was low.  Mema et al. justified preschool screening program for amblyopia detection and care that is ongoing in different provinces in Canada.  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.
| References|| |
|1.||United Nations Convention on the Rights of a Childhttp. Available from: http://www. 2.ohchr.org/english/law/crc.htm. [Last accessed on 2013 Jan 22]. |
|2.||Seymour D. 1989-2009. Convention brings progress on child rights, but challenges remain. Available from: http://www.unicef.org/rightsite/237.htm. [Last accessed on 2013 Jan 22]. |
|3.||Babalola OE. Addressing residual challenges of VISION 2020: The right to sight. Middle East Afr J Ophthalmol 2011;18:91-2. |
|4.||Mittelmark MB. Millenium Development Goals. Glob Health Promot 2009;16:3-4, 73-4, 88-9. |
|5.||Khandekar R. Visual disabilities in children including childhood blindness. Middle East Afr J Ophthalmol 2008;15:129-34. |
|6.||Mowafi H. Conflict, displacement and health in the Middle East. Glob Public Health 2011;6:472-87. |
|7.||Qureshi MB, Al-Rajhi A, Al-Qureshi S. The need for evidence-based planning for VISION 2020. Clin Experiment Ophthalmol 2012;40:423-4. |
|8.||World Health Organization Eastern Mediterranean Region. Statistics and Figures in Control of Prevention of Blindness and Deafness. Available from: http://www.emro.who.int/control-and-preventions-of-blindness-and-deafness/about-the-programme/about-the-programme.html. [Last accessed on 2013 Jan 05]. |
|9.||World Health Organization- Prevention of blindness and deafness. Childhood blindness in priority eye diseases. Available from: http://www.who.int/blindness/causes/priority/en/index4.html. [Last accessed on 2013 Jan 05]. |
|10.||Courtright P, Hutchinson AK, Lewallen S. Visual impairment in children in middle-and lower-income countries. Arch Dis Child 2011;96:1129-34. |
|11.||Gilbert C, Foster A. Childhood blindness in the context of VISION 2020 - The right to sight. Bull World Health Organ 2001;79:227-32. |
|12.||World Health Organization. Country statistical profile in 'The work of WHO in the Eastern Mediterranean Region: Annual report of the Regional Director 1 January-31 December 2011'. Available from: http://www.emro.who.int/about-who/annual-reports/annual-report-2011.html. [Last accessed on 2013 Jan 07]. |
|13.||Gilbert CE, Ellwein LB, Refractive Error Study in Children Study Group. Prevalence and causes of functional low vision in school-age children: Results from standardized population surveys in Asia, Africa, and Latin America. Invest Ophthalmol Vis Sci 2008;49:877-81. |
|14.||Global Finance GDP data of South Africa, India and Nepal in 2010. Available from: http://www.gfmag.com/gdp-data-country-reports/255-india-gdp-country-report.html#axzz2subDsSFU. [Last accessed on 2014 Feb 10]. |
|15.||Al-Wadani F, Khandekar R, Al-Hussain MA, Alkhawaja AA, Khan MS, Alsulaiman RA. Magnitude and Causes of Low Vision Disability (Moderate and Severe Visual Impairment) among Students of Al-Noor Institute for the Blind in Al-Hassa, Saudi Arabia: A case series. Sultan Qaboos Univ Med J 2012;12:62-8. |
|16.||Kazmi HS, Shah AA, Awan AA, Khan J, Siddiqui N. Status of children in blind schools in the northern areas of Pakistan. J Ayub Med Coll Abbottabad 2007;19:37-9. |
|17.||Mirdehghan SA, Dehghan MH, Mohammadpour M, Heidari K, Khosravi M. Causes of severe visual impairment and blindness in schools for visually handicapped children in Iran. Br J Ophthalmol 2005;89:612-4. |
|18.||Khandekar R, Shah R, Shah M, Al Harby S, Vora U, Al Balushi F. Ocular status and functional adaptation of visually challenged children of a special school in Oman. Oman J Ophthalmol 2011;4:17-20. |
|19.||Kotb AA, Hammouda EF, Tabbara KF. Childhood blindness at a school for the blind in Riyadh, Saudi Arabia. Ophthalmic Epidemiol 2006;13:1-5. |
|20.||Sight Savers International. Current Status of the Aetiology, Prevalence And Distribution Of Childhood Blindness in Pakistan. Report 2003: 17-18. Available from: http://www.sightsavers.org/in_depth/policy_and_research/education/13177_Current%20status%20Childhood%20Blindness%20in%20Pakistan.pdf. [Last accessed on 2013 Jan 25]. |
|21.||Elder MJ, De Cock R. Childhood blindness in the West Bank and Gaza Strip: Prevalence, aetiology and hereditary factors. Eye (Lond) 1993;7:580-3. |
|22.||Tabbara KF, El-Sheikh HF, Shawaf SS. Pattern of childhood blindness at a referral center in Saudi Arabia. Ann Saudi Med 2005;25:18-21. |
|23.||Al-Merjan JI, Pandova MG, Al-Ghanim M, Al-Wayel A, Al-Mutairi S. Registered blindness and low vision in Kuwait. Ophthalmic Epidemiol 2005;12:251-7. |
|24.||Razavi H, Kuper H, Rezvan F, Amelie K, Mahboobi-Pur H, Oladi MR, et al. Prevalence and causes of severe visual impairment and blindness among children in the lorestan province of iran, using the key informant method. Ophthalmic Epidemiol 2010;17:95-102. |
|25.||Bamashmus MA, Al-Akily SA. Profile of childhood blindness and low vision in Yemen: A hospital-based study. East Mediterr Health J 2010;16:425-8. |
|26.||Kong L, Fry M, Al-Samarraie M, Gilbert C, Steinkuller PG. An update on progress and the changing epidemiology of causes of childhood blindness worldwide. J AAPOS 2012;16:501-7. |
|27.||Durnian JM, Cheeseman R, Kumar A, Raja V, Newman W, Chandna A. Childhood sight impairment: A 10-year picture. Eye (Lond) 2010;24:112-7. |
|28.||Maida JM, Mathers K, Alley CL. Pediatric ophthalmology in the developing world. Curr Opin Ophthalmol 2008;19:403-8. |
|29.||Hussain R. The effect of religious, cultural and social identity on population genetic structure among Muslims in Pakistan. Ann Hum Biol 2005;32:145-53. |
|30.||Yamamah G, Abdel-Raouf E, Talaat A, Saad-Hussein A, Hamamy H, Meguid NA. Prevalence of consanguineous marriages in South Sinai, Egypt. J Biosoc Sci 2013;45:31-9. |
|31.||Saha N, Hamad RE, Mohamed S. Inbreeding effects on reproductive outcome in a Sudanese population. Hum Hered 1990;40:208-12. |
|32.||Babay ZA. Attitudes of a high-risk group of pregnant Saudi Arabian women to prenatal screening for chromosomal anomalies. East Mediterr Health J 2004;10:522-7. |
|33.||Al-qudsi S. The demand for children in Arab countries: Evidence from panel and count data models. J Popul Econ 1998;11:435-52. |
|34.||Tasman W. Retinopathy of prematurity: Do we still have a problem? The Charles L. Schepens lecture. Arch Ophthalmol 2011;129:1083-6. |
|35.||Wani VB, Kumar N, Sabti K, Raizada S, Rashwan N, Shukkur MM, et al. Results of screening for retinopathy of prematurity in a large nursery in Kuwait: Incidence and risk factors. Indian J Ophthalmol 2010;58:204-8. |
|36.||Kheir AE, Dirar TO, Elhassan HO, Elshikh MA, Ahmed MB, Abbass MA, et al. Xerophthalmia in a traditional Quran boarding school in Sudan. Middle East Afr J Ophthalmol 2012;19:190-3. |
|37.||Limburg H, Gilbert C, Hon do N, Dung NC, Hoang TH. Prevalence and causes of blindness in children in Vietnam. Ophthalmology 2012;119:355-61. |
|38.||World Health Organization. Summary report on Regional workshop for integrating and strengthening primary eye care within primary health care in the Eastern Mediterranean Region. WHO-EM/CPB/008/E. 2011. Available from: http://www.applications.emro.who.int/docs/IC_Meet_Rep_2011_EN_14438.pdf. [Last accessed on 2013 Jan 7]. |
|39.||IAPB EMR/WHO EMRO. Guidelines for School Eye Health for the Eastern Mediterranean Region (EMR) 2009. Available from: http://www.pbunion.org/IMPACT-EMR-Guidelines-1.pdf. [Last accessed on 2013 Jan 7]. |
|40.||Al Wadaani FA, Amin TT, Ali A, Khan AR. Prevalence and pattern of refractive errors among primary school children in Al Hassa, Saudi Arabia. Glob J Health Sci 2012;5:125-34. |
|41.||El-Bayoumy BM, Saad A, Choudhury AH. Prevalence of refractive error and low vision among schoolchildren in Cairo. East Mediterr Health J 2007;13:575-9. |
|42.||Qureshi MB. Training to meet the need for refractive error services. Community Eye Health 2007;20:48-51. |
|43.||Mema SC, McIntyre L, Musto R. Childhood vision screening in Canada: Public health evidence and practice. Can J Public Health 2012;103:40-5. |
|44.||Fierson WM, American Academy of Pediatrics Section on Ophthalmology, American Academy of Ophthalmology, American Association for Pediatric Ophthalmology and Strabismus, American Association of Certified Orthoptists. Screening examination of premature infants for retinopathy of prematurity. Pediatrics 2013;131:189-95. |
|45.||World Health Organization, Prevention of Blindness and Deafness. Elimination of Avoidable Visual Disability Due to Refractive Errors: Report of an Informal Planning Meeting, Geneva, July 2000. Published Geneva, Switzerland; 2001. |
|46.||Gogate P, Khandekar R, Shrishrimal M, Dole K, Taras S, Kulkarni S, et al. Delayed presentation of cataracts in children: Are they worth operating upon? Ophthalmic Epidemiol 2010;17:25-33. |
|47.||Muhit MA, Shah SP, Gilbert CE, Hartley SD, Foster A. The key informant method: A novel means of ascertaining blind children in Bangladesh. Br J Ophthalmol 2007;91:995-9. |
|48.||Prevention of Blindness Union. Conference Recommendations. Doha Early Intervention Conference April 2011 held in Qatar. Available from: http://www.pbunion.org/files/LVR%20Workshop%20Documents/1.%20Agenda%20and%20other%20documents/Recommendations%20Doha%20Conference11May.pdf. [Last accessed on 2013 Jan 7]. |
|49.||Khandekar R, Mohammed AJ. Assessment and care of children with low vision disability in Oman. Situation analysis. Saudi Med J 2005;26:1028-30. |
|50.||Vora U, Khandekar R, Natrajan S, Al-Hadrami K. Refractive error and visual functions in children with special needs compared with the first grade school students in oman. Middle East Afr J Ophthalmol 2010;17:297-302. |
|51.||Woodhouse JM, Davies N, McAvinchey A, Ryan B. Ocular and visual status among children in special schools in Wales: The burden of unrecognised visual impairment. Arch Dis Child 2014;99:500-4. |
|52.||Hyvärinen L, Walthes R, Freitag C, Petz V. Profile of visual functioning as a bridge between education and medicine in the assessment of impaired vision. Strabismus 2012;20:63-8. |
|53.||World Health Organization. Five Year project for the Prevention of Childhood Blindness. Geneva: World Health Organization; 2002. p. 4-5.[WHO/PBL/02.88]. |
|54.||Murthy G, John N, Gupta SK, Vashist P, Rao GV. Status of pediatric eye care in India. Indian J Ophthalmol 2008;56:481-8. |
|55.||World Health Organization. A five-year project for the prevention of childhood blindness: Report of a WHO Consultation. Geneva: WHO; 2002. [WHO/PBL/02.88]. |
|56.||World Health Organization. Elimination of avoidable visual disabilities due to refractive error. Report of informal planning meeting in July 2000. P40. Available from: http://www.who.int/ncd/vision2020_actionplan/documents/WHO_PBL_00.79.pdf. [Last accessed on 2013 Jan 23]. |
|57.||Carlton J, Karnon J, Czoski-Murray C, Smith KJ, Marr J. The clinical effectiveness and cost-effectiveness of screening programmes for amblyopia and strabismus in children up to the age of 4-5 years: A systematic review and economic evaluation. Health Technol Assess 2008;12:iii, xi-194. |
|58.||Schmucker C, Kleijnen J, Grosselfinger R, Riemsma R, Antes G, Lange S, et al. Effectiveness of early in comparison to late (r) treatment in children with amblyopia or its risk factors: A systematic review. Ophthalmic Epidemiol 2010;17:7-17. |
|59.||Mathers M, Keyes M, Wright M. A review of the evidence on the effectiveness of children's vision screening. Child Care Health Dev 2010;36:756-80. |
[Figure 1], [Figure 2]
[Table 1], [Table 2]