Post on 08-Jan-2016
description
transcript
Richard Scawn, Dawn Sim, Charles ClaoueQueens Hospital, Essex, UK
Richard Scawn has received travel sponsorship from Rayner
The authors have no financial interest in the subject of this e-poster
• The aim of our study was to determine the causes of childhood blindness in Qatar
• One previous survey of blindness in adults and children of Qatar was carried out in 1977 1
• The State of Qatar is an Arab emirate bordered by Saudi Arabia and the Persian Gulf.
• With the discovery of oil in the 1940s came large changes in the socioeconomic wealth and population growth.
• It is estimated that only about 30% of the country’s population (>1.4million), are citizens.
• All Qataris receive free medical care
• Qatar’s only blind school
• Opened in September of 1998
• Provides a free education for citizens and residents
• Students with blindness, low vision, and special
needs
• A visiting Ophthalmologist examined all children attending the Al-Noor Institute
• The classification method used was that of the British Ophthalmological Surveillance Unit (BOSU) study 3
(1) entirely unavoidable/untreatable,
(2) entirely preventable, or
(3) potentially treatable
• Outcomes of the consultation were grouped into 7 categories, including recommendations for
(1) surgery, (2) further investigations, (3) low vision assessment, (4) refraction / contact lens / glasses, (5) mainstream school, (6) blind school(7) blind school with special needs
211 children examinedCauses of Childhood blindness in the Al-Noor
Institute
168
43
0
20
40
60
80
100
120
140
160
180
Genetic Acquired
Number of Children
Genetic causes Total (%)
Acquired causes Total (%)
MicrophthalmiaLeber’a AmaurosisRetinitis PigmentosaHigh MyopiaRetinal detachmentCongenital CataractsHomocystinuriaCongenital GlaucomaAlbinismCongenital nystagmusCone DystrophySquint/Refractive/AmbylopiaCongenital PtosisCorneal Opacities (Genetic)Neurological (Genetic)
18 (11)17 (10)5 (3)13 (8)8 (5)14 (8)41 (19)17 (10)4 (2)5 (3)2 (1)10 (6)1 (1)17 (10)7 (4)
Corneal Opacities (Acquired)Neurological (Acquired)Retinopathy of PrematuritySquint / AmbylopiaCongenital PtosisMacular Coloboma
5 (12)
13 (30)
13 (30)10 (23)1 (2)1 (2)
Total 168 (79)
43 (21)
Entirely unavoidable/untreatable
65 (30.8%)
Entirely preventable 25 (11.8%)
Retinopathy of prematurityTraumatic brain injuryRefractive error/Ambylopia
13111
Potentially treatable 121 (57.3%)
High MyopiaRetinal detachmentCongenital CataractsHomocystinuriaCongenital GlaucomaCorneal opacitiesCerebral palsyHydrocephalus
1381441172242
Categories 1977 Current Difference (%)
Trachoma 36 0.5 -35.6
Infectious diseases
6.1 1.4 -4.7
Retinal disease 15.0 27 +12.0
Trauma 23.8 1.4 -22.4
Genetically determined
17.0 79.8 +62.6
• Homocystinuria was by far the most common single diagnosis.
• In this group further intervention via cataract surgery or YAG laser capsulotomy required in 17% (n=7), refraction or low vision assessment was needed in 63% (n=26).
• A small number of these children (n=4, 9.8%) had visual acuities that would enable them to attend mainstream school.
• Homocystinuria incidence – Western Europe: 1 in 20,000-60,000 4 – Norway: 1 in 6400– Qatar: 1 in 3125 5
• Original Qatari tribes amount to about 200,000 people • Until the beginning of the 20th century the local Qatari
tribes were genetically isolated, with a high level of intermarriage.
• As in other Gulf States today it is still common for first- or second-degree cousins to marry6. 54% in Qatari population7
• Consequent founder effects are responsible for the high prevalence and unusual burden of inherited disorders in Qatari population8
• There has been a dramatic shift in the leading cause of blindness following economic development in Qatar
• In our study genetic diseases account for almost 80%
• Improved education, genetic counseling and screening programs8 may reduce the future incidence of genetically determined causes of blindness in Qatar
1. Hosni FA. Survey of major blinding conditions in Qatar. Ophthalmologica. 1977; 175(4):215-21.2. Vision for Children. A global overview of blindness, childhood and VISION2020: the right to sight.
World Health Organization (WHO) and the International Agency for the Prevention of Blindness (IAPB). www.v2020.org. Accessed April 2009.
3. Durnian JM, Cheeseman R, Kumar A, Raja V, Newman W, Chandna A. Eye. Childhood sight impairment: a 10-year picture. 2009 Feb 27.
4. Mudd SH, Levy HL, Kraus JP. Disorders of transsulfuration. In: Scriver CR, Beaudet AL, Sly WS, Valle D, editors. The Metabolic and Molecular Bases of Inherited Disease. New York: McGraw-Hill. 2001 p 2007-56.
5. El-Said MF, Badii R, Bessisso MS, Shahbek N, El-Ali MG, El-Marikhie M, El-Zyoid M, Salem MS, Bener A, Hoffmann GF, Zschocke J. A common mutation in the CBS gene explains a high incidence of homocystinuria in the Qatari population. Hum Mutat. 2006; 27(7):719.
6. Al-Gazali LI, Bener A, Abdulrazzaq YM, Micallef R, al-Khayat AI, Gaber T. Consanguineous marriages in the United Arab Emirates. J Biosoc Sci 1997; 29:491-7.
7. Bener A, Alali KA.Consanguineous marriage in a newly developed country: the Qatari population. J Biosoc Sci. 2006; 38(2):239-46.
8. Lindner M, Abdoh G, Fang-Hoffmann J, Shabeck N, Al-Sayrafi M, Al-Janahi M, Ho S, Abdelrahman MO, Ben-Omran T, Bener A, Schulze A, Al-Rifai H, Al-Thani G, Hoffmann GF. Implementation of extended neonatal screening and a metabolic unit in the State of Qatar: developing and optimizing strategies in cooperation with the Neonatal Screening Center in Heidelberg. J Inherit Metab Dis. 2007; 30(4):522-9.