Prevalence and causes of severe visual impairment and blindness among children in the lorestan province of iran, using the key informant method

Razavi H, Kuper H, Rezvan F, Amelie K, Mahboobi-Pur H, Oladi MR, Muhit M, Hashemi H.

Ophthalmic Epidemiol. 2010 Mar;17(2):95-102.

Abstract

PURPOSE: To estimate the prevalence and causes of severe visual impairment and blindness among children in Lorestan province of Iran, and to assess the feasibility of the Key Informant Method in this setting.

METHODS: Potential cases were identified using the Key Informant Method, in 3 counties of Lorestan province during June through August 2008, and referred for examination. Causes of severe visual impairment/blindness were determined and categorized using standard World Health Organization methods.

RESULTS: Of 123 children referred for examination, 27 children were confirmed to have severe visual impairment/blindness or blindness. The median age was11 years (interquartile range 6-13), and 59% were girls. After adjusting for non-attenders, the estimated prevalence of severe visual impairment/blindness was 0.04% (0.03-0.05). The main site of abnormality was retina (44%), followed by disorders of the whole eye (33%). The majority of causes had a hereditary etiology (70%), which was associated with a family history of blindness (P = 0.002). Potentially avoidable causes of severe visual impairment/blindness were found in 14 children (52%). Almost all children with severe visual impairment/blindness had a history of parental consanguinity (93%).

CONCLUSIONS: Our findings suggest a moderate prevalence of childhood blindness in the Lorestan province of Iran, a high proportion of which may be avoidable, given improved access to ophthalmic and genetic counselling services in rural areas. The Key Informant Method is feasible in Iran; future research is discussed.