Causes of Visual Impairment and Blindness Among children in schools for the Blind in Yemen

Khalid A. Al-Mohammadi1, Muhammad Babar Qureshi2, Lea Hyvärinen 3, Mahfouth A Bamashmus4*. 1Rehabilitation Centre for Hearing and Visually Impaired, Taiz, Republic of Yemen. 2CBM International, Cambridge, England.3Faculty of Rehabilitation Sciences, Finland. 4Eye Department, Faculty of Medicine and Health Sciences, Sana’a University, Republic of Yemen *Corresponding author: Dr. Mahfouth Bamashmus: email: bamashmus@hotmail.com

Abstract

Background: Childhood blindness is increasingly becoming a major challenge worldwide. It is
estimated that a child goes blind somewhere in the world every minute. Aim: To determine the causes
of visual impairment and blindness in children in schools for the Blind in Yemen. Methods: Children
attending 13 schools for the Blind in Yemen were examined during February and April 2009. A
modified WHO/PBL eye examination record for children with blindness and low vision was used to
categorize the anatomical and the etiological causes of visual loss. Data were analyzed by using the
EPI-INFO 2004 programme. Results: A total of 453 students less than or equal to 16 years of age were
examined in 13 schools for the Blind in 9 governorates of Yemen. Of the children examined, 120
(26.5%) were visually impaired (<3/9.5-≥ 3/60) and 288 (63.6%) were blind (<3/60-NLP). The major
anatomical sites of visual loss were whole globe (30.0%) mainly buphthalmos, retina (26.6%), optic
nerve (16.9%), lens (11.8%) and cornea (8.2%). The major etiology was hereditary in 50.0%,
undetermined in 35.5% and postnatal/childhood factors in 13.5%. Nearly half of cases (49.2%) were
considered to be potentially avoidable. The family history was positive in 229 (50.6%) and the
products of consanguineous marriages was found in 199 (43.9%). In 39 children (8.6%), additional
disabilities were present mainly mental retardation in 22 (4.9%). Conclusions: Hereditary diseases
are the predominant causes of childhood visual loss in Yemen. Consanguineous marriages were
highly observed in the parents of the children. The treatable conditions buphthalmos and cataract or
poorly treated cataracts were the important leading causes of visual loss. Information about the causes
of visual impairment and blindness is important for adequate provision of special services and for
developing preventive strategies.