AN UPDATE OF CAUSES OF CHILDHOOD BLINDNESS AND SEVERE VISUAL IMPAIRMENT IN CHILDREN ATTENDING SCHOOLS FOR THE BLIND IN BENIN CITY, NIGERIA.
Keywords:Childhood blindness, severe visual impairment, causes, blind schools, Benin City.
Aim: To determine the current causes of visual impairment and blindness amongst students in schools for the blind in Benin City, Nigeria.
Methods: A cross sectional survey of students attending all three schools for blind education in Benin City, Nigeria, was carried out in 2016. All consenting students comprised of two groups of students; those below 16 years and those 16 years and above, but who became blind before the age of 16 years were surveyed. Age, sex, educational status, cause, onset, and severity of visual impairment were assessed and the data collected was analyzed using the World Health Organization Prevention of Blindness Examination Record for Childhood Blindness (WHO/PBL ERCB).
Results: 13 students (44.8%) were less than 16 years and 16 (55.2%) were 16 years or older. Twenty –six children (89.7%) were blind and 3 (10.3%) had severe visual impairment. The major anatomical sites of blindness/ SVI were lens (9, 31.0%), whole globe (8, 27.6%) and cornea (5, 17.3%). At a disaggregated level, the causes of blindness/SVI were similar in both groups but corneal lesions occurred at a higher proportion in the older age group (13.8%) than the younger group (3.4%). The aetiology of blindness/ SVI was unknown in 18 (62.0%) cases. Measles keratopathy, ophthalmia neonatorium and harmful traditional practices were identified in a few students (5, 17.3% respectively). Majority of the cases of blindness/SVI were avoidable (22, 75.9%) and mostly treatable by surgery. Five (55.6 %) out of 9 students with lens- related causes had operated cataracts but 4 (80%) had poor outcome, mostly due to amblyopia from late surgery in addition to other post-operative complications.
Conclusion: Cataracts and glaucoma were the major causes of blindness and visual impairment in this study. Consequently, there is a need for increasing awareness about childhood blindness and early therapeutic interventions in susceptible child populations.