title: Distribution and aetiology of blindness and visual impairment in mesoendemic onchocercal communities, Kaduna State, Nigeria. Kaduna Collaboration for Research on Onchocerciasis.
abstract: During a field trial of ivermectin in Kaduna State, 6831 people age 5 years and above, living in 34 mesoendemic onchocercal communities in Kaduna State, northern Nigeria, were examined for ocular disease. Visual function assessments included tests of visual acuity and visual fields. A total of 185 individuals (2.7%) were bilaterally blind by acuity criteria with a further 28 blind by field constriction. The overall prevalence of blindness was 3.1%. A further 118 individuals were visually impaired by WHO criteria. Examination for the cause of blindness revealed that 43% of eyes in bilaterally blind patients were blind due to onchocerciasis. A further 11% were blind from optic atrophy much of which was probably onchocercal in origin. Glaucoma was the next most common cause of blindness in the bilaterally blind (11%). Only 6% of eyes were blind from cataract as the primary cause. In the visually impaired population cataract was the most common primary cause of impaired/blind eyes (31%), followed by onchocerciasis (19%) [corrected].
authors.affiliation: Department of Ophthalmology, Ahmadu Bello University Teaching Hospital, Kaduna, Nigeria.
authors.forename: A
authors.initials: A
authors.lastname: Abiose
authors.forename: I
authors.initials: I
authors.lastname: Murdoch
authors.forename: O
authors.initials: O
authors.lastname: Babalola
authors.forename: S
authors.initials: S
authors.lastname: Cousens
authors.forename: I
authors.initials: I
authors.lastname: Liman
authors.forename: J
authors.initials: J
authors.lastname: Onyema
authors.forename: J
authors.initials: J
authors.lastname: Evans
authors.forename: W
authors.initials: W
authors.lastname: Gregory
authors.forename: B
authors.initials: B
authors.lastname: Jones
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001766:Blindness / Q000453:epidemiology* / Q000209:etiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005901:Glaucoma / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009549:Nigeria / Q000453:epidemiology; D015827:Onchocerciasis, Ocular / Q000150:complications / Q000453:epidemiology*; D009896:Optic Atrophy / Q000453:epidemiology; D015995:Prevalence; D014141:Trachoma / Q000453:epidemiology; D014786:Vision Disorders / Q000453:epidemiology* / Q000209:etiology; D014792:Visual Acuity