Impact of a 10-Year eye care program in sokoto, Nigeria: Changing pattern of prevalence and causes of blindness and visual impairment
Nasiru Muhammad1, Mohammed D Adamu1, Caleb Mpyet2, Catey Bounce3, Nuhu M Maishanu4, Aliyu M Jabo5, Muhammad M Rabiu6, Covadonga Bascaran7, Sunday Isiyaku8, Allen Foster7
1 Department of Ophthalmology, Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria
2 Department of Ophthalmology, University of Jos, Jos; Sightsavers Nigeria Office, Kaduna, Nigeria; Division of Ophthalmology, Kilimanjaro Centre for Community Ophthalmology International, University of Cape Town, Cape Town, South Africa
3 Department of Primary Care and Public Health Sciences, King's College, London, United Kingdom
4 Sokoto State Eye Health Programme, Ministry of Health, Sokoto, Nigeria
5 Helen Keller International, Abuja, Nigeria
6 Noor Dubai Foundation, Dubai, UAE
7 Clinical Research Department, International Centre for Eye Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
8 Sightsavers Nigeria Office, Kaduna, Nigeria
Dr. Nasiru Muhammad
Department of Ophthalmology, Usmanu Danfodiyo University Teaching Hospital, Sokoto
Source of Support: None, Conflict of Interest: None
BACKGROUND: This study was undertaken to ascertain the current magnitude and causes of blindness and visual impairment in persons aged 50 years and over and to assess the impact of a 10-year eye care program in Sokoto State, Nigeria.
METHODS: A rapid assessment of avoidable blindness (RAAB) survey (in persons 50 years and over) was conducted in 2016. Participants were selected in Wurno health zone using a two-stage cluster randomized sampling with probability proportional to size. Operational definitions were based on RAAB and World Health Organization eye examination record definitions. Eye care program documents were reviewed and data from a baseline survey undertaken in 2005 were reanalyzed.
RESULTS: A response of 89.1% (2405 of 2700 participants) was obtained in the 2016 survey. With available correction, the unadjusted prevalence of blindness was 7.7% (95% confidence interval [CI]: 6.4, 8.9). The odds of blindness were 1.8 times higher in females than males (95% CI: 1.3, 2.4;P< 0.001). Major causes of blindness were cataract (48.9%) corneal disease (20.1%), glaucoma (10.3%), and uncorrected refractive error/aphakia (8.7%). The age- and sex-adjusted prevalence of blindness has declined from 11.6% (95% CI: 7.4, 17.0) in 2005 to 6.8% (95% CI: 5.6, 8.0%) in 2016.
CONCLUSION: The blindness prevalence is high, and the major causes are avoidable in the health zone. The findings suggest that investments in the program over the last 10 years might have led to almost a halving in the prevalence of blindness in th e population. However, the small sample size of persons 50+ years from Wurno zone in the 2005 survey necessitate caution when comparing the 2005 and the 2016 surveys.