Review of the publications of the Nigeria national blindness survey: Methodology, prevalence, causes of blindness and visual impairment and outcome of cataract surgery

Abstract

This is a review of the major publications from the Nigeria national blindness survey in order to highlight major findings and challenges of eye care in Nigeria. The review summarizes methodology and key findings. Survey publications on methodology, prevalence and causes of visual impairment and outcome of cataract surgery were retrieved, reviewed and relevant data extracted, reported and discussed. The study was the largest and more detailed eye survey in Nigeria (15,375 people 40 years and older recruited). Participants had detailed eye examination including visual acuity, autorefractokeratometry, A-scan biometry, visual field and basic eye examination. Cause(s) of visual impairment in each eye using WHO algorithm was determined among participants with vision < 6/12. Some of the participants also had qualitative questions on barriers to uptake of services, quality of life and visual function. Major highlights of the results as contained in the publications include a high prevalence of blindness with 4.2% (95% CI: 3.8-4.6%;),of the study population having blindness (using presenting vision (PVA)) even with best correction the prevalence was 3.4% (95% CI: 3.0-3.8%. The prevalence of SVI using PVA was 1.5% (95% CI: 1.3-1.7%).and with best correction 0.8% (95% CI: 0.7-1.0%). Blindness varied by age groups, sex, literacy level and geopolitical zone. Furthermore, 84% of blindness was due to avoidable causes with cataract responsible for 43% of blindness, glaucoma 16.7%, uncorrected aphakia 8.4% and corneal opacity 7.9%. Of the total 538 eyes that had cataract surgery procedures, 42.7% had couching and the remaining had cataract surgery, but only 41.4% of cataract operated eyes had IOL surgery. Outcome of cataract surgery was good at presentation for only 30.8% of eyes (84 eyes) which improved to 56.8% with correction. The possible remedy for the high burden of needless blindness and harmful eye health practices in Nigeria are discussed.

High-Fidelity Cataract Surgery Simulation and Third World Blindness

“…It has been reported that nearly half of all cataract operations in China result in blindness. 4 Almost half of all cataract operations in Nigeria entail the centuries-old technique of “couching.” 5 Couching is a primitive and unsterile technique whereby a probe is introduced into the eye and into the cataractous lens in an attempt to dislodge it from its natural position and into the vitreous cavity. Postprocedural success is judged by the patient’s ability to see light again.…”

Aphakia Correction by Injection of Foldable Intra Ocular Lens in the Anterior Chamber

“…Uncorrected unilateral aphakia is one of the leading causes of monocular visual impairment in some African countries 1,2. Aphakic glasses, contact lenses, and intraocular lens (IOL) have been proposed as methods of visual rehabilitation after cataract surgery.…”

Direct non-medical costs double the total direct costs to patients undergoing cataract surgery in Zamfara state, Northern Nigeria: a case series

“…Cataract is responsible for blindness in more than 20 million people [ 1 ] and may reach 50 million by 2020 [ 2 ]. In Nigeria cataract is the leading cause of blindness (43%), affecting an estimated 400,000 adults [ 3 ] which is projected to reach over 570,000 by 2020 [ 4 ]. However, in 2008 the cataract surgical rate (CSR) in Nigeria was only 300/million population/year, significantly below that recommended for Africa i.e.…”