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Or iginal s tud y RAAB in Zimbabwe
Vol 16 | No 2 • Autumn 2021 SA Ophthalmology Journal
Rapid assessment of avoidable blindness in Masvingo Province, Zimbabwe: considerations for resource-limited settings D Minnies, NDMT Clin Path, NHDMT, MPH, PhD (Public Health); Director: Community Eye Health Institute, Division of Ophthalmology, University of Cape Town, South Africa ORCID: https://orcid.org/0000-0002-9173-782X B Macheka, MBChB, MMed(Ophth); Lead Government Ophthalmologist, Ministry of Health and Child Care, Zimbabwe J Joseph, MBChB, MMed(Ophth), Provincial Ophthalmologist, Masvingo Province, Ministry of Health, Zimbabwe C Cook, MBChB, DO, MPH, FRCOphth SA; Emeritus Professor, Division of Ophthalmology, University of Cape Town, South Africa ORCID: https://orcid.org/0000-0001-5661-7390 Corresponding author: Dr Deon Minnies, H53 Old Main Building, Groote Schuur Hospital, Observatory 7925, South Africa; tel: +27 21406 6039; email: d.minnies@uct.ac.za
Abstract Background: A rapid assessment of avoidable blindness was conducted to assess the situation of blindness and visual impairment in Masvingo Province, Zimbabwe, using the standard rapid assessment of avoidable blindness (RAAB) methodology. Methods: A sample size of 3 756 was calculated by RAAB software, using an estimated prevalence of blindness of 3.0%±0.7% with 95% confidence interval based on previous RAAB findings in the region. The sampling was done using multistage systematic cluster random sampling, with 76 clusters of 50 people aged 50 years or above selected with probability proportional to size (PPS). A total of 3 795 people were examined, representing a response rate of 99.9%. Examination procedures included measurement of visual acuity (VA) with available correction and pinhole correction, assessment of lens status and examination of the fundus with a direct ophthalmoscope. Data was collected using the RAAB smartphone application. Results: The sample prevalence of bilateral blindness with available correction (presenting VA <3/60) in the better eye was 3.6% (95% confidence interval: 2.9–4.2). Untreated cataract (65.2%) was the most common cause of blindness followed by
Introduction
The Vision Loss Expert Group reported that, in 2015, the prevalence of blindness was 36 million globally,1 and that a further 216.6 million people were moderately to severely visual impaired, making a total of 253 million people with vision loss.2 The World Health Organization (WHO) defines blindness as ‘presenting visual acuity worse
glaucoma (16.3%) and non-trachomatous corneal opacity (10.4%). Just over half (52.2%) of people blind due to cataract (presenting VA <3/60) had undergone surgery. Of the eyes operated for cataract, 59.7% could see 6/18 or better (‘Good outcome’) while 25.7% could not see 6/60 (‘Poor outcome’) with available correction. Conclusion: There is a need to further strengthen the capacity of the Masvingo provincial eye care programme through effective planning, monitoring and management of eye care services to meet high performance targets, nationally and globally. Keywords: rapid assessment of avoidable blindness, blindness, visual impairment, Zimbabwe Funding: The source of the funding is from a grant from Christian Blind Mission (CBM), as part of a project being implemented by Zimbabwe Council for the Blind. Conflict of interest: The authors declare they have no conflicts of interest with regard to this study.
than 3/60’; severe visual impairment as ‘presenting visual acuity worse than 6/60 but better than 3/60’; moderate visual impairment as ‘presenting visual acuity worse than 6/18 but better than 6/60’ and functional low vision as incurable presenting visual acuity worse than 6/18 but with light perception, all in the better eye. 3 Almost 90% of people affected by
blindness or visual impairment live in low- and middle-income countries, and more than 75% of visual impairment is avoidable.4 About half of the 47 countries in sub-Saharan Africa whose data contributed to the Vision Atlas had population surveys done, and 36% of countries had a national blindness prevention committee/national eye care strategy in place.4
