Visual Outcomes of Cataract Surgery among Nigerian Adults: A Systematic Review of Recent Hospital-based Surveys

Purpose: This study aimed to determine the proportion of good, borderline, and poor visual outcomes of cataract surgery among adult Nigerians and to identify factors associated with borderline/poor outcomes. Methods: This is a systematic review of all primary hospital-based studies published between 2007 and 2023, reporting visual outcomes of cataract surgery among adult Nigerians using the World Health Organization (WHO) criteria. Google Scholar, ResearchGate, Semantic Scholar, and PubMed Medline databases were searched for eligible studies between January and March 2024. The quality of the included studies and risk of bias were assessed using the appraisal tool for cross-sectional studies. The causes and factors associated with borderline/poor outcomes were identified. Results were extracted and summarized using descriptive statistics. Results: Data were drawn from nine independent studies, comprising a total of 1796 cataract-operated eyes among patients aged between 16 and 100 years. The proportion of visual outcomes within 4–8 weeks of post-surgery ranged from 37.8% to 94.5% for good, 3.3–50.7% for borderline, and 1.0–17.0% for poor. On average, proportions were 69.3% for good, 23.6% for borderline, and 7.1% for poor. Following the best correction, the proportions improved to 82.6%, 10.9%, and 6.5% for good, borderline, and poor, respectively. The major factors associated with borderline/poor outcomes were refractive error, largely due to a lack of routine biometry, and coexisting ocular morbidities. Conclusion: This review found that visual outcomes of cataract surgery among adult Nigerians vary widely and mostly fall below WHO standards. This highlights the need for better access to biometry equipment and improved post-surgery refraction services in Nigeria.