Visual Impairment Prevalence, Causes, and Role of Healthcare Access: A Systematic Review and Meta-Analysis in Iran

Purpose. Healthcare access is one of the determinants of visual impairment (VI), as a public health problem. The objective of this study was to estimate VI prevalence, related causes, and its correlation with access to physicians in Iran. Methods: This systematic review and meta-analysis include observational studies published in Iran. PubMed, Web of Science, Scopus, Google Scholar, and local databases were systematically searched by using the MeSH headings. Data on the provincial distribution of physicians, as an index of access to healthcare, was retrieved. A random-effect meta-analysis was performed to assess. Results. Eight articles were included. The pooled prevalence of blindness, low vision, and VI was 0.80% (95% CI: 0.61-0.99%), 2.92% (95% CI: 2.40-3.44%), and 5.57% (95% CI: 4.71-6.43%). Refractive errors were the most common causes of VI based on PVA with the pooled prevalence of 54.6% (95% CI: 43.4-65.8%). Based on BCVA, we found that the pooled prevalence of cataracts was 37.4% (95% CI: 29.5-45.3%) as the most common cause of VI. The results of metaregression showed that the greater number of general practitioners (GPs) (P value=0.01) and pharmacists (P value=0.024) per population were associated with a lower prevalence of blindness. Conclusion. Some of the main causes of visual impairment in Iran are preventable. Access to healthcare services may lead to early diagnosis of preventable causes of VI. Further well-designed studies and national surveys should be conducted to provide accurate data from different regions of Iran.