Prevalence and Causes of Blindness and Vision Impairment in the State of Qatar - Results of a Population-based Cross-Sectional Study.

Introduction: A population-based survey of the prevalence and causes of blindness and vision impairment among people 50 years and older living in the State of Qatar.

Methods: A Rapid Assessment of Avoidable Blindness (RAAB) methodology, applied from May 2022 to June 2023, utilized stratified two-stage cluster random sampling to select 5060 persons 50 years and older resident in Qatar from 145 communities chosen by probability proportional to size. Communities were stratified by Qatari and non-Qatari nationality. Participants were examined by ophthalmologists in primary health centers.

Results: Of the 3206 participants examined, 14 (0.4%) were blind and 10 (0.3%) had severe vision impairment. Compared to a previous RAAB study in 2009, the prevalence of blindness (presenting visual acuity [VA] <3/60), decreased from 1.28% to 0.4% (95%CI 0.2-0.7%). The age-sex adjusted prevalence of all vision impairment (presenting VA <6/12-NPL) was 9.7% (95%CI 8.3-11.1), higher among females 12.6% (95%CI 10.5-14.6), and Qataris 16.7% (95%CI 14.4-19.1), compared to males 7.6% (95%CI 6.3-9.0), and non-Qataris 6.3% (95%CI 5.1-7.5). The principal causes of blindness included diabetic retinopathy (33.3%), cataract (20%), glaucoma (13%), and other posterior segment diseases (13%). All vision impairment was mainly attributed to uncorrected refractive errors at 58% and cataract at 17%, with the former being more common among non-Qataris and cataract more prevalent among Qataris.

Conclusion: Our findings show a low prevalence of vision impairment compared with many countries that have published vision impairment data. Vision impairment was mainly caused by diabetic retinopathy, cataract, and uncorrected refractive error. Further reduction in vision loss can be achieved with early detection and improved access using innovation and technology.