Prevalence Of Visual Impairment And Blindness,Prevalence And Surgery Status Of Cataract In Rural Older Adults In Shandong Province

[Background] Blindness and severe visual impairment are high priority public health issues and cataract blindness is an uppermost cause for blindness worldwide. In1986, a population-based, cross-sectional study of visual impairment and blindness based on the best corrected visual acuity was performed in older adults in rural Shandong Province. But the status of cataract surgery was not reported in that study. In the past20years, with the degree of the aged phenomenon becoming more serious and the development of socioeconomic status and medical insurance level in Shandong province, the prevalence of blindness and visual impairment had changed dramatically. In addition, the world health organization had proposed the concept of Presenting Visual Acuity (PVA) and redefined blindness and visual impairment on basis of PVA. In order to acquire the latest prevalence and causes of visual impairment and blindness, the prevalence of cataract and outcomes of cataract surgery in rural area in Shandong Province, a Population-based study is needed urgently.[Objective] To investigate the prevalence and causes of visual impairment and blindness, the prevalence of cataract and the status of cataract surgical among older adults aged50years or above in rural populations in Shandong Province.[Methods] A population-based and cross-sectional study. A total of19,583people aged50years or above were randomly selected from four rural counties in Shandong Province. All eligible persons received visual acuity testing and comprehensive eye examination. Moreover, a structured questionnaire was acquired. Cataract and surgery status was diagnosed by ophthalmologists using slit-lamp biomicroscopy. The prevalence and causes of visual impairment and blindness, prevalence of cataract、intraocular lens implantation rate、cataract surgical coverage and the cataract-blindness social burden rate were main outcome measures. [Results] The examination response rate is90.98%(17816/19583) in this study. According to the presenting visual acuity, the prevalence of blindness was1.58%and prevalence of moderate and severe visual impairment was7.01%. Similarly, according to best corrected visual acuity, the prevalence of blindness and moderate and severe visual impairment were1.33%and3.66%, respectively. The prevalence of cataract blindness was0.94%for presenting visual acuity and0.86%for best-corrected visual acuity. In17,816individuals, there were4,938cases were diagnosed as cataract, the prevalence of cataract was27.72%. The prevalence of cataract was higher in older people, female, illiterate persons (P<0.01). In310eyes with cataract surgery,62.58%and10.32%of eyes were performed by the modern extra-capsular surgery and phocoemusification, respectively. The rate of intraocular lens implantation was77.10%. The cataract surgical coverage rate was36.77%, and the cataract-blindness social burden rate was2.12%. The cataract-blindness social burden rate was higher in the aged persons and illiterate persons (P<0.05)[Conclusion] Visual impairment and blindness are still important public health problems in rural areas in Shandong Province. Cataract is the uppermost cause for severe visual impairment and blindness. The cataract surgical coverage is very lower in older adults aged50years or above. Surgery for cataract blindness is still the first important task in prevention of blindness in Shandong Province.