Prevalence and service assessment of cataract in Tibetan areas of Sichuan Province, China: population-based study

Abstract

ObjectivesTo assess the prevalence of visual impairment (VI) and blindness (BL) due to cataract and cataract surgical outcomes in remote dispersed and high-altitude Tibetan areas of China.Design and settingA cross-sectional study was conducted among people aged 50 and above in Tibetan Autonomous Prefecture of Kandze (TAPK), China, in 2017. The Rapid Assessment of Avoidable Blindness protocol was followed.ParticipantsOf 5000 eligible participants, 4764 were examined (response rate 95.3%).Primary and secondary outcome measuresCataract VI was defined as lens opacity at visual acuity (VA) levels of <3/60 (Blindness (BL)), ≥3/60 and <6/60 (severe visual impairment (SVI)), ≥6/60 and <6/18 (moderate visual impairment (MVI)), ≥6/18 and <6/12 (early visual impairment (EVI)).ResultsThe estimated prevalence of cataract BL was 0.61% (95% CI 0.42 to 0.87). With best corrected VA, the estimated prevalence of SVI from cataract was 0.86% (95% CI 0.63 to 1.17); MVI was 2.39% (95% CI 2.00 to 2.87) and EVI was 5.21% (95% CI 4.61 to 5.87). Women in TAPK had a significantly higher prevalence of cataract BL (0.82%, 95% CI 0.54 to 2.15) than men (0.34%, 95% CI 0.16 to 0.70). Women had lower cataract surgical coverage (CSC) by eyes (60.8%, 95% CI 55.5 to 65.8) compared with men (70.1%; 95% CI 63.7 to 75.7). The prevalence of cataract BL was higher among Tibetan (2.28%; 95% CI 1.98 to 2.62) than Han Chinese (1.01%%; 95% CI 0.54% to 1.87%). Overall CSC by person with BL (by better eye) was 82.0% (95% CI 75.2 to 87.6). Among cataract-operated participants, 71.2% had VA equal to or better than 6/18.ConclusionsThe study detected a low prevalence of VI and BL due to cataract with high CSC in the study area compared with many other places in China. Further actions should be taken to improve cataract surgical outcome.

Myopia prevalence and ocular biometry in children and adolescents at different altitudes: a cross-sectional study in Chongqing and Tibet, China

“…Kobashi et al 5 reported that there is a small amount of riboflavin in the human corneal stroma, and the ex vivo corneal stiffness significantly increases after VL (375 nm wavelength) irradiation based on physiological riboflavin. Epidemiological data show that the prevalence of keratoconus, pterygium, dry eye disease, cataract and strabismus is significantly higher in the highlands than in the lowlands2 6–9 and the cornea of the highlanders is thinner than that of the lowlanders 10 11. Our previous study also found that the prevalence of myopia among children and adolescents in Tibet was lower than that in the plains 12.…”

Retrospective analysis of cataract surgery outcomes in China from 2009 to 2018: from a national registry system data

“…Cataract remains the primary cause of blindness and visual impairment for people aged 50 years and older in China, constituting up to 35% of cases of blindness and 67.1% of cases of visual impairment, respectively. [17][18][19][20] The prevalence of cataract has decreased recently with the advancement of cataract surgical technology from suppliers and increased visual demand from patients. 1 The CSR per million people per year has been continuously improved in China, from about 83 in 1988 to 2205 in 2017, 21 an increase of nearly 27 times.…”

Cost-effectiveness and cost-utility of a digital technology-driven hierarchical healthcare screening pattern in China

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