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

Danba Jiachu; Ling Jin; Feng Jiang; Li Luo; Hong Zheng; Duo Ji; Jing Yang; Nima Yongcuo; Wenyong Huang; Jinglin Yi; Tess Bright; Jennifer Ly Yip; Baixiang Xiao

doi:10.1136/bmjopen-2019-031337

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

BMJ Open. 2019 Nov 3;9(11):e031337. doi: 10.1136/bmjopen-2019-031337.

Authors

Danba Jiachu¹, Ling Jin², Feng Jiang¹, Li Luo¹, Hong Zheng¹, Duo Ji¹, Jing Yang¹, Nima Yongcuo¹, Wenyong Huang³, Jinglin Yi⁴, Tess Bright⁵, Jennifer Ly Yip⁶, Baixiang Xiao^{7

8}

Affiliations

¹ Kham Eye Centre, Kandze Prefecture People's Hospital, Kangding, China.
² Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
³ State Key Laboratory of Ophthalmology, Zhongshan Opthalmic Centre, Sun Yat-sen University, Guangzhou City, China.
⁴ Nanchang University Affiliated Eye Hospital, Nanchang University, Nanchang, China.
⁵ International Centre for Evidence in Disablility, London School of Hygiene & Tropical Medicine, London, UK.
⁶ International Centre for Evidence in Disablility, International Centre for Eye Health, London School of Hygiene and Tropical Medicine, London, UK.
⁷ State Key Laboratory of Ophthalmology, Zhongshan Opthalmic Centre, Sun Yat-sen University, Guangzhou City, China xiaobaixiang2006@126.com.
⁸ Nanchang University Affiliated Eye Hospital, Nanchang City, China.

Abstract

Objectives: To 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 setting: A 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.

Participants: Of 5000 eligible participants, 4764 were examined (response rate 95.3%).

Primary and secondary outcome measures: Cataract 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)).

Results: The 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.

Conclusions: The 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.

Keywords: cataract and refractive surgery; international health services; public health.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aged
Blindness / epidemiology
Cataract / epidemiology*
Cataract Extraction / statistics & numerical data*
China / epidemiology
Cross-Sectional Studies
Female
Humans
Male
Prevalence
Tibet / epidemiology
Vision, Low / epidemiology