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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.

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Extracción de Catarata/estadística & datos numéricos , Catarata/epidemiología , Anciano , Ceguera/epidemiología , China/epidemiología , Estudios Transversales , Femenino , Humanos , Masculino , Prevalencia , Tibet/epidemiología , Baja Visión/epidemiología

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INTRODUCTION: The only population-based survey of blindness and visual impairment of a Tibetan population was conducted in the Tibet Autonomous Region in 1999. METHODS AND ANALYSIS: The Rapid Assessment of Avoidable Blindness methodology was used to conduct a survey of Kandze Tibetan Autonomous Prefecture, Sichuan Province of China in the Fall 2017. Using the 2010 census, 100 clusters of 50 participants aged 50 years or older were randomly sampled using probability proportionate to size. RESULTS: Among the 5000 people enumerated, 4763 were examined (95.3% response). The age-adjusted and sex-adjusted prevalence of blindness, severe visual impairment, moderate visual impairment and early visual impairment (EVI) were 1.6% (95% CI: 1.08 to 2.38)), 0.9% (95% CI:0.7 to 1.5), 5.1% (95% CI:4.4 to 5.7), and 7.45% (95% CI:6.67 to 8.2), respectively. The prevalence of blindness among Tibetans was significantly higher than that among Han Chinese (2.2% (95% CI:1.8 to 2.6) and 0.6 (95% CI:0.2 to 1.7), respectively, p<0.05). Women bore a significant excess burden of EVI compared with men (8.5% (95% CI:7.5 to 9.6) and 6.1% (95% CI:5.1 to 7.2), respectively, p<0.05). Cataract was the primary cause of blindness (39.4%) followed by macular degeneration (10.6%) and corneal opacity (5.3%). CONCLUSION: Blindness and visual impairment in Kandze Tibetan Autonomous Prefecture is substantially less than an earlier study of a Tibetan region and now resembles other regions of China. About 58% of blindness and 67% of SVIwere avoidable, primarily by providing cataract services. Eighty-three percent of EVI was avoidable by providing refractice services throughout the region.

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OBJECTIVE: To compare the bacterial profiles in conjunctival sac of dry eyes and normal eyes in Yi people aged 40 years or old. METHODS: A cross-sectional survey was conducted with standardized training and protocol. A total of 140 dry eyes of 70 individuals from Yi people in Jiulong county underwent ophthalmological examinations. The secretions of the inferior palpebral conjunctival sac were embrocated and inoculated on blood plates for 48 hours. The bacteria were separated and identified. Another 132 normal eyes from 66 Yi individuals were examined as controls. RESULTS: Bacterial positive cultivations were found in 72.1% (101/140) of dry eyes and 67.4% (89/132) of normal eyes, respectively. The difference was not statistically significant (P = 0.397). No gender difference in the bacterial positive rates was found either. Gram-positive bacteria were the main bacteria in both dry eyes (95.2%, 98/103) and normal eyes (91.1%, 82/90), predominantly staphylococcus epidemids and corynebacterium. There were no statistical differences in the constituents of bacteria in Gram classification and numbers of bacteria between dry eyes and normal eyes (P > 0.05). CONCLUSION: The bacterial profile in conjunctival sac of dry eyes is similar to that of normal eyes in Yi people aged 40 years or over. Gram-positive bacteria are the main bacteria.

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Conjuntiva/microbiología , Síndromes de Ojo Seco/microbiología , Bacterias Grampositivas/aislamiento & purificación , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , China/etnología , Corynebacterium/aislamiento & purificación , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Staphylococcus epidermidis/aislamiento & purificación

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AIM: To compare the bacterial flora in palpebral conjunctiva of xerophthalmia seniors of Tibetan, Yi and Han, and analyze the differences and similarities of the bacteria. METHODS: The test subjects were selected from 2 Tibetan, 2 Yi and 3 Han populated places, respectively. Total 222 seniors (444 eyes) with dry eye were examined. Secretion was collected from the palpebral conjunctiva of the subjects and then inoculated onto a blood agar plate. After 48h of incubation, the bacteria were examined for the differences and similarities between different ethnics. RESULTS: There was no significant difference (P>0.05) of Gram stain characterization, dominant bacteria and number of the bacterial species present in oxrophthalmia patients among Tibetan, Yi and Han nationalities. The bacteria presented in all groups include staphylococcus epidermidis, corynebacterium, micrococcus luteu, intracellular bacteria sphingomonas, pseudomonas aeruginosa. The bacteria detected from the two of three ethnic groups were staphylococcus aureus, staphylococcus haemolyticus, escherichia coli, kytococcus sedentarius, streptococcus angina, micrococcus lylae, and staphylococcus heads. The incidence rate of bacteria-associated dry eye in Tibetan population was significantly lower than that of Han and Yi population. CONCLUSION: There is no significant difference in the bacteria flora of palpebral conjunctiva observed among dry eye elder populations of Tibetan, Yi and Han people. All of staphylococcus epidermidis, corynebacterium, micrococcus luteu, intracellular bacteria sphingomonas, pseudomonas aeruginosa, staphylococcus aureus, staphylococcus haemolyticus, escherichia coli, kytococcus sedentarius, streptococcus angina, micrococcus lylae and staphylococcus heads are common bacteria flora of the three nationalities inhibiting in this area.