Heavy metals remediation through bio-solidification: Potential application in environmental geotechnics.

Heavy metals are pervasive pollutants found in water, soil, and solid wastes. Bio-solidification offers an environmentally friendly approach to immobilize heavy metal ions using two types of bacteria: urease-producing bacteria (UPB) and phosphatase-producing bacteria (PPB). UPB, exemplified by Sporosarcina pasteurii, secretes urease to hydrolyze urea and generate CO32- ions, while PPB, like Bacillus subtilis, produces alkaline phosphatase to hydrolyze organophosphate monoester (ROP) and produce PO43- ions. These ions react with heavy metal ions, effectively reducing their concentration by forming insoluble carbonate or phosphate precipitates. The success of bio-solidification is influenced by various factors, including substrate concentration, temperature, pH, and bacterial density. Optimal operational conditions can significantly enhance the remediation performance of heavy metals. UPB and PPB hold great potential for remediating heavy metal pollution in diverse contaminated areas such as tailings ponds, electroplating sewage, and garbage incineration plants. In conclusion, harnessing the power of these microbial methods can provide effective solutions for remediating heavy metal-induced pollution across a range of environmental conditions.

Degradation of Typical Reverse Sand-Mudstone Interbedded Bank Slope Based on Multi-Source Field Experiments.

The bank slopes in the Three Gorges Reservoir area (TGRA) have experienced obvious deterioration under the action of the periodic fluctuations in the reservoir water level. Generally, laboratory tests have been used to reveal the evolution trend of the slope banks. However, this method has a certain degree of cross-scale problem, especially for the mechanical state in a complex environment. Therefore, in this study, we took the Yangjiaping bank slope in the TGRA as an example and proposed a comprehensive on-site detection method to further reveal the rock mass degradation phenomenon of this typical reverse sand-mudstone interbedded bank slope. Specifically, multi-scale laser scanning, cross-hole acoustic wave detection, and inclination measurements were performed to analyze the fractures, quality, and deformation of rocky banks. The results showed that the deterioration of the bank slope manifested as the expansion, deepening, and widening of the cracks, as well as the peeling off and loosening of rocky banks. Large-scale laser scanning revealed that the deterioration zone was deformed along large fracture zones and layers. Unlike limestone slopes, the intact sandstone underground might be degraded by changes in water. There are few inclinometers and no deformation or weak deformation, which requires long-term monitoring. The relevant research methods provide an important reference for determining the instability and failure trend of the reservoir bank slopes.

Perception of Patient Safety and the Reporting System Between Medical Staffs and Patients in China: A Cross-Sectional Online Study.

OBJECTIVE: This study aimed to understand the perception of patient safety and the reporting system in public in China, and make further recommendations for the optimization of the reporting system of patient safety. METHODS: The following data were collected through an online questionnaire from medical staffs and patients: recognition of patient safety, comments on patient participation, comments on spontaneous reports, attitudes toward the principles of spontaneous reports, and willingness to participate. This information was presented with frequency and percentage with 95% confidence intervals (CIs). Spearman rank correlation was used to evaluate the association of those data. RESULTS: A total of 27,493 valid questionnaires were collected in this study. The participants who knew patient safety very well, regarded patients as an essential part to enhance patient safety, viewed spontaneous reports helpful, agreed on the 3 principles of voluntariness, anonymity, and nonpunishment of the reporter, and were willing to participate in reporting were accounted for 39.2% (95% CI, 38.6%-39.8%), 31.2% (95% CI, 30.7%-31.8%), 25.2% (95% CI, 24.7%-25.7%), 24.0% (95% CI, 23.5%-24.5%), and 19.9% (95% CI, 19.4%-20.4%), respectively. A moderate positive correlation was observed between comments on spontaneous reports and attitudes toward the principles of spontaneous reports (medical staffs versus patients, rs = 0.452 versus rs = 0.439; both, P < 0.01), as well as comments on patient participation and comments on spontaneous reports (medical staffs versus patients, rs = 0.410 versus rs = 0.460; both, P < 0.01). CONCLUSIONS: The awareness of patient safety may influence the choices of the other questions subsequently and may affect their voluntariness for safety reports ultimately. Pertinent measures, such as publicity of the relevant concept, simplification of the reporting procedures, and promotion of incentive mechanisms, should be adopted to promote the optimization of the reporting system.

Development and preliminary verification of the evaluation system for clinical practice guidelines in China.

OBJECTIVE: Clinical practice guidelines can improve healthcare processes and patient outcomes; however, the quality of these guidelines varies greatly in China. The aim of this study was to construct a comprehensive instrument for the appraisal of clinical practice guidelines in China (AGREE-CHINA), and to validate its reliability as a tool for helping potential guideline users in assessing guideline quality. METHODS: First, an interdisciplinary working group was established for developing the methods. They also created a checklist as a tool according to the Appraisal of Guidelines, Research and Evaluation II (AGREE II) standards, considering the particularity of Chinese clinical practice. Next, the first draft of AGREE-China was developed by vote, modification, preliminary trial, and cross-verification. To ensure the objectivity, credibility, and reproducibility of the draft assessment, all of the checklists and standards were cross-reviewed fairly widely. Finally, AGREE-CHINA and AGREE II were used to assess the Chinese guidelines published in the past five years, and the results were compared. RESULTS: The presented AGREE-CHINA covered five main checkpoints (science and rigor, effectiveness and safety, economy, usability and feasibility, and conflicts of interest) with each point divided into several more specific checkpoints. Definitions and rationales for each main checkpoint appear in the Appendix. The quality ratings based on the total scores of AGREE-China and AGREE II were consistent (r = 0.508, P = 0.020). Compared with AGREE II, the study showed a higher level of interrater-reliability for AGREE-CHINA overall (ICC = 0.957, P < 0.001). The mean time required for AGREE-CHINA was less than that for AGREE II; this was approximately 30 minutes for every assessment. User satisfaction was generally high. CONCLUSIONS: This paper has presented the first edition of the AGREE-CHINA appraisal tool for clinical guidelines. It is quick and easy to use; it assesses and performs well in comparison to AGREE II. This first version of AGREE-CHINA will require further development and validation.

[Effect of wintergreen oil on in vitro transdermal permeation of osthole and geniposide].

The aim of this study was to investigate the transdermal penetration enhancement effect of wintergreen oil and its action mechanisms. The in vitro transdermal tests were carried out to study the transdermal penetration enhancement effect of wintergreen oil by using osthole and geniposide as the lipophilic and hydriphilic model drugs. Fourier-transform infrared spectroscopy was used to investigate the effect of wintergreen oil on the molecular structure of rat stratum corneum, and the scanning electron microscope was employed to observe the change of rat skin surface after treatment by the oil. The wintergreen oil at proper concentrations could effectively promote the transdermal permeation of osthole and geniposide, and exhibited better penetration-enhancing activity for the lipophilic osthole, close to the commonly used classical penetration enhancer azone. The infrared spectroscopy study and scanning electron microscope showed that wintergreen oil mainly acted on the stratum corneum lipids, reduced dense stratum corneum, and reduced the skin barrier function. Thus, the wintergreen oil could effectively facilitate the transdermal absorption of the lipophilic and hydrophilic drugs, resulting from the lowed skin barrier function.

[Prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Shuangcheng City of Heilongjiang Province: the China Nine-Province Survey].

OBJECTIVE: To investigate the prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Shuangcheng City of Heilongjiang Province, China. METHODS: It was a population-based cross-section study. Geographically defined cluster sampling was used in randomly selecting 5 841 individuals aged 50 years or above in 28 basic sample units in Shuangcheng City from September to December 2006. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated through village registers followed door-to-door visits.Eligible individuals were invited to receive visual acuity measurement and eye examination. Statistical analyses were performed using Stata/SE Statistical Software, release 9.0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity. RESULTS: Five thousands four hundreds and eighty-one individuals were enumerated and 5 047 persons were examined, the response rate was 92.08%. Based on the criteria of World Health Organization visual impairment classification in 1973, the prevalence of blindness and moderate and severe visual impairment defined as best corrected visual acuity was 1.72% (87/5 047) and 4.69% (237/5 047) respectively. The prevalence of blindness and moderate and severe visual impairment defined as presenting visual acuity was 1.90% (96/5 047) and 7.23% (365/5 047) respectively. The prevalence of blindness and moderate and severe visual impairment was higher in aged (trend χ(2)=674.44, P < 0.01), female (χ(2)=39.61, P < 0.01) and illiterate (trend χ(2)=142.82, P < 0.01) persons. Cataract (52.70%) was still the first leading cause of blindness and visual impairment. The percentage of the retinal diseases, including age-related macular degeneration, high myopic retinopathy and diabetic retinopathy was 11.31% among the eyes with blindness and moderate and severe visual impairment. Un-corrected refractive error(13.38%) also was the main cause of visual impairment. CONCLUSIONS: The prevalence of blindness and moderate and severe visual impairment in Shuangcheng City is relatively higher in China Nine Province Survey. Cataract, retinal diseases and un-corrected refractive error are the main causes of the blindness and moderate and severe visual impairment.

[Prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Yangxi County of Guangdong Province: the China Nine-Province Survey].

OBJECTIVE: To investigate the prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Yangxi County of Guangdong Province, China. METHODS: It was a population-based cross-section study.Geographically defined cluster sampling was used in randomly selecting 5 531 individuals aged 50 years or above in Yangxi County from September 2006 to January 2007. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated using village registers followed by door-to-door visits.Eligible individuals were invited to receive visual acuity measurement and eye examination.Statistical analyses were performed using Stata/SE Statistical Software, release 9.0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity. RESULTS: Five thousands five hundreds and thirty-one individuals were enumerated and 4 589 persons were examined, the response rate was 82.97%. Based on the criteria of World Health Organization visual impairment classification in 1973, the prevalence of blindness and moderate and severe visual impairment defined as best corrected visual acuity was 2.38% (109/4 589) and 9.44% (433/4 589) respectively. The prevalence of blindness and moderate and severe visual impairment defined as presenting visual acuity was 2.68% (123/4 589) and 18.15% (833/4 589) respectively. The prevalence of blindness and moderate and severe visual impairment was higher in aged (trend χ(2) = 1 239.34, P < 0.01) , female (χ(2) = 37.88, P < 0.01) and illiterate (trend χ(2) = 235.11, P < 0.01) persons. Cataract was the first leading cause of blindness and visual impairment. CONCLUSIONS: The prevalence of blindness and moderate and severe visual impairment is higher among older adults aged 50 years or above in Yangxi County. Cataract remains as the first leading cause of blindness and visual impairment.

[Prevalence and causes of blindness and moderate and severe visual impairment among adults aged 50 years or above in Yongchuan District of Chongqing City: the China Nine-Province survey].

OBJECTIVE: To investigate the prevalence and causes of blindness and moderate and severe visual impairment among adults aged 50 years or above in Yongchuan of Chongqing City, China. METHODS: It was a population-based cross-section study.Geographically defined cluster sampling was used in randomly selecting 5663 individuals aged ≥ 50 years in Yongchuan District. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated through village registers followed door-to-door visits.Eligible individuals were invited to receive visual acuity measurement and eye examination. Prevalence of blindness and moderate and severe visual impairment was calculated according to different age, gender or education. And the reasons of blindness were analyzed.Statistical analyses were performed using Stata/SE Statistical Software, release 9.0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity. RESULTS: Five thousands six hundreds and sixty-three individuals were enumerated and 5390 persons were examined, the response rate was 95.18%. Based on the criteria of World Health Organization visual impairment classification in 1973, the prevalence of blindness and moderate and severe visual impairment defined as best corrected visual acuity was 2.12% (114/5390) and 5.40% (291/5390) respectively. The prevalence of blindness and moderate and severe visual impairment defined as presenting visual acuity was 2.49% (134/5390) and 10.71% (577/5390) respectively. The prevalence of blindness and moderate and severe visual impairment was higher in aged (trend χ(2) = 951.32, P = 0.000) , female (χ(2) = 33.35, P = 0.000) and illiterate (trend χ(2) equals; 141.32, P = 0.000) persons. Cataract was still the first leading cause of blindness and visual impairment.Un-corrected refractive error also was the main cause of visual impairment. CONCLUSIONS: The prevalence of blindness and moderate and severe visual impairment is relatively higher among older adults aged 50 years or above in Yongchuan District. The first leading cause of blindness and visual impairment is still cataract.

[Prevalence and causes of blindness and moderate and severe visual impairment among adults aged 50 years or above in Longyao County of Hebei Province:the China Nine-Province survey].

OBJECTIVE: To investigate the prevalence and causes of blindness and moderate and severe visual impairment among adults aged ≥ 50 years in Longyao County, Hebei Province, China. METHODS: It was a population-based cross-section study.Geographically defined cluster sampling was used in randomly selecting 5527 individuals aged ≥ 50 years in Longyao County. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated through village registers followed door-to-door visits.Eligible individuals were invited to receive visual acuity measurement and eye examination. Prevalence of blindness and moderate and severe visual impairment was calculated according to different age, gender or education. And the reasons of blindness were analyzed.Statistical analyses were performed using Stata/SE Statistical Software, release 9.0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity. RESULTS: Five thousands five hundreds and twenty-seven individuals were enumerated and 5051 persons were examined, the response rate was 91.39%. Based on the criteria of World Health Organization visual impairment classification in 1973, the prevalence of blindness and moderate and severe visual impairment defined as best corrected visual acuity was 1.05% (53/5051) and 3.46% (175/5051) respectively. The prevalence of blindness and moderate and severe visual impairment defined as presenting visual acuity was 1.48% (75/5051) and 7.94% (401/5051) respectively. The prevalence of blindness and moderate and severe visual impairment was higher in aged (trend χ(2) = 897.27, P = 0.000) , female (χ(2) = 30.32, P = 0.000), illiterate (trend χ(2) = 83.20, P = 0.000) persons. Cataract was still the first leading cause of blindness. Un-corrected refractive error also was the main cause of visual impairment. CONCLUSIONS: The prevalence of blindness and moderate and severe visual impairment is relatively lower among China Nine Province Survey. The first leading cause of blindness and visual impairment is still cataract.

[Prevalence and causes of blindness and moderate and severe visual impairment among adults aged 50 years or above in Changji City of Xinjiang Uygur Autonomous Region: the China Nine-Province survey].

OBJECTIVE: To investigate the prevalence and causes of blindness and moderate and severe visual impairment among adults aged ≥ 50 years in Changji City of Xinjiang Uygur Autonomous Region, China. METHODS: It was a population-based cross-section study.Geographically defined cluster sampling was used in randomly selecting 5714 individuals aged ≥ 50 years in Changji City. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated through village registers followed door-to-door visits.Eligible individuals were invited to received visual acuity measurement and eye examination. Prevalence of blindness and moderate and severe visual impairment was calculated according to different age, gender or education. And the reasons of blindness were analyzed.Statistical analyses were performed using Stata/SE Statistical Software, release 9.0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity. RESULTS: Five thousands seven hundreds and fourteen individuals were enumerated and 5250 persons were examined, the response rate was 91.88%. Based on the criteria of World Health Organization visual impairment classification in 1973, the prevalence of blindness and moderate and severe visual impairment defined as best corrected visual acuity was 0.74% (39/5250) and 3.83% (201/5250) respectively. The prevalence of blindness and moderate and severe visual impairment defined as presenting visual acuity was 1.33% (70/5250) and 8.02% (421/5250) respectively. The prevalence of blindness and moderate and severe visual impairment was higher in aged (trend χ(2) = 617.06, P = 0.000) , illiterate (trend χ(2) = 222.35, P = 0.000) persons. Cataract and was the first leading cause of blindness and visual impairment, the retinal diseases, including age-related macular degeneration, high myopic retinopathy, and diabetic retinopathy, were the second cause of blindness and visual impairment.Un-corrected refractive error was also the important cause of the visual blindness. CONCLUSIONS: The prevalence of blindness and moderate and severe visual impairment is not high among older adults aged ≥ 50 years in Changji City. The first main causes of blindness and visual impairment includes cataract, retinal diseases and un-corrected refractive error.

[Prevalence and causes of blindness and moderate and severe visual impairment among adults aged 50 years or above in Luxi County of Yunnan Province: the China Nine-Province survey].

OBJECTIVE: To investigate the prevalence and causes of blindness and moderate and severe visual impairment among adults aged ≥ 50 years in Luxi County of Yunnan Province, China. METHODS: It was a population-based cross-section study. Geographically defined cluster sampling was used in randomly selecting 5575 individuals aged ≥ 50 years in Luxi County. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated through village registers followed door-to-door visits.Eligible individuals were invited to receive visual acuity measurement and eye examination. Prevalence of blindness and moderate and severe visual impairment was calculated according to different age, gender or education. And the reasons of blindness were analyzed.Statistical analyses were performed using Stata/SE Statistical Software, release 9.0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity. RESULTS: Five thousands five hundreds and seventy-five individuals were enumerated and 5151 persons were examined, the response rate was 92.39%. Based on the criteria of World Health Organization visual impairment classification in 1973, the prevalence of blindness and moderate and severe visual impairment defined as best corrected visual acuity was 4.95% (255/5151) and 9.51% (490/5151) , respectively. The prevalence of blindness and moderate and severe visual impairment defined as presenting visual acuity was 5.40% (278/5151) and 15.84% (816/5151) , respectively. The prevalence of blindness and moderate and severe visual impairment was higher in aged (χ(2) = 1349.21, P = 0.000) , illiterate (χ(2) = 203.55, P = 0.000) persons. Cataract was still the first leading cause of blindness and visual impairment. CONCLUSIONS: The prevalence of blindness and moderate and severe visual impairment is highest in China Nine-Province Survey among older adults aged ≥ 50 years in Luxi County. The first leading cause of blindness and visual impairment is still cataract.

[Prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Ji'an county of Jiangxi province:the China Nine-Province Survey].

OBJECTIVE: To investigate the prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Ji'an county of Jiangxi province, China. METHODS: It was a population-based cross-section study. Geographically defined cluster sampling was used in 5402 randomly selected individuals aged ≥ 50 years in 28 clusters in Ji'an from September to November 2006. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated through village registers followed door-to-door visits. Eligible individuals were invited to receive visual acuity measurement and eye examination. Statistical analyses were performed using Stata/SE Statistical Software, release 9.0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity. RESULTS: Five thousands four hundreds and two individuals were enumerated and 5010 persons were examined, the response rate was 92.74%. Based on the criteria of World Health Organization visual impairment classification in 1973, 78 persons were diagnosed as blindness, 265 persons were diagnosed as moderate and severe visual impairment defined as best corrected visual acuity, the prevalence of blindness and moderate and severe visual impairment were 1.56% and 5.29% respectively. Ninety-four persons were diagnosed as blindness, 726 persons were diagnosed as moderate and severe visual impairment defined as presenting visual acuity, the prevalence of blindness and moderate and severe visual impairment defined as presenting visual acuity was 1.88% and 14.50% respectively. The prevalence of blindness and moderate and severe visual impairment was higher in aged (trend χ(2) = 970.15, P = 0.000), female (χ(2) = 89.81, P = 0.000), and illiterate persons (trend χ(2) = 241.85, P = 0.000). Cataract was still the first leading cause of blindness and visual impairment, the retinal diseases was the second. Un-corrected refractive error also was the main cause of visual impairment. CONCLUSIONS: The prevalence of blindness and moderate and severe visual impairment was higher than other district in China. The first leading cause of blindness and visual impairment is still cataract.

[Prevalence of blindness and low vision among adults aged 50 years or above in Ji'an county of Jiangxi province: the China nine-province survey].

OBJECTIVE: To estimate the prevalence of cataract, the outcomes of cataract surgery, cataract surgical coverage rate, cataract blindness social burden rate in Ji'an county of Jiangxi province, China. METHODS: Cluster sampling was used in randomly selected 5010 individuals aged ≥ 50 years in Ji'an county of Jiangxi province. All individuals were received visual acuity and eye examination, including the evaluation of lens status and cataract surgical status by slit lamp biomicroscopy. Data bank was established by Epi-info Software. Statistical analyses were performed using Stata/SE Statistical Software, release 9.0 (Stata Corp, College Station, TX). Confidence intervals and P values (considered significance at the P < 0.05 level) for prevalence of cataract, cataract surgical coverage rate, cataract blindness social burden rate and outcomes of surgery were calculated with adjustment for clustering effects and stratification associated with the sampling design. RESULTS: In 5010 individuals, 1158 cases of cataract were found, the prevalence of cataract was 23.11% among adults aged 50 or above. The prevalence of cataract was higher in the aged, female (P < 0.01). In 99 eyes with cataract surgery, 50.51% and 5.05% of eyes were performed by the modern extra-capsular surgery and phacoemulsification respectively. The rate of intraocular lens implantation was 55.56%. Post-operative presenting and best corrected visual acuity equal to or more than 0.7 was 10.1% and 45.5% of operated eyes respectively. The main causes of the post-operated eyes with worse visual acuity were post-capsular opacity and refractive error. The cataract surgical coverage rate was 32.29%, and the cataract blindness social burden rate was 3.83%. The cataract surgical rate was lower and cataract blindness social burden rate was higher in the aged persons (P < 0.01). CONCLUSIONS: Cataract is the most common eye disease that may lead into blindness and severe visual impairment among older adults aged equal or more than 50 years. The cataract surgical coverage rate is not high but the cataract blindness social burden rate is heavy in Ji'an county. The rate of intraocular lens implantation need increase and the visual outcomes of the surgery should be further improved in the future.

[Prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in the Shunyi District of Beijing: the China Nine-Province Survey].

UNLABELLED: OBJECTIVE To assess the prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in the Shunyi district of Beijing,China. METHODS: It was a population-based cross-section study. Geographically defined cluster sampling was used in 5840 randomly selected individuals aged > or = 50 years in 28 clusters in the Shunyi district from April to August 2006. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated through village registers followed door-to-door visits. Eligible individuals were invited to receive visual acuity measurement and eye examination. Statistical analyses were performed using Stata/SE Statistical Software, release 9. 0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity. RESULTS: Five thousands eight hundreds and forty individuals were recruited and 5118 persons were examined,the response rate was 87.64%. Based on the criteria of World Health Organization visual impairment classification in 1973,57 persons were diagnosed as blindness, 160 persons were diagnosed as moderate and severe visual impairment defined as best corrected visual acuity, the prevalence of blindness and moderate and severe visual impairment were 1.11% and 3.12% respectively. Sixty-five persons were diagnosed as blindness, 428 persons were diagnosed as moderate and severe visual impairment defined as presenting visual acuity, the prevalence of blindness and moderate and severe visual impairment were 1.27% and 8. 36% respectively. The prevalence of blindness and moderate and severe visual impairment was higher in aged (trend Chi2 = 784.23, P = 0.000), female (Chi2 = 28.35, P = 0.000), and illiterate persons (trend Chi2 = 397.13, P = 0.000). Cataract was still the first leading cause of blindness and visual impairment, the retinal diseases was the second. Un-corrected refractive error also was the main cause of visual impairment. CONCLUSIONS: The prevalence of blindness and moderate and severe visual impairment has been decreasing among older adults aged 50 years or above in the Shunyi district since 1996. The first leading cause of blindness and visual impairment is still cataract.

[Prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Qidong City of Jiangsu Province: the China Nine-Province Survey].

OBJECTIVE: To estimate the prevalence of blindness and low vision among older adults aged > or = 50 years in Qidong City of Jiangsu Province, China, in 2006. METHODS: Cluster sampling was used in randomly selecting 5662 individuals aged > or = 50 years from September to December 2006 in 16 clusters in Qidong City. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated through village registers followed door-to-door visits. Eligible individuals were invited to receive visual acuity measurement and eye examination. Statistical analyses were performed using Stata/SE Statistical Software, release 9.0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity. RESULTS: Five thousands six hundreds and sixty-two individuals were recruited, the response rate was 90.80%. Based on the criteria of World Health Organization visual impairment classification in 1973,91 persons were diagnosed as blindness, 175 persons were diagnosed as moderate and severe visual impairment defined as best corrected visual acuity, the prevalence of blindness and moderate and severe visual impairment were 1.77% and 3.40% respectively. One hundred and thirteen persons were diagnosed as blindness, 354 persons were diagnosed as moderate and severe visual impairment defined as presenting visual acuity, the prevalence of blindness and moderate and severe visual impairment were 2.20% and 6.89% respectively. The prevalence of blindness and moderate and sever visual impairment was higher in aged (trend Chi2 = 825.16, P = 0.000), female (Chi2 = 19.85, P = 0.001), and illiterate persons (trend Chi2 = 329. 85, P = 0.000). The leading cause of blindness was cataract. CONCLUSIONS: Blindness and low vision are associated with older age and illiterates in Qidong City. According to presenting visual acuity, the causes leading to blindness and low vision are, in descending order, cataract, ocular fundus disease, refractive error and cornea disease.

[Prevalence and surgery status of cataract among adults aged 50 years or above in the Shunyi district of Beijing: the China Nine-Province Survey].

OBJECTIVE: To assess the prevalence of cataract, the outcomes of cataract surgery, the rate of cataract surgical coverage, and the rate of cataract blindness social burden. METHODS: Cluster sampling was used in 5118 randomly selected individuals aged > or = 50 years in the Shunyi district of Beijing from April to August 2006. All individuals were received visual acuity and eye examination, including the evaluation of lens status and cataract surgical status by slit lamp biomicroscopy. Data bank was established by Epi-info Software. Statistical analyses were performed using Stata/SE Statistical Software, release 9.0 (Stata Corp, College Station,TX). Multiple logistic regression analysis was employed to analyzed the prevalence of cataract,cataract surgical coverage rate,cataract blindness social burden rate and outcomes of surgery among different ages, sex and educational background. RESULTS: In 5118 individuals, 797 cases of cataract were found, the prevalence of cataract was 15.57% among adults aged 50 or above. The prevalence of cataract was higher in the aged, female, illiterate persons (P < 0.01). In 189 eyes with cataract surgery, 65.08% and 23.28% of eyes were performed by the modern extra-capsular surgery and Phacoemulsification respectively. The rate of intraocular lens implantation was 89.42%. Post-operative presenting and best corrected visual acuity more than 0.7 was 30.16% and 61.38% of operated eyes respectively. The main causes of the post-operated eyes with worse visual acuity were post-capsular opacity and refractive error. The cataract surgical coverage rate was 62.22%, and the cataract blindness social burden rate was 2.64%. The cataract surgical rate was lower and cataract blindness social burden rate was higher in the aged persons (P < 0.01). CONCLUSIONS: Cataract is the most common eye disease that may lead into blindness and severe visual impairment among older adults aged equal or more than 50 years. The cataract surgical coverage rate is high in the Shunyi district, but still is lower in the aged persons. The visual outcomes of the surgery should be further improved in the future.

[Prevalence and surgery status of cataract among adults aged 50 years or above in Qidong City of Jiangsu Province: the China Nine-Province Survey].

OBJECTIVE: To estimate the prevalence of cataract, the rate of cataract surgical coverage rate,and the rate of cataract-blindness social burden among older adults aged 50 years or above in Qidong City of Jiangsu Province, China, in 2006. METHODS: Cluster sampling was used in randomly selected 5662 individuals aged 50 years or above in 16 clusters in Qidong City. 5141 individuals received visual acuity and eye examination from September to December 2006. Lens and cataract operation status were evaluated by slit lamp. Multiple logistic regression analysis was employed to analyzed the prevalence of cataract, cataract surgical coverage rate, cataract blindness social burden rate and outcomes of surgery among different ages, sex and educational background. RESULTS: In 5141 individuals, 1098 cases of cataract were found, the prevalence of cataract was 21.35% among adults aged 50 or above. The prevalence of cataract was higher in the aged, female, illiterate persons (P < 0.01). In 89 eyes with cataract surgery, 25.84% and 42.70% of eyes were performed by the modern extra-capsular surgery and Phacoemulsification respectively. The rate of intraocular lens implantation was 69. 66%. Post-operative presenting and best corrected visual acuity more than 0.7 was 24.70% and 48.31% of operated eyes respectively. The main causes of the post-operated eyes with worse visual acuity were retinal disorders post-capsular opacity and glaucoma. The cataract surgical coverage rate was 37.96%, and the cataract blindness social burden rate was 2.10%. The cataract blindness social burden rate was higher in the aged persons (P < 0.01). CONCLUSIONS: Cataract is the most common and important eye disease that may lead into blindness and severe visual impairment among older adults aged 50 years or above. The cataract surgical coverage rate is not so high in Qidong City, and even lower in the aged persons. The first important task in blindness prevention still is the elimination of cataract blindness. The visual outcomes of the cataract surgery should be further improved in the future.

[Sampling and measurement methods of the protocol design of the China Nine-Province Survey for blindness, visual impairment and cataract surgery].

OBJECTIVE: To design the protocol of the China nine-province survey for blindness, visual impairment and cataract surgery to evaluate the prevalence and main causes of blindness and visual impairment, and the prevalence and outcomes of the cataract surgery. METHODS: The protocol design was began after accepting the task for the national survey for blindness, visual impairment and cataract surgery from the Department of Medicine, Ministry of Health, China, in November, 2005. The protocol in Beijing Shunyi Eye Study in 1996 and Guangdong Doumen County Eye Study in 1997, both supported by World Health Organization, was taken as the basis for the protocol design. The relative experts were invited to discuss and prove the draft protocol. An international advisor committee was established to examine and approve the draft protocol. Finally, the survey protocol was checked and approved by the Department of Medicine, Ministry of Health, China and Prevention Program of Blindness and Deafness, WHO. RESULTS: The survey protocol was designed according to the characteristics and the scale of the survey. The contents of the protocol included determination of target population and survey sites, calculation of the sample size, design of the random sampling, composition and organization of the survey teams, determination of the examinee, the flowchart of the field work, survey items and methods, diagnostic criteria of blindness and moderate and sever visual impairment, the measures of the quality control, the methods of the data management. CONCLUSION: The designed protocol became the standard and practical protocol for the survey to evaluate the prevalence and main causes of blindness and visual impairment, and the prevalence and outcomes of the cataract surgery.