The Epidemiology Of Ophthalmopathy About Adults Aged ≥50 Years In Yifeng County Of Jiangxi Province

Objective:To investigate the prevalence and major causes for blindness and low vision among population aged=50 years in Yi'feng county of Jiangxi province and to facilitate the formulation and implement of the regional project againsting blindness.Methods:Cluster randomly sampling was used in individuals aged =50 years in 29 villages in Yi'feng county of Jiangxi province during November,2007 to April,2008. 5,511 adults over 50 years old(male 2716,female 2795)were included.Prior to the formal examinations,the investigators received a 3-week period of training coursing to know about the purpose,methods and detailed procedures of the survey.They were familiarized with inspectoscopes,various types of tables and lists, the meanings,contents of various variables in the unified survey tables and the corresponding standards.The examination procedures were established after a pilot study was conducted.Each sampled adults were enumerated according to the registered permanent residence and recorded the results.The revised Table for ocular region Survey of national ophthalmopathy was used in the questionnaire,investigation and examination of the subjects.The collected data include:general information(county, sampling point,source of the information,nationality,name of the sampled adult, relationship between the sampled adult and the person who offer the information,age, sex,the background of education),visual check(presenting visual acuity(PVA),best corrected visual acuity(BCVA)),the history of cataract operation and dacryorrhea in the near past,ophthalmological examinations(the examinations of ophthalmic protomerite include blephara,bulbus oculi,conjunctiva,cornea,pupillary light reflex, condition of lens crystalline,history of other eye operation,detail of the cataract operation,examination of lacrimal passages,corporis vitre,fundus.and the cause of blindness and impairment of vision.The director of project who took the whole responsibility of the investigation supervised two investigative teams,each of which was directed by an ophthalmologist.The collected data was checked,verified and recorded by two appointed persons.Data entry was carried out daily,alongside the field work.The data entry was done twice to ensure accuracy.Data bank was established by using the EpiInfo 3.0 software and A comprehensive statistical analysis program was developed by Stata Statistical Software.Results:Among 5511 sampled adults,5054 individuals received the investigation. The examination rate was 91.71%.For the reasons of intellectual ability or epicophosis,there were 31 person who couldn't cooperate with the examiners were excluded.Together,5023 individuals were enumerated,the response rate was 91.14%.According to the WHO criteria of visual impairment/blindness(standard A) and best corrected visual acuity(BCVA),there are 118 people with bilateral blindness, the prevalence of bilateral blindness was 2.35%according to the population number, the reason of cataract account 61.40%of the number of blindness.The number of unilateral blindness is 282(5.61%),bilateral low vision is 118(2.35%)unilateral low vision is 208(4.14%).According to the WHO criteria and the univariate analysis,it shows that the prevalence of low vision and blindness was associated with age and gender(P＜0.001).It shows that the prevalence of low vision increased along with the increase of age,and the prevalence of female is higher than male.The odds rate(OR)of the prevalence of bilateral blindness between female and male is 1.92(95%Confidence intervals:1.30～2.85),and the difference is significant(p=0.0009),the OR of the adjusted age between female and male is 2.09(95%Confidence intervals:1.41～3.12) and the difference still be significant(p=0.0002).But the odds rate of the prevalence of unilateral blindness between female and male was 0.85(95%Confidence intervals: 0.66～1.08),the difference was not significant(p=0.1824),The odds rate was 0.90 (95%CI:0.70～1.15)after the age had been adjusted.The difference was not significant(P=0.3861＜1)also.According to the criteria of India and Nepal(standard B)and presenting visual acuity(PVA),the prevalence of severe bilateral blindness is 2.71%(136 case) according to the population number,and the prevalence of mild bilateral blindness is 0.98%,(49 case),the prevalence of unilateral blindness is 7.45%(374 case),and the prevalence of visual acuity impairment is 2.40%(623 case).The prevalence of blindness went up with the increase in the age of people,according to classification of visual impairment of the standard B(x2=19.08,p＜0.0001).The odds rate(OR)of the prevalence of blindness(both mild and severe) between female and male was 2.01(95%Confidence intervals:1.46～2.76),with a significant difference(p＜0.0001).The odds rate(OR)of the prevalence of blindness between female and male was 2.20(95%Confidence intervals:1.59～3.04)when the age had been adjusted,without a significant difference.Conclusion:The prevalence of bilateral blindness among adults aged=50 years in Yi'feng county of Jiangxi province is slight higher than the average level of our country,with cataract being the principle disease causing blindness.Compared to the national ophthalmopathy survey,some new differences exist regarding to the main causes for blindness.The prevalence of cataract is higher than the average level of our country.The situation of blindness in Yi'feng county is more serious than that of Shuen'yi county of Beijing,but the situation of visual impairment is less serious. These findings suggested that many difference exsit in the situation of blindness and visual impairment,varying with the different period and region,and the situation of blindness in Yi'feng county of Jiangxi province is serious.