| Objective: Visual impairment not only makes the patient himself a great suffering, but also contributes to the burden of the family and the whole society. Nowadays, it has already been a serious public health, social and economic problem worldwide. So, it is very important to facilitate reduction of the blindness. A global initiative for elimination of avoidable blindness under the title"VISION 2020: The Right to Sight"was launched on February, 17th, 1999 by the World Health Organization in collaboration with a number of international nongovernmental organizations. Responsing to this action, we carry on a population based study among persons 40 years or older living in the countryside of Pingxiang County, HeBei Province which has beening the badly surpporting poverty-striken area. In order to have a knowledge about the prevalence of blindness, low vision, tracoma, pterygiun and other external eye diseases, so as to contribute to the blindness prevention and the resource of the epidemiology data in our country.Meanwhile there are considerable persons in the countryside in our country who are too poor to pay for the health cost, but to give up the opportunity to cure their eye disease. Forthermore, there are less concept and technique to avoid blindness, and there are less screening for the eye diseases in patients. So, another purpose of the study is to detect the eye diseases, help the crowd to discover and treat the diseases earlier. In hope that it will make a little contribution to lessen the burden of the society, and to the construction of the new socialism countryside.Methods:1 Calculated the sample size according to the formula below: n=(uα/δ)~2p(1-p)Sample size requirements were based on estimating with 95%confidence interval(95%CI), within an error bound of plus or minus 20%, the bilateral blindness prevalence of the persons 40 years or older used for sample size calculation was 1.75%, which was based on preliminary results from the survey conducted in Shunyi County. Assuming an examination response rate of 85%, a sample size of 6 344 was required.2 Multistage stratified cluster random sampling, with proportional to size procedures, was adopted as the strategy for the selection of the population. Examinations were carried out in a temporary examinating station after gathering the persons together.3 Recorded the name, sex, age, general disease, eye case history, family case history and eye operation history of every subject. Tested the visual acuity with international standard visual acuity chart. Pinhole vision was measured in all eyes failed to present with acuity of 0.3 or better. Examinated the external eye conditions under sunlight or with an electric torch. The eyes failed to present with pinhole visual acuity of 0.3 needed further examination by a slit lamp and direct ophthalmoscope.4 Made the diagnoses of different diseases according to the criteria, and established database using Excel 2003. Calculated the prevalence separately, and analysed the data using SAS software.Result:1 Study subjects: A total of 7 153 subjects were registered, consisted of 3 341 males and 3 812 females. 6 455 subjects were examined, the response rate was 90.24%. Among the 6 455 participants, 2 985 were male, 3 470 were female, and the response rate was 89.34%, 91.03% respectively.2 Prevalence of trachoma: The prevalence of trachoma was 21.13% (95%CI: 20.13%-22.13%). The prevalence of the female (25.48%) was significantly higher than that of the male (16.08%). There was no obviours association between prevalence and age. Of all the stages, stage II was at most, occupided 43.69% of all the sufferers. As to the severity, the light (I~+ and II~+) type was the commonest, occupied 47.58%.3 Prevalence of pterygium: The prevalence of pterygium was 6.35% (95%CI: 5.76%-6.94%). The prevalence of the male (7.37%) was significantly higher than that of the female (5.48%). The prevalence of pterygium increased with age before 80 years old, but decreased after 80 years old. 96.10% of the pterygium occurred at the nasal side. And of all the grades,"2mm～"was the most, occupided 35.66%,"5mm～"was the least, occupided 1.13%.4 Prevalence of other diseases: Conjunctival concretion had a high prevalence which was 11.23%. The prevalence of corneal opacity caused by various diseases was 2.42%. The prevalence of other disease, such as trichiasis, entropion, strabismus, chronic dacryocystitis, ectropion was 1.84%, 1.13%, 0.73%, 0.60%, 0.25% respectively.5 Prevalence of blindness and low vision: The prevalence of bilateral blindness, bilateral low vision, unilateral blindness, unilateral low vision was 1.10% (95%CI: 0.85%-1.35%), 2.80% (95%CI: 2.40%-3.20%), 2.40% (95%CI: 2.03%-2.77%), 3.16% (95%CI: 2.73%-3.59%) respectively. Of all the different types of visual impairment, the prevalence of female was significantly higher than that of male. And all the prevalence was increased with age. According to the primary causes of visual impairment, cataract was the leading cause. Among the definite causes, corneal disease was the second, and then was excessive myopia and amblyopia. The complication of trachoma occupied 3.01% of all the causes. And pterygium occupied 0.70%.Conclusion: Trachoma is no more the main cause of blindness, but still has a high prevalence. So, in the future, as a prevention, we should enhance health knowledge education to help the crowd form a good hygienic habit, so as to cut off the transmission. Pterygium is a potential cause of blindness. So, still, we should treat it as a important aspect of the prevention sphere, and strengthen the protective device in the outdoor work. Cataract is the leading cause of blindness, and as the population ages, the blindness due to cataract will increase continuely. So, prevention of blindness caused by cataract will still be a main issue. As the prevalence of blindness and low vision increasing with age, populations 60 years or older should be the more important protection crowd. Great efforts are needed in order to significantly reduce the prevalence of visual impairment.
|
PDF Full Text Request