Visual acuity in northern China in an urban and rural population: the Beijing Eye Study

Abstract

Aim: To evaluate prevalence and demographic associations of visual impairment in an urban and rural population in northern China. Methods: In the Beijing Eye Study, a population based cohort study in northern China, visual acuity was assessed for 8876 eyes (4438 subjects) according to a response rate of 83.4%. The study was divided into a rural part (1972 subjects) and an urban part (n = 2466). Mean age was 56.20 (SD 10.59) years (median 56 years; range 40-101 years). Results: Mean uncorrected visual acuity measured 0.72 (0.32) (median, 0.80), and mean best corrected visual acuity measured 0.91 (0.21) (median, 1.0). In a multiple regression analysis, best corrected visual acuity was significantly correlated with age (p,0.001), degree of nuclear cataract (p,0.001), amount of cortical cataract (p = 0.014), amount of subcapsular cataract (p,0.001), educational background (p,0.001), and refractive error (p,0.001). Rural region versus urban region (p = 0.34) and sex (p = 0.053) were not statistically significantly associated with best corrected visual acuity. Conclusions: In northern China, determinants of a low degree of best corrected visual acuity are age, cataract, low educational background, and myopia. Despite marked differences in educational background and family income, sex, and rural area versus urban area are not markedly associated with best corrected visual acuity.V isual performance is of utmost importance for quality of life. It is described by several parameters such as visual field, colour vision, temporal resolution, and central visual acuity. It was the purpose of the present study to assess central visual acuity as one of the principal factors of visual performance in a population in northern China and to search for its ocular and demographic associations. SUBJECTS AND METHODSThe Beijing Eye Study is a population based prospective cohort study in northern China. It included, in total, 4439 subjects (8878 eyes; 2505 women) out of 5324 subjects asked to participate, corresponding to an overall response rate of 83.4%. The medical ethics committee of the Beijing Tongren Hospital had approved the study protocol and all participants had given informed consent, according to the Declaration of Helsinki. From the 8878 eyes, data on visual acuity were available for 8876 eyes (4438 subjects), which the present study comprised. The study was divided into a rural part (1972 (44.4%) subjects; 1142 women; 3944 eyes) and an urban part (2466 (55.6%) subjects; 1362 women; 4932 eyes) (table 1). Mean age was 56.20 (10.59 years (median, 56 years; range, 40-101 years).The survey was carried out in seven communities; four were selected from the Haidian urban district of the northern part of central Beijing, and three were selected from a rural district-that is, the county of Daxing District in the village area of Yufa situated south of Beijing. All people residing in the communities were officially registered, and home visits were performed according to the register. The eligible subjects were visited up to three times ...

Refractive error, ocular and general parameters and ophthalmic diseases. The Beijing Eye Study

“…It was carried out in four communities in the urban district of Haidian in the North of Central Beijing, and in three communities in the village area of Yufa of the Daxing District south of Beijing. The study has been described in detail recently [26,27]. The Medical Ethics Committee of the Beijing Tongren Hospital approved the study protocol, and all participants gave an informed consent according to the Declaration of Helsinki.…”

Associations between Gender, Ocular Parameters and Diseases: The Beijing Eye Study

“…It was carried out in 4 communities in the urban district of Haidian in the north of Central Beijing and in 3 communities in the village area of the Daxing District south of Beijing. The study has recently been described in detail [8][9][10] . The Medical Ethics Committee of the Beijing Tongren Hospital approved the study protocol, and all participants gave their informed consent according to the Declaration of Helsinki.…”

Capturing myopia and hypermetropia ‘phenotypes’ without formal refraction

“…[7][8][9] However, as well as the costs, time and practical constraints of using autorefractors in the field could be prohibitive in the context of very large non-ophthalmological studies. Thus important opportunities for research on refractive error would be missed.…”

“…4 Members have been followed since birth by clinical examination and/or face to face interview. At 7,11,16,41, and 44 years, data were collected at home by a trained nurse on vision and numerous other biological, social, and lifestyle factors. 4 We took the opportunity presented to us by our programme of work on vision and ophthalmic disorders in the 1958 British birth cohort (whose findings will be reported elsewhere) to undertake the present study.…”