Elsevier

Ophthalmology

Volume 115, Issue 11, November 2008, Pages 1965-1972.e1
Ophthalmology

Original article
Prevalence and Causes of Low Vision and Blindness in a Rural Chinese Adult Population: The Handan Eye Study

Presented as a poster at: Association for Research in Vision and Ophthalmology Annual Meeting, April 28–May 1, 2008 in Fort Lauderdale, Florida.
https://doi.org/10.1016/j.ophtha.2008.05.030Get rights and content

Purpose

To describe the prevalence and causes of low vision and blindness in a rural population in Northern China.

Design

Population-based, cross-sectional study.

Participants

A study of 6830 Han Chinese aged 30 years and older was conducted between October 2006 and October 2007 in rural Yongnian County in Handan, Northern China.

Methods

Clustered samples of adults aged 30 years or more residing in 13 residential villages were selected randomly and were invited to participate the Handan Eye Study. Participants underwent a comprehensive eye examination, including standardized visual acuity (VA) tests using logarithm of the minimum angle resolution charts. Prevalence was age- and gender-standardized to the 2000 China Census.

Main Outcome Measures

Low vision was defined as VA <20/60 but ≥20/400, and blindness was defined as VA <20/400 following the Modified World Health Organization (WHO) definitions. Primary causes of low vision and blindness were determined by study ophthalmologists according to WHO definitions.

Results

Six thousand eight hundred thirty (90.4%) of 7577 eligible individuals participated in the study, and 6799 (89.7%) had VA data available. Population-weighted prevalence of presenting bilateral blindness was 0.6% and bilateral low vision was 4.7% for persons 30 years of age and older. Based on best-corrected visual acuity (BCVA), the corresponding prevalence of blindness was 0.5% and that of low vision was 1.0%. Blindness and low vision were strongly age related (P<0.05). Cataract was the predominant cause of presenting bilateral blindness (36.6%), whereas undercorrected refractive error was the predominant cause of presenting low vision (78.4%). After refractive correction, cataract became the first leading cause of blindness (41.9%), and low vision (48.2%), myopic retinopathy (16.1%), glaucoma (9.7%), and corneal opacity (9.7%) were other common causes of blindness defined using BCVA.

Conclusions

A higher prevalence of blindness and low vision was seen in this rural Chinese sample than has been reported from urban Chinese populations. The estimated numbers with BCVA-defined low vision and blindness in 2020, based on best-corrected vision in rural Chinese adults aged 30 years or more, is expected to be 12.4 million and 2.9 million, respectively. Predominant causes of low vision and blindness in China are treatable.

Financial Disclosure(s)

The authors have no proprietary or commercial interest in any materials discussed in this article.

Section snippets

Study Design and Procedure

The study adhered to the Declaration of Helsinki, ethics approval was obtained from the Beijing Tongren Hospital Ethical Committee, and written informed consent was obtained from all participants. Residents of Yongnian County, Handan, Hebei Province, aged 30 years and older were selected randomly using a stratified, clustered, sampling technique with probabilities proportionate to the size of the population in each cluster. In Yongnian County, 90% of the population are farmers, and 98% are Han.

Results

Of the 7557 eligible subjects, 6830 took part in the study (90.4% response rate). One hundred forty-two (1.9%) declined to participate, 137 (1.8%) ide of Yongnian County. Of the 6830 participants, 5909 (86.5%) were examined in the hospital clinic, 807 (11.8%) in a temporary study site at the village, and 114 (1.7%) at home. Compared with nonparticipants, those who participated were more likely to be female, to be older, to have obtained more years of education, and to be married (Table 1).

Discussion

We found that the population-weighted prevalence of bilateral visual impairment based on presenting VA was 2.7% in rural Chinese adults 30 years of age and older. If defined using BCVA, the population-weighted prevalence of bilateral blindness was 0.5% and that of bilateral low vision was 1.0%. In persons 40 years of age and older, the age-standardized prevalence of bilateral BCVA-defined blindness was 0.7% and that of low vision was 1.5%. These prevalence rates of blindness and low vision are

References (27)

  • Major Figures of the 2000 population census

  • China PopulationAnnual report of Chinese resident's income 2006 [in Chinese]

  • M. He et al.

    Prevalence and clinical characteristics of glaucoma in adult Chinese: a population-based study in Liwan District, Guangzhou

    Invest Ophthalmol Vis Sci

    (2006)
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    Manuscript no. 2008-266.

    A list of study group members and study collaborators is available at http://aaojournal.org.

    Financial Disclosure(s): The authors have no conflicts of interest with regard to this article.

    Supported by the National Basic Research Program of China (973 Program; no. 2007CB512201) from the Ministry of Science and Technology, Beijing, People's Republic of China; the Program of Health Policy for Blindness Prevention, People's Republic of China; the Key Technologies R&D Program (no. 2006-10903), Bureau of Science and Technology of Handan City, People's Republic of China; Beijing Tongren Hospital, Beijing, People's Republic of China; and the Bureau of Health, Handan City, Hebei Province, People's Republic of China.

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