Elsevier

Ophthalmology

Volume 117, Issue 3, March 2010, Pages 409-416.e1
Ophthalmology

Original article
Prevalence of Vision Impairment in Older Adults in Rural China: The China Nine-Province Survey

https://doi.org/10.1016/j.ophtha.2009.11.023Get rights and content

Purpose

Describe the prevalence of visual impairment/blindness among older adults in rural populations in China.

Design

Population-based, cross-sectional study.

Participants

We evaluated 45 747 adults ≥50 years of age.

Methods

Geographically defined cluster sampling was used in randomly selecting a cross-section of residents from a representative rural county within each of 9 provinces in mainland China. Participants were enumerated through village registers followed by door-to-door household visits. Eligible persons were invited to local examination sites for visual acuity (VA) testing and eye examination.

Main Outcome Measures

Presenting and best-corrected distance VA.

Results

Of 50 395 enumerated eligible persons, 45 747 (90.8%) were examined and tested for VA. The prevalence of presenting visual impairment <20/63 to ≥20/400 in the better eye was 10.8% and blindness (<20/400) was 2.29%. Across the 9 provinces, presenting visual impairment ranged from 6.89% to 15.8%, and blindness from 1.27% to 5.40%. With best-corrected VA, the prevalence of visual impairment was 5.30%, and 1.93% for blindness. The ranges across the 9 provinces were 3.13% to 9.51% for visual impairment and 0.74% to 4.95% for blindness. Visual impairment and blindness were associated with older age, female gender, lack of education, and geographic area (province) with both presenting and best-corrected VA.

Conclusions

Visual impairment and blindness are important public health problems in rural China, with significant regional variations in prevalence. Blindness prevention programs targeting the rural elderly should be expanded, particularly in areas with limited access and affordability of eye care services. Special emphasis should be given to reaching women and those without education. Greater attention should also be given to correction of refractive error.

Financial Disclosure(s)

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

Section snippets

Materials and Methods

The surveys were carried out in a randomly selected sample of individuals within each county. Major urban areas within the county were excluded. The sampling frame was constructed using geographically defined clusters based on village register data. Cluster boundaries were defined such that each cluster would have a population of approximately 1000 individuals (all ages).

Sample size was based on estimating an anticipated 4% prevalence for visual impairment <20/200 within an error bound

Results

A total of 50 395 persons aged ≥50 years were enumerated, with distribution across age, gender, education and province (Table 1). The mean age of the enumerated population was 62.1 years, ranging from 58.6 years in Xinjiang to 64.8 years in Guangdong. Overall, 45.8% were males, ranging from 42.7% in Jiangxi to 50.2% in Guangdong. Nearly 30% of those enumerated were without education, ranging from 3.69% in Hebei to 62.8% in Yunnan; education at the secondary level or higher was 18.3%, ranging

Discussion

The strengths of this survey were the large, randomly selected sample of participants and use of the same study protocol at each site. Examination response rates generally exceeded 90%, which was achieved by repeat household visits to seek participation and by offering examinations at home when necessary. The notably low examination response rate in Yangxi county (Guangdong) was due in part to the composition of the enumeration team, which was from the urban center of the county in Yangjiang

References (14)

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Manuscript no. 2009-1182.

A list of study team members for each of the 9 sites appears in Appendix 1 (available online at http://aaojournal.org).

The co-authors from the provinces contributed equally to this work.

Financial Disclosure(s): The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Supported by the Chinese Ministry of Health, Beijing, China; the World Health Organization, Geneva, Switzerland (under National Institutes of Health [Bethesda, Maryland] contract no. N01-EY-2103); and the Lions Clubs International Foundation, Oak Brook, Illinois. The sponsor or funding organizations participated in the design of the study.

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