Chinese American adults in the United States have a substantially higher prevalence of myopia, high myopia, and astigmatism than do U.S. adults in other racial/ethnic groups, according to a large population-based study in California.1
Highest rates in the world. “These rates, particularly in the 50- to 75-year-old group, are the highest of any study of Chinese [people] done anywhere in the world. And that’s something we didn’t expect,” said Rohit Varma, MD, principal investigator in the Chinese American Eye Study. Dr. Varma is professor and chair of ophthalmology at the University of Southern California, in Los Angeles, as well as dean of the Keck School of Medicine and director of the USC Roski Eye Institute.
Funded by the National Eye Institute, the Chinese American Eye Study recruited and conducted comprehensive refractive exams on 4,144 adults (aged 50 years and older) of Chinese ancestry in the Southern California city of Monterey Park.
Analysis of the data revealed that, overall:
- Prevalence of myopia (greater than –0.5 D) was 35.1%; in comparison, the age-adjusted rate was 26.2% among the white subjects in the Beaver Dam Eye Study.2
- Prevalence of high myopia (greater than –5.0 D) was 7.4%. This was almost twice as high as the rate in the Beaver Dam study.
- Prevalence of astigmatism was 45.6%.
- Prevalence of hyperopia was 40.2%.
- Myopia prevalence decreased with age, and hyperopia increased.
“These data provide the first population-based estimates of refractive error in Chinese Americans,” Dr. Varma said. Because of the known high prevalence of myopia in Asian nations, the authors had assumed Chinese Americans had more myopia than other groups in the U.S. “but we didn’t really know,” he said.
1 Varma R et al. Am J Ophthalmol. Published online Oct. 18, 2016.
2 Wang Q et al. Invest Ophthalmol Vis Sci. 1994;35(13):4344-4347.
Relevant financial disclosures—Dr. Varma: None.
For full disclosures and disclosure key, see below.
More from this month’s News in Review