18:00 PM

Ethnicity Plays Role In Vision Problems, Research Suggests

COLUMBUS, Ohio -- Ethnicity appears to be associated with vision problems -- such as near- and farsightedness -- in children, new research suggests.

Karla Zadnik

Researchers found that Asian-American children were more likely to be myopic, or nearsighted, than their Hispanic, African-American and white peers, while white children were more likely to have hyperopia, or farsightedness, than were children from the other ethnic groups. Astigmatism -- an irregular curvature of the cornea that causes blurry vision -- was most prevalent among Hispanic children.

"We don't really know why these differences exist," said Karla Zadnik, the lead author of the multi-center study and an associate professor of optometry at Ohio State University. "It's probably like most of our modern conditions and diseases a mix a nature and nurture and factors that interact together.

In this study, 18.5 percent of the Asian children were nearsighted thats more than four times the number of nearsighted white children; three times the number of farsighted African American children; and one-and-a-half times the number of nearsighted Hispanic children.

"But uncorrected vision problems are a major public health problem, and a large number of children are visually handicapped in their everyday classroom, recreational and other activities."

Nearly one out of five Asian-American children in the study was nearsighted, and one out of five white children was farsighted. More than a third of the Hispanic children had astigmatism.

The results appear in the current issue of the Archives of Opthalmology.

The researchers evaluated the vision of 2,523 children from four ethnic groups: 534 were African American; 491 were Asian; 463 were Hispanic; and 1,035 were white. These findings were part of the Collaborative Longitudinal Evaluation of Ethnicity in Refractive Error (CLEERE) Study, an eight-year study that looks at the prevalence of vision problems -- myopia, hyperopia and astigmatism -- across ethnic groups. The CLEERE study is in its fifth year.

Parents filled out questionnaires covering their childrens medical history and also indicated their childs ethnicity. The children were in grades one through eight at the time of the study and lived in communities in Alabama, California and Texas. Each child was evaluated in his or her respective school.

In this study, 18.5 percent of the Asian children were nearsighted -- thats more than four times the number of nearsighted white children (4.4 percent); three times the number of farsighted African American children (6.6 percent); and one-and-a-half times the number of nearsighted Hispanic children (13.2 percent.)

On the flip side, nearly one in five white children (19.3 percent) were farsighted -- three times the number of both farsighted Asian children (6.3 percent) and farsighted African-American children (6.4 percent), and one-and-a-half times the number of farsighted Hispanic children (12.7 percent).

Astigmatism ran fairly high in each group, with Hispanic children having the highest prevalence (37 percent), followed by Asian children (34 percent), white children (26 percent) and, finally, African-American children (20 percent.)

The researchers are also studying the rate at which childrens eyes change during their elementary and middle school years.

"About 2 percent of children are nearsighted when they enter school," Zadnik said. "Children tend to develop myopia between 8 and 12 years old. In fact, most first graders are slightly farsighted when they begin school.

"As the body grows, that farsightedness tends to decrease," she continued. "But for reasons that are still unclear, a childs eyes sometimes keep growing until he or she reaches her teen years. Its this growth that, in some cases, contributes to nearsightedness."

Zadnik conducted the study with fellow Ohio State optometry colleagues Lisa Jones and Donald Mutti; Robert Kleinstein, of the University of Alabama, Birmingham; Sandral Hullett, of West Alabama Health Services; Soonsi Kwon, Robert Lee and Julie Yu, all with the Southern California College of Optometry, Fullerton; Nina Friedman, with the University of California, Berkeley; and Ruth Manny, with the University of Houston.

The researchers received funding from the National Institutes of Healths National Eye Institute; the NIH National Center for Minority Health and Health Disparities (formerly the Office of Minority Research); the Ohio Lions Eye Research Foundation; and the E. F. Wildermuth Foundation in Columbus.


Contact: Karla Zadnik, (614) 292-6603; Zadnik.4@osu.edu From August 9 through August 22, Zadnik can be reached at (888) 431-6117.

Written by Holly Wagner, (614) 292-8310; Wagner.235@osu.edu