Karla Zadnik, Ohio State – Improving Optometry

Karl Zadnik
Photo by Jo McCulty

New research is helping to predict nearsightedness.

Karla Zadnik, Glenn A. Fry Professor of Optometry and Physiological Optics and Dean at The Ohio State University College of Optometry, discusses the new test she is developing.

Karla Zadnik is the Glenn A. Fry Professor of Optometry and Physiological Optics and Dean at The Ohio State University College of Optometry. She received her OD and PhD degrees from the University of California, Berkeley School of Optometry. She has chaired the Biomedical Sciences Institutional Review Board (IRB) at Ohio State for the last ten years. Professor Zadnik is a Fellow of the American Academy of Optometry and served as the Academy’s President in 2011-12. She received the American Optometric Foundation’s Glenn A. Fry Award in 1995. She served on the National Advisory Eye Council of the National Eye Institute (NEI)/National Institutes of Health from 2000 to 2004. Dr. Zadnik was the Study Chairman for the NEI-funded Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study and chaired the first-ever NEI-funded multicenter study based in optometry, the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study from 1994 through 2007. She received a Distinguished Scholar Award from Ohio State in 2010.

Improving Optometry

Many of us heard as kids that we were ruining our eyes if we sat too close to the tv or read with a flashlight under the bed covers. But after studying risk factors for nearsightedness in young children for 20 years, my colleagues and i found that near work – frequent reading, video games, and, yes, even sitting close to the tv – is not a risk factor for becoming nearsighted.

Our study identified a single test that can predict which children will become nearsighted by the 8th grade. It’s a measure of their current refractive error, or eyeglasses prescription, when they are between 6 and 11 years old. The refractive error results from mismatches in the size and optical power of the eye that lead to blurry vision or eyestrain.

If you’ve ever had an eye exam, you’re familiar with how optometrists measure refractive error. We change lenses in a machine as patients view a distant eye chart and we ask, “which is better, one or two?” In this study, we used an auto-refractor to measure each child’s refractive error annually.

In people with normal vision, the eyeball grows along with the rest of the body and is programmed to stop growing at a point that sustains clear vision. In people with myopia, or nearsightedness, the typically spherical eyeball becomes elongated, resembling the shape of a grape or an olive, and distant objects focus in front of the retina at the back of the eye, producing an out-of-focus image.

Kids who will grow up with normal vision are actually slightly farsighted when they are in the 1st grade. Because of that, the potential for future nearsightedness can be detected at this young age if the child’s refractive error measurement reveals little to no farsightedness.

About one in three adults in the united states is nearsighted, but the condition begins in childhood. Our results can help the optometrist establish an individualized schedule of eye care for each young patient across the school years.

Read More: OSU.edu: ​One test can predict which kids will become nearsighted