Here's how you can predict nearsightedness in kids

A new study has identified a single test that can predict which kids will become nearsighted by the eighth grade.

The study conducted at Ohio State University surveyed 4,500 U.S. children over 20 years and assessed 13 potential risk factors for nearsightedness to determine the strongest single predictor or set of predictors that could identify those children most likely to develop myopia.

Karla Zadnik, professor and dean of the College of Optometry at The Ohio State University and lead author of the study, said that near work has been thought to be a cause of myopia, or at least a risk factor, for more than 100 years and some of the studies that led to that conclusion are hard to refute.

The study involved 4,512 children between first and eighth grades. When they were between the ages of 6 and 11 years, children with normal vision were evaluated at this range of baseline ages and at least two additional annual visits. Over the course of the study, 414 kids became nearsighted between second and eighth grades.

Statistical analysis, however, showed that the refractive error at baseline was the best predictor in children at a young age that they would develop myopia by their teen years.

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 and in people with myopia, the typically spherical eyeball becomes elongated, resembling the shape of a grape or an olive.

According to the study, kids who will grow up with normal vision are actually slightly farsighted when they are in first grade and, therefore, the potential for future myopia can be detected at this young age via a refractive error measure that reveals little to no farsightedness.

Zadnik added that as people become aware of a test for their first-grader that would help predict whether their child will need glasses for nearsightedness, myopic parents who want to have this information about their kids could lead to rapid adoption of this test.

The study is published in the issue of the journal JAMA Ophthalmology.