Model developed for juvenile myopia prediction

Karla Zadnik

BOSTON — Spherical equivalent refractive error as measured by cycloplegic autorefraction, along with mild hyperopia at age 7 was found to be the best way to predict the onset of myopia in children between the ages of 8 and 14, according to a study presented here at Academy 2011 Boston.

Karla Zadnik, OD, PhD, FAAO, president of the American Academy of Optometry, reported at an academy-sponsored press conference that a method for predicting myopia would be effective "if there were a pharmaceutical treatment that could prevent eye growth or we could provide preventive optical treatment."

Candidate predictors included baseline refractive error, parental history of myopia, diopter hours, hours per week outdoors, axial length, lens thickness, corneal power, Gullstrand lens power, AC/A ratio, relative peripheral refraction, accommodative lag and astigmatism, Dr. Zadnik said.

"We evaluated five predictor models at each grade (1 to 6), and the best prediction we could do at the youngest age, we found we got reasonable prediction for grade 2," Dr. Zadnik told attendees. "At grade 1 the kids are all similar. We found that a model that only contained the cycloplegic spherical autorefraction equivalent was as good as models that used eight candidate predictors."

She added that the ability to predict those numbers increased with cycloplegic auotorefraction.

"If you look at our ability at average age 7 to predict at average age 9, 10, 11 and 12, what we find is our sensitivities for prediction are in the range of 70% to 80% and our specificity is in the range of 60% to 80%," Dr. Zadnik reported. "We can correctly identify 80% of future myopes and 70% of future nonmyopes. If you have a therapy available, you want to treat the ones you're supposed to treat."