ANAHEIM, Calif. -- A new study suggests that vision tests in preschoolers often fail to detect hyperopia(farsightedness), potentially robbing kids of an early opportunity to correct their eyesight.
"There is an inherent technical problem," said lead author Bruce Moore, OD, of New England College of Optometry in Boston. "We need to go back and understand what the problem is, and then we've got to find a fix."
While vision tests have been required in some U.S. school-age children since the 19th century, they've tended to be better at detecting myopia than hyperopia, said Moore, who spoke at a press conference at the American Academy of Optometry (AAOPT) annual meeting and in an interview with MedPage Today.
"Myopia is highly associated with increased school performance," he said. "We've had a system in place that identified [children] with vision problems associated with doing well," while other vision problems were missed.
Moore is an advocate for earlier vision testing and more focus on farsightedness, which can making reading difficult or impossible.
The new study aims to better understand the limitations of technology used in automated vision tests that detect refractive error. These devices are used because visual acuity tests are not ideal, Moore said. "Kids don't respond well to them, especially when they're performed by those who aren't doing the procedure properly."
Moore and colleagues reanalyzed data from a previous study of vision tests administered to 4,040 preschool-age children over 3 years. Using a referral criteria of 90% specificity for each screening test, the researchers examined how well the tests picked up cases of hyperopia ≥3 to ≤6 D (Group A) and with hyperopia ≥4 to ≤6 D (Group B) without amblyopia or strabismus.
Noncycloplegic retinoscopy correctly detected the cases 64% and 78% of the time, respectively; Retinomax picked up cases 64% and 75% of the time, respectively.
Other testing technologies detected the cases at lower levels: Power Refractor II (49% and 59%, respectively), Lea VA (48%, 53%), and Stereo Smile (30%, 38%).
Today, no one uses Retinomax for screening, Moore said. Newer vision testing devices are available, he said, but they rely on the same technology as the Power Refractor II.
Moore declined to recommend a vision testing device. Instead, he said it's "incumbent upon optometry and ophthalmology" to continue to work toward better screening techniques. "The technologies that exist today are without question a step in the right direction, but they're not at the level they need to be."