Vision screenings detect myopia fairly reliably in older children, found researchers in Australia, but results for hyperopia and astigmatism are less specific. These findings were published in the July issue of Archives of Ophthalmology.

Researchers examined 4,497 eyes of seventh grade students (mean age: 12.7 years). Each patient’s unaided acuity was tested monocularly at 2.44m with a retroilluminated logMAR chart.

Testing proved to be 97.8% sensitive and 97.1% specific for myopia, but 69.2% and 58.1% for hyperopia, and 77.4% and 75.4% for astigmatism, respectively. Researchers note that these results are based on specific acuity cutoffs—a VA cutoff of 6/9.5 (20/32) or less allows for the reliable prediction of refractive error; however, there is no reliable cutoff for clinically significant hyperopia or astigmatism.

“We’ve always known screenings are most effective at detecting myopia,”says Andrea Thau, O.D., trustee of the American Optometric Association and an InfantSEE founder. “Screenings are best designed to detect problems with distance acuity—and though that’s important, myopia represents the least risk for reading and learning problems.”

A myopic child is more likely to notice that the board is blurry and move to the front of the classroom, she explains, while those with hyperopia or astigmatism will have more difficulty reading and writing and may not be aware of their vision difficulty.

“According to the AOA’s Clinical Practice Guidelines, children should undergo comprehensive eye examinations at age 1, age 3 and age 5 and every year or two thereafter based on their optometrist’s recommendationsays,” Dr. Thau says. “Vision is not fully developed at birth, and tremendous changes in visual development [such as hyperopia and astigmatism] take place over the years that need to be monitored through regular comprehensive optometric examinations.”

Leone JF, Mitchell P, Morgan IG, et al. Use of visual acuity to screen for significant refractive errors in adolescents: is it reliable? Arch Ophthalmol. 2010 Jul;128(7):894-9.