Visual acuity analysis most effective in detecting adolescent myopia

Visual acuity analysis most effective in detecting adolescent myopia

Arch Ophthalmol. 2010;128(7):894-899.

Monocular visual acuity measurement proved reliable in detecting myopic refractive error in a group of adolescents, a large population study showed.

"In this adolescent group, a VA cutoff of 6/9.5 or less detects myopic refractive error reliably," the study authors said. "However, there is no reliable VA cutoff for clinically significant hyperopia or astigmatism. Improved VA screening methods are required to improve detection of these conditions. Even so ... the prevalence of uncorrected VA may provide a reasonably accurate estimate of the prevalence of myopia."

The Sydney Myopia Study included students attending seventh grade (mean age: 12.7 years) at 21 secondary schools in Sydney, Australia. Investigators assessed monocular logMAR visual acuity and used cycloplegic autorefraction to define clinically significant refractive error spherical equivalent of -1 D or less for myopia, +2 D or more for hyperopia and -1 D or less cylinder for astigmatism.

Data analysis for both eyes involved 4,497 observations.

Study data showed that myopia had the highest sensitivity (97.8%) and specificity (97.1%) for detecting refractive error at a 45-letter cutoff (6/9.5). The best visual acuity cutoff for hyperopia was 57 letters, and the best cutoff for astigmatism was 55 letters.

Hyperopia showed visual acuity sensitivity of 69.2% and specificity of 58.1%. Astigmatism showed sensitivity of 77.4% and specificity of 75.4%, the authors reporte