Proposed acuity testing protocol shows promise

Simulations indicate the Amblyopia Treatment Study protocol is an accurate method for assessing visual acuity in children between 3 and 6 years old.

Joost Felius, PhD, and colleagues at the Retina Foundation of the Southwest in Dallas studied the accuracy of the Amblyopia Treatment Study (ATS) by using Monte Carlo computer simulations to recreate a psychometric model accounting for true acuity, with noise in the visual system and the rate of inadvertent misses. The rate of inadvertent misses ranged from 0% to 10%, according to the authors. The accuracy of the ATS protocol was evaluated in terms of precision, bias and stimulus range limitations. Acuity, visual system noise and level of attentiveness in 126 children between the ages of 3 and 6 were also studied.

For conditions with little noise in the visual system, precision was within 0.1 logMAR, except for acuities worse than 1.2 logMAR. Bias was negligible except in noisy conditions, and the effects of inadvertent misses were small, according to the authors.

The study is published in the Journal of the American Association of Pediatric Ophthalmology and Strabismus.