The use of rotating gratings for the treatment of amblyopia: a clinical trial

The use of rotating gratings for the treatment of amblyopia was subjected to a controlled clinical trial. A treatment group (N = 19) observed rotating gratings for 15 min per week for 10 weeks and a control group (N = 19) observed a blank rotating disk for the same period. Both groups of amblyopes performed visually guided tasks to maintain their interest during treatment. Data were acquired in a double-masked manner. A second control group (N = 4) underwent weekly acuity evaluation without any form of treatment. Visual acuity was evaluated before and after each session and analyzed with a linear regression fit to a probit transform by a minicomputer. By using a criterion change in acuity of 10% Snell Sterling, we found no significant change of acuity in any group or between groups. These results demonstrate that rotating gratings are an insignificant variable in the treatment of amblyopia.