The therapeutic impact of perceptual learning on juvenile amblyopia with or without previous patching treatment

To investigate the therapeutic impact of perceptual learning on juvenile amblyopia that is no longer responsive to patching treatment (PT group) or was never patch treated (NPT group).

Ten PT and 13 NPT subjects aged 8 to 17 years were trained with a grating acuity task for 40 to 60 sessions. Half in each group were further trained with single or crowded tumbling E acuity tasks for 8 to 10 sessions.

Training improved grating acuity by -2.1% in the PT eyes and 36.1% in the NPT eyes, along with a boost of single and crowded E acuities by 0.9 or 0.7 lines in the PT eyes and 1.5 and 1.2 lines in the NPT eyes, in contrast to a nearly 5-line improvement in the same PT eyes after previous patching treatment. Stereoacuity was improved in some PT and NPT eyes. The single and crowded E acuity improvements were not significantly dependent on the pretraining acuity. The single and crowded E acuity and stereoacuity improvements were uncorrelated with grating acuity improvement, suggesting some random training impacts on different tasks and individuals. Further direct single and crowded E acuity training generated an additional 0.2- and 0.2-line boost for PT eyes and a 0.4- and 0.5-line boost for NPT eyes, resulting in overall single and crowded E acuity gains of 1.4 and 1.0 lines for PT eyes and 2.2 and 1.8 lines for NPT eyes.

Perceptual learning has a small but significant therapeutic impact on both PT and NPT juvenile eyes, which is most likely to have clinical values for eyes with mild amblyopia. Early diagnosis and treatment are most important and effective.