Abstract
Dichoptic training is becoming a popular tool in amblyopia treatment. Here we investigated the effects of dichoptic training on juvenile amblyopia no longer responsive to patching treatment (PT group) or never patch treated (NPT group). Training consisted of three stages. (1) 10 PT and 10 NPT amblyopes (8-17 years, 15-anisometropic, 3-ametropic, 1-strabismus, 1-mixed) received dichoptic de-masking training for 40 hours. They used AEs to practice contrast discrimination of Gabors that were dichoptically masked by a band-filtered noise pattern simultaneously presented in NAEs. Dichoptic learning is indexed by the increase of maximal tolerable noise contrast (TNC) for AE contrast discrimination. Training improved maximal TNC by 350% in PT and 480% in NPT, which translated to stereoacuity improvements by 4.6-lines in PT and 3.0-lines in NPT, and AE visual acuity improvements by 1.3-lines in PT and 2.1-lines in NPT. (2) The amblyopes further received stereopsis training for another 40 hours. Training improved stereoacuity by 2.4-lines in PT and 0.5-lines in NPT, and AE acuity by 0 line in PT and 0.5 lines in NPT. Seven PT amblyopes regained normal stereoacuity (20~50 arcsec) after two stages of training. (3) Extra monocular AE grating acuity training (30 hours) failed to improve grating acuity in both groups. Neither did it produce further AE acuity and stereoacuity gains. After training the visual acuity and stereoacuity gains persisted for at least one year. Dichoptic training improved vision in both PT and NPT juvenile amblyopes. The PT group with milder amblyopia benefited substantially more in stereoacuity (6.0-lines), probably because improved AE acuity (1.3-lines) could translate to greater balance of binocular vision and thus better stereoacuity. The NPT group benefited more in visual acuity (2.6-lines), consistent with our previous report (Liu et al., 2011). Our study confirmed the effectiveness of dichoptic training approaches in the treatment of juvenile amblyopia.
Meeting abstract presented at VSS 2016