Abstract
Purpose:
To evaluate the efficacy of Eyetronix Flicker Glass therapy in treating anisometropic amblyopia by breaking interocular suppression and promoting binocular fusion.
Methods:
Thirty subjects with anisometropic amblyopia, ages 7 to 13, were enrolled in this study. A novel stimulus of Eyetronix Flicker Glass, a lightweight spectacle frame with liquid crystal lenses that provide direct square-wave alternating occlusion, was used at a pre-programmed temporal frequency of 7 Hz. Visual acuity, contrast sensitivity (CSV-1000E charts) of 3, 6, 12 and 18 cycles per degree spatial frequencies and binocular function were measured at baseline and follow-up visits at weeks 1, 3, 6, 9 and 12 to assess improvement of amblyopia. In addition, pattern-reversal visual evoked potential (RETIport32) was used to record visual cortex activity before and after treatment.
Results:
After Eyetronix Flicker Glass therapy, visual acuity significantly improved from 0.45±0.23logMAR to 0.27±0.22logMAR. Thirteen children (48%) had two lines or more visual acuity improvement. Contrast sensitivity of 3, 6, 12 and 18 cycles per degree spatial frequencies showed significant improvement at the visits of 3, 6, 9 and 12 weeks. Mean stereoacuity (Titmus test) improved from 241 seconds to 80 seconds. Stereoacuity in 11/30 children recovered to 60 seconds. In addition, there was a decreased P100 latency and increased N75-P100 amplitude of visual evoked potential after treatment.
Conclusions:
EyeTronix Flicker Glass showed promise as an alternative method for amblyopia treatment. It was effective in improving both monocular and binocular function, likely by reducing suppression and stimulating recovery of the visual cortex.