Alternative Flicker Glass: a New Anti-suppression Approach to the Treatment of Anisometropic Amblyopia.

Abstract

INTRODUCTION\nAmlyopia always presents with monocular and binocular dysfunction. In this study, we aim to investage the efficacy of alternative occlusion using liquid crystal glasses versus continuous occlusion therapy using traditional patches for treating amblyopia.\n\n\nMETHODS\nEligible subjects with anisometropic amblyopia were randomized into two groups: alternative flicker glass (AFG) or patching group. In the AFG group, subjects were instructed to wear the flicker glasses for 1 hour a day. The AFG is a lightweight spectacle frame with liquid crystal lenses that provide direct square-wave alternating occlusion, which were pre-programmed at temporal frequency of 7Hz. In the patching group, the patients were prescribed to wear traditional patches for 2 hours a day. The best corrected visual acuity (BCVA), contrast sensitivity function (CSF) and stereoacuity were measured at the baseline, 3 and 12 weeks.\n\n\nRESULTS\nIn this pilot study, a total of forty children were recruited, with twenty in the AFG group. Mean BCVA improved by 0.17±0.14logMAR (95% CI=0.10 to 0.23) in the AFG group, while 0.18±0.18logMAR (95% CI=0.09 to 0.26) in the patching group from baseline to 12 weeks. The improvement of BCVA in both groups were significant (both P＜0.01), while no significant difference between the groups (P=0.82). The CSF of both low and high spatial frequencies exhibited significant improvement at 12 weeks in the AFG group (P＜0.01, respectively), while just have a significant improvement at low spatial frequency in the patching group (P＜0.01). The stereoacuity significantly improved by 504.00±848.00 (95% CI= -900.88 to -107.12) arc seconds in the AFG group (P＜0.05), while 263.50± 639.55 (95% CI=-562.82 to 35.82) arc seconds in the patching group (P＞0.05).\n\n\nCONCLUSION\nAlternative flicker glass was effective in improving both monocular and binocular function, which was most likely achieved by reducing the suppression and promoting binocular fusion. This therapy exhibited promise as an alternative method for amblyopia treatment.