Abstract: Purpose: The present treatments for amblyopia are predominately
monocular aiming to improve the vision in the amblyopic eye through either
patching of the fellow fixing eye or visual training of the amblyopic eye. This
approach is problematic, not least of which because it rarely results in
establishment of binocular function. Recently it has shown that amblyopes
possess binocular cortical mechanisms for both threshold and suprathreshold
stimuli. Methods: We outline a novel procedure for measuring the extent
to which the fixing eye suppresses the fellow amblyopic eye, rendering what is
a structurally binocular system, functionally monocular. Results: Here we
show that prolonged periods of viewing (under the artificial conditions of
stimuli of different contrast in each eye) during which information from the
two eyes is combined leads to a strengthening of binocular vision in strabismic
amblyopes and eventual combination of binocular information under natural
viewing conditions (stimuli of the same contrast in each eye). Concomitant
improvement in monocular acuity of the amblyopic eye occurs with this reduction
in suppression and strengthening of binocular fusion. Furthermore, in a
majority of patients tested, stereoscopic function is established. Conclusions: This provides the basis for a new treatment of amblyopia, one
that is purely binocular and aimed at reducing suppression as a first step.
Keywords: Amblyopia, global motion, contrast, binocular summation, dichoptic interaction, treatment of amblyopia
