Restoration of Binocular Vision in Amblyopia

Abstract

Purpose: To develop a treatment for amblyopia based on re-establishing binocular vision.

Methods: A novel procedure is outlined for measuring and reducing the extent to which the fixing eye suppresses the fellow amblyopic eye in adults with amblyopia. We hypothesize that suppression renders a structurally binocular system, functionally monocular.

Results: We demonstrate that strabismic amblyopes can combine information normally between their eyes under viewing conditions where suppression is reduced by presenting stimuli of different contrast to each eye. Furthermore we show that prolonged periods of binocular combination 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. Additionally, stereoscopic function was established in the majority of patients tested. We have implemented this approach on a headmounted device as well as on a handheld iPod.

Conclusion: 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

ACKNOWLEDGMENT

This study is supported by a CIHR grants (#MOP 53346 & Mt108-18) to RFH and a University of Auckland FRDF grant to BT. We wish to acknowledge the collaboration of Goro Maehara, Long To, Jeremy Cooperstock, Jeff Blum, William Bobier, Peng Zhang, and Joanne Black.

Declaration of interest: The author has applied for patents related to the binocular treatment of amblyopia using a gaming approach.