Binocular vertical perceptual adaptation in essential infantile esotropia.

This study assessed whether dissociated vertical deviation, corresponding to an occasional elevation of the deviated eye, is accompanied by a binocular vertical perceptual adaptation. Dissociated vertical deviation was elicited by means of neutral filters in 16 patients, 8 who had undergone operations for the disorder of essential infantile esotropia and 8 who had not. Neutral filters elicited dissociation vertical deviation, which was accompanied by binocular vertical perceptual adaptation. This effect was significantly greater for patients who had operations and was enhanced by the filter density. Surgical elimination of inhibitory mechanisms for dissociated vertical deviation in patients with essential infantile esotropia appears to facilitate a loose sensory adaptation, which permits a binocular vertical perceptual adaptation.