Original papers: Effects of diagnostic occlusion of the deviated and the dominant eye in intermittent exotropia

A previous study of intermittent exotropia has shown that diagnostic occlusion of the deviating eye often could reveal a vertical deviation that had not been recorded initially. The aim of the present study was to investigate if diagnostic occlusion of the dominant eye was still more effective in this respect. In 19 patients diagnostic occlusion was performed on the deviating eye as well as on the dominant eye. In 13 patients a vertical deviation could be elicited. The size of the vertical deviation was almost the same irrespective of which eye was occluded. The horizontal deviation both for distance and near was slightly larger after occlusion of the dominant than of the non-dominant eye. The fusion capacity was increased after occlusion more often after occluding the non-dominant than the dominant eye. Anomalies such as dissociated vertical deviations and A- and V-pattern were equally well diagnosed by occlusion of either eye. For a full diagnostic setup of patients with intermittent exotropia, occlusion of each eye separately is recommended in order to elicit maximal horizontal and vertical deviation.