Influence of extraocular muscle imbalance on binocular performance.

In assessing binocular performance, it is possible that extraocular coordination is more significantly involved than presently recognized. Dynamic phorometry or phorometric testing in the nine cardinal directions of gaze is advised for evaluating the extraocular muscular system. These case reports used interrelation of phorias to evaluate binocular problems. The interpretation of these data helps determine the amount of horizontal prism necessary to reduce compensating vergences. Although a control group was not used, the elimination of associated vertical fixation disparity in these cases seemed to ameliorate binocular stress.