Evaluation of distance and near stereoacuity and fusional vergence in intermittent exotropia.

ABSTRACT

Aim: To evaluate the role of distance and near stereoacuity and fusional vergence in patients with intermittent exotropia [X(T)] and their change after surgery. Materials and Methods: This prospective interventional institution-based clinical study included 31 cases of X(T) requiring surgery and 33 age, sex-matched controls. All subjects underwent complete orthoptic assessment including near stereopsis (Randot stereogram) and distance stereopsis by polaroid stereo-projector apparatus using special paired slides and fusional vergence assessment at distance and near prism bar at baseline and one week, one month, three months and six months after surgery in X(T). Results: The successful surgical alignment rate was 74.2%. Preoperatively, cases demonstrated significantly poor distance and near stereoacuity, compared to controls ( P P Conclusion: Early detection of abnormal stereoacuity (near and if possible distance) and near fusional vergence amplitudes may help to decide proper timing of surgery in X(T).