Purpose: To investigate the clinical features and obtain guideline of treatment in intermittent exotropia associated with hypertropia including simulated superior oblique palsy. Methods: We retrospectively reviewed the charts of 93 patients of intermittent exotropia aligned with horizontal muscle surgery only, who showed hypertropia more than 2PD in primary gaze before surgery and disappeared after surgery. They showed forveal extorsion and dysfunction of oblique muscles of 2+ or less and positive Bielschowsky head tilt test. The postoperative changes of deviation angle were analysed at postoperative 1 day, 6 months, and 1 year. Results: Average amount of distant horizontal deviation in primary gaze was 32.3±9.58 (25-53)PD, hypertropia was 3.50±2.52 (2-14)PD. Average vertical deviation of ipsilateral (hypertropic eye) side was 8.8±4.63PD and contralateral (hypotrophic eye) side was 4.0±4.77PD in Bielschowsky head tilt test. Hypertropic eye was accorded with exotropic eye in 53.4%. After horizontal surgery, the amount of hypertropia was 1.2PD at postoperative 1 day. On Bielschowsky head tilt test, hypertropia was almost eliminated showing 0.6PD on the ipsilateral side and 0.2PD on the contralateral eye at 1 month. This state was maintained up to postoperative 1 year. Conclusion: Small amount of hypertropia up to 14PD in intermittent exotropia could be disappeared with horizontal muscle surgery only. However, careful examinations for head tilt history, fovea extorsion, oblique dysfunction, and Maddox rod test should be preceded to rule out true superior oblique palsy.
ASJC Scopus subject areas
- Sensory Systems