Correction of Hypertropia Coexisting with Intermittent Exotropia

PURPOSE: To investigate the clinical features associated with hypertropia and report the surgical outcomes of hypertropia coexisting with exotropia. METHODS: We reviewed the medical records of 148 patients with intermittent exotropia coexisting with hypertropia over 4 PD who received exotropia surgery. The cases accompanied by apparent paralytic strabismus such as superior oblique palsy were excluded. Patients were divided into group I(clinically diagnosed hypertropia) and group II (non-specific hypertropia) and the clinical features of coexisting hypertropia and surgical outcomes were analyzed. RESULTS: Among the 148 patients, group Iconsisted of 38 patients (26%) and group II of 110 patients (74%). The average amount of preoperative hypertropia angle in primary gaze was 9.58 +/- 3.89 PD and 6.62 +/- 2.69 PD in group I and II, respectively. Group I included 12 patients with dissociated vertical deviation (DVD), 10 patients with unilateral inferior oblique overaction, 13 patients with asymmetric bilateral inferior oblique overaction and 3 patients with superior oblique overaction. Group II included 19 patients with comitant hypertropia (17%), head tilt positive pattern (simulated superior oblique palsy) was found in 84 patients (76.3%) and variable incomitance was observed. In group I, 29 patients received simultaneous horizontal muscle with hypertropia surgery. Postoperative hypertropia angle in group I was 1.41 +/- 2.93 PD and 4 cases were considered surgical failure. In group II, hypertropia was resolved with horizontal muscle surgery only and the amount of postoperative hypertropia was 0.45 +/- 1.60 PD. CONCLUSIONS: In this study, vertical deviations in intermittent exotropia with concomitant hypertropia related to obvious oblique muscle dysfunction or DVD were corrected effectively by oblique or vertical rectus muscle surgery. Nonspecific hypertropia can be resolved after horizontal muscle surgery alone, however, for precise differential diagnosis, careful examination for variable clinical features is necessary before determining surgery.

Intermittent Exotropia Associated with Simulated Superior Oblique Palsy

PURPOSE: To obtain guideline of diagnosis and treatment when hyperdeviation associated with intermittent exotropia shows symptoms similar to superior oblique palsy (SOP). METHODS: We reviewed the charts retrospectively in 27 patients showing simulated SOP in intermittent exotropia, in which hyperdeviation in primary gaze and 10PD or more by Bielschowsky head tilt test were present. Overaction of Inferior oblique, (IOOA) dysfunction of superior oblique, and forveal extorsion more than +2 were excluded including reoperation and head tilt history. All patients were undergone horizontal muscle surgery only. The postoperative changes of deviation were analyzed at postoperative one day, one month, six month, and one year. RESULTS: Average amount of distant horizontal deviation in primary gaze was 32.3+/-9.58PD. Hyperdeviation was 3.8+/-2.52PD. Degree of IOOA averaged +1.18 in hypertropic eye, and +1.06 in hypotropic eye. Only 10 patients (37%) had foveal extorsion less than +2 in degree. Average vertical deviation of hypertropic eye side was 12.7+/-2.93PD on head tilt test. After horizontal surgery only, the amount of hyperdeviation decreased to 1.3PD at 1st day. On head tilt test, hyperdeviation was almost eliminated showing 0.6PD on the hypertropic side and 0.1PD on the contralateral eye at one month. All patients were aligned up to the follow-up of one year. CONCLUSIONS: To differentiate simulated SOP from intermittent exotropia with hyperdeviation, none of head tilt history, mild foveal extorsion, mild oblique dysfunction less than +3, double Maddox rod test, and forced duction test are important guidelines. Horizontal muscle surgery is only needed to remove exodeviation and hyperdeviation.