Results of combined resection-recession on a single rectus muscle for incomitant deviations-an alternative to the posterior fixation suture.

PURPOSE: To compare outcomes of combined resection and recession on previously unoperated single horizontal or vertical rectus muscles in consecutive adult patients with acquired incomitant deviations minimal in primary gaze and maximal in an eccentric gaze position.

METHODS

The surgical goal was to decrease the incomitance by 50%, expand the field of binocular single vision, and relieve diplopia. Recessions for the maximal deviations were combined with smaller resections using hang-back, nonadjustable sutures. Pre- and postoperative incomitance was compared using the paired t test.

RESULTS

A total of 16 adults were studied (mean age at surgery, 49.3 ± 17.5 years), 12 with incomitant vertical deviations and 4 with incomitant horizontal deviations. Eight patients had preoperative deviations of <2Δ in primary gaze (mean, 9.2Δ ± 10.5Δ; range, 1Δ-35Δ). The mean maximum eccentric gaze deviation was 21.4Δ ± 9.9Δ (range, 10Δ-48Δ). Postoperatively, 12 patients (75%) had a decrease in incomitance of >50%, and all had expansion of the field of binocular single vision. Improvement in postoperative incomitance was highly statistically significant in the vertical incomitant group (P < 0.0001) but not statistically significant in the horizontal group (P = 0.39). The technique corrected downgaze deviations in 4 patients with canine tooth syndrome (93% ± 3.3, P < 0.0001) without worsening the hypotropia in upgaze.

CONCLUSIONS

Combined resection-recession single muscle surgery significantly reduces incomitance with minimal effect on primary gaze. It is most effective for treating vertical deviations worse on downgaze with primary gaze deviations of <2Δ and for canine tooth syndrome; the technique was less successful in reducing horizontal incomitance and in cases involving gaze palsies and nystagmus.