외사시로 한눈 혹은 두눈 외직근후전을 받은 후 재발한 외사시의 한눈 내직근절제술의 효과

The Effect of Medial Rectus Resection in Reccurent Exotropia After Lateral Rectus Recession

Purpose: To investigate the effect of unilateral medial rectus resection in recurrent exotropia under 25 Prism Diopter after unilateral or bilateral lateral rectus recession. Methods: A retrospective chart analysis was conducted for 21 patients who underwent unilateral medial rectus resection for recurrent exotropia under 25PD and uni- or bilateral lateral rectus recession for prior surgery of exotropia. The medial rectus was resected from 5.0 to 7.0 mm by 0.5 mm according to angle deviation at a distance. The postoperative deviated angle was checked at one week, three months and six months postoperatively to investigate the amount of corrected deviation per resected muscle. Results: The average preoperative deviation was 20.57±3.37PD. We resected mean 6.1±0.62 mm of the medial rectus. At one week after the surgery, the postoperative deviated angle was 2.00±4.32PD, After six months it was 6.57±7.40PD, and there appeared to be an increase of deviation. Ten patients (48%) fused before surgery and 12 (57%) after surgery. The corrected deviation per resected muscle was 2.88±1.08PD. Conclusions: Unilateral medial rectus resection is an effective surgical method for the treatment of recurrent exotropia under 25 PD after lateral rectus recession.