AIM: To quantitatively evaluate the therapeutic efficacy of the asymmetric recession of bilateral lateral rectus in patients with unilateral type III Duane retraction syndrome.

METHOD:Retrospective analysis of clinical data. The clinical data of 12 cases of type III Duane retraction syndrome with unilateral lateral rectus recession were analyzed. All subjects had restricted internal rotation, with narrowing of the palpebral fissure and vertical deviation, and restricted external rotation with widening of the palpebral fissure. All patients had abnormal head positions. The degree of strabismus was measured while maintaining the head in a neutral position. Asymmetric recession of bilateral lateral rectus was selected based on the degree of strabismus of affected eye or 1～3mm longer, with a smaller recession and Y-splitting in the affected eye and a larger recession in the healthy eye.

RESULT:The difference in the degree of strabismus in the healthy eyes before and after surgery was statistically significant(Z=-4.158, P<0.01), as was the difference in the degree of restricted internal rotation(Z=-2.640, P=0.008). The difference in the degree of restricted external rotation was not statistically significant(Z=-1.732, P=0.083). The difference in abnormal head position was statistically significant(Z=-4.181, P<0.01), while the difference in eyeball recession was not statistically significant(Z=-1.414, P=0.157). The difference in vertical deviation was statistically significant(Z=-3.115, P=0.002). A total of 10 patients(83%)had stereoscopic vision before surgery, and 11 patients(92%)had recovered stereoscopic vision after surgery, with a further improvement in stereoacuity in 50% of patients.

CONCLUSION:Asymmetric recession of bilateral lateral rectus combined with Y-splitting of the affected lateral rectus can effectively improve the degree of strabismus, abnormal head position, vertical deviation and stereoacuity without aggravating the degree of restriction of external rotation or eyeball recession.