The Clinical Analysis On Bilateral Late Ral Rectus And Broken Tendon Inferior Oblique For The Treatment Of Converg Ence Insufficiency Type Exotropia Merg E Inferior Oblique Overaction

Objective:To determine the efficacy of convergence insufficiency type exotropia with inferior oblique overaction treated by surgery of combination of bilateral lateral rectus recession and inferior oblique tenotomy.Methods:In this retrospective study,all 44 patients with convergence insufficiency type exotropia and inferior oblique overaction underwent bilateral lateral rectus recession and inferior oblique muscle tenotomy and then followed at least 6 months from January 2013 to June 2014.Before operation, some examinations would be performed, such as visual acuity, fixation, refractive state, extropia angle on 33 cm and 6m,dynamic stereoscopic vision, simultaneous perception, fusion and stereopsis. Follow-up examinations ocular alignment, stereopsis, strabismus degree. Results:The success rates of postoperative 1～3days and 6months was respectively 88.6% and 77.2%.Compard with preoperative group, exotropia degree decreased significantly in both near and far distance inpostoperative group(t=-32.010, t=-28.764, t=-21.815, t=-19.114, P=0.000 , P=0.000, P=0.000, P=0.000,P<0.05).Additionally,after postoperative 6months,dynamic stereoscopic vision, simultaneous perception, fusion and stereopsis were significantly improved when compared with that of preoperation group (χ2=11.636,χ2=15.006,χ2= 20.230, x2=2.928,P=0.000, P=0.000, P=0.000, P=0.003,P<0.05).The fusion scope was significantly expanded after surgery in those patients who have preoperative fusion(t=5.417,P=0.000,P<0.05).There were no difference between the success rate and age(x2=0.010, P=0.920, P>0.05).However, the stereoscopic vision recovery rate in 4-11 years group was significantly higher when compared with that 12-29 years group(x2=4.358, P=0.037, P <0.05).Conclusions:The combination of bilateral lateral rectus recession and inferior oblique tenotomy is a safe and effective procedure in the treatment of convergence insufficiency type exotropia. Fusion and senior stereoscopic vision can be improved obviously after surgery. In addition, the age, as an important factor, could affect postoperative recovery and reconstruction of binocular vision.