Clinicalanalysis Of Modified Yokoyama Surgical Treatment For Myopic Strabismus Fixus

Purpose:To evaluate the efficacy of modified Yokoyama surgical procedure for myopic strabismus fixus.Methods:Retrospective analysis of 7 patients(10 eyes)with myopic strabismus fixus who had been operated in our hospital from 2012 to 2016.The clinical data,imaging data and surgical methods were analyzed.The axial length of the patient was measured with A-scan echography.The anatomic variations of eyeball’s position and the extraocular muscles were examined by orbital CT scan or MRI.Pre-and intraoperative forced ductions test were used to determine the degree of limitation.The nine diagnostic eye positions were performed beforeand after operation.The surgical treatment was medial rectus muscle recession combined with modified Yokoyama procedure.Results:7 patients(10 eyes)with myopic strabismus fixus,3 females and 4 males.The age of onset ranged from 11 to 59 years old.The average age was 37.1±18.6 years old.The average axial length was 31.22 ± 2.00 mm.CT or MRI examination of the orbit showed that the lateral rectus muscle was shifted to the inferior side,and the superior and inferior rectus muscle were shifted to the nasal side,and the eyeball at downward and inward position.Preoperative forced ductions test showed that all of the patients were strong positive.There were still some changes of eye position in the early stage after operation,as time went on,the eye position could be further improved,and the eye position was stable at 6 weeks after operation.In the early stage,the eye movement was still not in place or the improvement was not obvious,and the eye movement could be further improved over time,and it was still changed in 1 year after operation.Postoperative visual acuity of 7 patients were higher than that before operation.2 cases with binocular diseases who were accepted binocular surgery simultaneously had significant improvement in eye position and eye movement.Whereas,2 patients with binocular diseases who only underwent one eye surgery or eyes successively surgeries,they performed partial internal deviation and poor eye movement.Postoperative follow-up period ranged from 2 monthsto 55 months,averaged 24.0 ± 16.2 months.There was no postoperative complications.The curative effect of all patients were stable.Conclusion:The modified Yokoyama surgery for myopic strabismus fixus can get better clinical efficacy.It can not only improve the appearance of patients,but also restore the vision and improve the eye movement.For those patients who illed with both myopic strabismus fixus,surgery should be carried out on both eyes simultaneously.