| Objective: To explore the sugery opportunity and efffect of intermittent exotropia. To investigate the rebuilding of the stereoacuity in intermittent exotropia patient and the related factors affecting the stereoacuity before and after operation.Methods: 42 cases of intermittent exotropia which were treated in March, 2007 to October, 2007 were analysed retrospectively. Patients were categorized according to the ages, types of operation, types of strabismus, stereopsis and fusion function before operation. The 25 male and 17 female patients had an average age of 10.2±4.3 years at the time of surgery. 17 patients from 5～7 years, 25 patients from 8～21 years. The type of divergence excess included 16 patients, the basic pattern included 19 patients and the convergence insufficiency included 7 patients. There were 30 patients with the faction of fusion and 12 patients without it before operation. Exclusion criteria were preoperative amblyopia, co-existent ocular disease, previous strabismus surgery, vertical strabismus and nystagmus. People who had neurologic or severe systemic disease and patients with a paralysis of convergence and accommodation also were excluded. All of cases took the examination of visual acuity, optometry and fit the glasses, prism test, eye movement, synoptophore check patients'visual function of double eyes. Patients of intermittent exotropia who had binoculus corrected visual acuity over 0.8, anisometropi was under 1.5D and strabismus degree over -15△were included in the research cases. Cases which strabismus degree was under -25△were took recession of single eye lateral rectus muscles. Cases of strabismus degree between -25△to -50△were took recession of double eyes lateral rectus muscles. Cases of strabismus degree over -50△were took recession of double eyes lateral rectus muscles and tenotomy of single eye medial rectus muscles. All of cases were followed up 1 year. Curative effect of these groups was compared.Results: 42 cases of intermittent exotropia's postoperative eye positions were orthophoria in 34 cases (81%), undercorrection in 5 cases (11.9%) and overcorrection in 3 cases (7.14%). 19 patients (45.2%) had stereopsis before operation, after surgical correction, 29 patients (69.2%) had stereopsis. 1 The patients of 5～7 years group were 17 cases, their postoperative eye positions were orthophoria in 14 cases (82.4%), undercorrection in 2 cases (11.8%) and overcorrection in 1 cases (5.9%). The patients of 8～21 years group were 25 cases, their postoperative eye positions were orthophoria in 20 cases (80%), undercorrection in 3 cases (12%) and overcorrection in 2 cases (8%). There was no significantly differences between two groups (χ2=0.0363 P=0.8488>0.05). 2 Recession of single eye lateral rectus muscle operated in 6 patients, and their postoperative eye positions were orthophoria in 5 cases (83.3%), undercorrection in 1 cases (16.6%) and none of them had been overcorrected. Bilateral lateral rectus muscle recession operated in 29 patients, and their postoperative eye positions were orthophoria in 25 cases (86.2%), undercorrection in 3 cases (10.3%) and overcorrection in 1 case (3.4%). Bilateral lateral rectus muscle recession and unilateral medial rectus muscle resection operated in 7 patients, and their postoperative eye positions were orthophoria in 4 cases (57.1%), undercorrection in 3 cases (14.3%) and overcorrection in 2 cases (28.6%). There was no significantly differences between three groups (χ2=3.1149 P=0.2107>0.05).3 The type of divergence excess were 16 cases, their postoperative eye positions were orthophoria in 14 cases (87.5%), undercorrection in 1 cases (6.3%) and overcorrection in 1 cases (6.3%). The basic pattern were 19 cases, their postoperative eye positions were orthophoria in 15 cases (78.9%), undercorrection in 3 cases (15.7%) and overcorrection in 1 cases (5.3%). The convergence insufficiency were 7 cases, their postoperative eye positions were orthophoria in 5 cases (71.4%), undercorrection in 1 cases (14.3%) and overcorrection in 1 cases (14.3%). There was no significantly differences between three groups (χ2=0.9062 P=0.6357>0.05).4 30 cases with the function of fusion before operation, 28 cases (93.3%) were orthophoria, undercorrection in 1 cases (3.3%) and overcorrection in 1 cases (3.3%). 12 cases had the absence of fusion before operation, 6 cases (50%) were orthophoria, undercorrection in 4 cases (33.3%) and overcorrection in 2 cases (16.7%). The differences between two groups was statistically significant (χ2=10.4383 P=0.0012<0.01).5 Patients who with the function of fusion and without the function of stereopsis before operation were 11 cases, 6 cases recovered their stereopsis, the recovery rate is 72.7%. 12 cases had the absence of fusion before operation, 2 cases recovered their stereopsis, the recovery rate is 16.7%. The differences between two groups was statistically significant (P=0.0123<0.05).6 The patients of 5～7 years group were 8 cases without the stereoscopic vision, 6 cases (75%) of them recovery the stereoscopic vision. The patients of 8～21 years group were 15 cases without the stereoscopic vision, 4 cases (26.7%) of them recovery the stereoscopic vision. There is statistical meaning in the difference between them (P=0.0393<0.05).Conclusion:1 The orthophoric rate did not correlate with intermittent exotropia patients'ages, types of operation, types of strabismus.2 Patients who had the presence of fusion preoperative had a higher success rate in orthophoria than the others. The fusion faction is quite an effect on the postoperative eye position.3 Patients who had the presence of fusion preoperative had a higher success rate in stereopsis than the others. The presence of fusion is a good factor for binocular vision rebuilding.4 The orthophoric rate did not correlate with intermittent exotropia patients'ages, but the younger the patients′mean age was, the higher the recovery rate of the stereoscopic vision was. From the point of stereopsis rebuilding, the surgical correction for intermittent exotropia should be performed as early as possible and the achievement of functional cure. |
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