Clinical Characteirstics And Clinical Analysis Of Surgical Treatment Of A And V Pattern Strabismus

Objective：This study is aimed at investigating the clinical features and surgicaltreatment and evaluating the effects of different surgical procedures of A-V pattern.Methods：The clinical data of383patients with A-V pattern in our department ofpediatric ophthalmology between January2009and January2012were summarizedretrospectively, in order to analysis the case clinical features and the surgical treatment andto evaluate the effects of different surgical procedures of A-V patternResults：(1)383patients of A-V pattern strabismus accounts for13.9%of allstrabismus。193patients are of A pattern (A-pattern exotropia162, A-pattern esotropia31),and106are with overaction of superior oblique muscle (47patients of bilateral superioroblique muscle overaction,19patients of unilateral superior oblique muscle overaction)。98eyes of51patients underwent superior oblique myectomy (47patients underwent bilateralsuperior oblique muscle myectomy,4patients underwent unilateral superior oblique musclemyectomy), the superior oblique muscle overaction in the91eyes disappearedpostoperatively. Only7eyes manifested+1residual superior oblique muscle overaction。Theleft55patients which did not undergo superior oblique muscle myectomy due to various ofreasons were performed vertical offsets of the horizontal rectus or the horizontal strabismussurgery only，the situation of the overaction of the oblique muscle was as before. There areV-pattern190patients (V-pattern exotropia167,V-pattem esotropia23), of which149arewith overaction of superior oblique muscle (117of bilateral inferior oblique muscleoveraction,32of unilateral inferior oblique muscle overaction).205eyes of121patientsunderwent inferior oblique myectomy (84patients underwent bilateral inferior obliquemuscle myectomy,37patients underwent unilateral inferior oblique muscle myectomy), theinferior oblique muscle overaction in the196eyes disappeared postoperatively.Only9eyes manifested+1residual inferior oblique muscle overaction。The left28patients whichdid not undergo inferior oblique muscle myectomy were performed vertical offsets of thehorizontal rectus or the horizontal strabismus surgery only，the situation of the overaction ofthe oblique muscle was as before. (2) the effects of different surgical procedures of A-V pattern. A-pattern patients:47patients underwent bilateral superior oblique muscle myectomy：the mean of A patterndeviation was (22.25±11.89)~△preoperatively, whereas it became (1.48±5.84)~△postop-eratively, resulting in an (21.07±7.13)~△decrease in deviation，2patients showed a residual Apattern，The success rate was95.7%;4patients underwent unilateral superior obliquemyectomy：The average of A pattern was (14.25±2.63)~△before and (-0.25±11.89)~△after theoperaten, success rate achieved a collapse of A pattern to less than10D in100%of patients.35patients underwent vertical offsets of the horizontal rectus：The average A pattern was(21.40±7.04)~△before and (6.65±6.49)~△after the operaten, success rate achieved a collapseof A pattern to less than10to71.4%.V-pattern patients:84patients underwent bilateral inferior oblique muscle myectomy：the mean of V pattern deviation was (-27.37±9.36)~△preoperatively, whereas it became(-6.52±6.66)~△postoperatively, resulting in an (-20.85±9.19)~△decrease in deviation;9patients showed a residual V pattern，The success rate was89.3%;37patients underwentunilateral inferior oblique muscle myectomy：The mean of V-pattern collapse decreased from(-20.57±5.38)~△to (-5.17±4.22)~△，resulting in an (-15.39±4.38)~△decrease in deviation.4patients showed a residual V pattern，The success rate was89.2%;34patients underwentvertical offsets of the horizontal rectus：the mean of V pattern deviation was (-26.0±6.71)~△，preoperatively, whereas it became (-9.78±4.48)~△postoperatively, resulting in an(-16.21±6.99)~△decrease in deviation,5patients showed a residual V pattern，The successrate was85.3%.The three surgical procedure above could effectively treat the A-V pattern.(3) Of all190V pattern patients,37patients underwent unilateral inferior obliquemuscle myectomy.It could be divided into two situation:29patients showed markedasymmetry in the degree of inferior oblique overaction, and the vertical deviation is large inthe primary position. the oblique muscle myectomy operaten was performed in the moreoveracting inferior oblique. The average of preoperative hyperdeviation was11.6~△.And thiswas reduced to3.7~△postoperatively.Statistical significance was achieved between pre-andpost-operaten（t=4.617，p<0.001）.4patients showed a residual V pattern，The success ratewas86.2%;The second situation:8patients who had unilateral overacting inferior obliquemuscles of2units or more but with bilateral extortion of the fundus photography underwent unilateral inferior oblique muscle myectomy, of which only one patient had residualoveraction of inferior oblique,with no residual V pattern.(4) There were83A-V pattern patients combined with large degree of the horizontalstrabismus,and62A-V pattern patients collapsed postoperatively;whereas21A-V patterncollapsed in59patients with low degree of the horizontal strabismus.(χ2=21.715， P<0.01)(5) In the study of193A pattern patients, There are106patients with SOOA (184eyes),the fundus photography of142eyes showed incyclotropia.98eyes underwent obliquemuscle myectomy. of87eyes collapse incyclotropia postoperatively.11eyes showed aresidual incyclotropia.The left55patients underwent vertical offsets of the horizontal rectusor the corection of the horizontal strabismus only, fundus photography of the left patientsremained the same as before. In the190V pattern cases,there are149patients with IOOA(233eyes), fundus photography of220eyes showed excyclotropia.205eyes underwent IOmyectomy,87eyes collapse excyclotropia after operaten.22eyes showed a residualincyclotropia.The left28patients underwent vertical offsets of the horizontal rectus or thecorection of the horizontal strabismus only, fundus photography of the left patientsremained the same as before.(6) Regardless of the myectomy of the oblique muscle and the vertical offsets of thehorizontal rectus, the patients combined with horizontal strabismus were treated,meanwhile,the A-V pattern surgery was performed.In86A pattern patients, satisfactory horizontal alignment (within10~△) was achieved in78patients (90.7%).In155V pattern patients: satisfactory horizontal alignment (within10~△)was achieved in143patients (92.3%).In142patients who underwent horizontal strabismusonly, satisfactory horizontal alignment (within10~△) was achieved in128patients(90.1%),there were no statistic difference between each group.Conclusions:1The A-V pattern strabismus commonly occurs clinically,and V-patternexotropia is the most common type in strabismus，the other is the A-pattern exotropia. Fromits etiology,the main reason is oblique muscle Dysfunction. We choose which surgicalprocedure to take according to whether having oblique muscle overaction、the degree ofoveraction and binocular vision or not. This study performed bilateral oblique musclemyectomy、 unilateral oblique muscle myectomy and vertical offsets of the horizontal rectussurgery. All the results are satisfied. 2As to the A-V pattern patients who are of overaction of the bilateral oblique muscleasymmetric, combined with hyperdeviation in primary position of eye,we can performmyectomy of the unilateral oblique muscle.The advantage is not only the A-V pattern canbe treated but also hyperdeviation in primary position of eye can be solved.Besides, it didnot lead to the oblique muscle overaction in the contralateral eye.3Patients with Large degree of the horizontal strabismus, if they are not combinedwith oblique muscles dysfunction，different operatens can be designed according to thedegree of the horizontal strabismus. The result is part of patients’ A-or V-pattern candisappear with horizontal strabismus solved.4Fundus photography combined with ocular movement Examination can giveguidance to the choice of surgery as well as value the effect of surgery.5The patients combined with horizontal strabismus were treated at the same timewhen the A-or V-pattern surgery performed, The influence of the oblique muscle to theprimary directions will not be considered when designing the operaten.