Different Factors Influencing Distance Stereoacuity In Intermittent Exotropia

Objective:This study was conducted to identify the relationships between stereoacuity,age,control grade and angle of deviation in intermittent exotropia,to assess the postoperative outcomes among groups and finally evaluate the timing of surgery.Methods:This prospective study involved 79 basic intermittent exotropia patients who underwent strabismus surgery and completed at least ten weeks of follow-up.The 79 patients were divided into three subgroups according to their age/control grade /angle of deviation.Statistical analysis was performed using SPSS statistical software(SPSS,Inc.,Cary,NC).A P-value of less than 0.05 was regarded as statistically significant.The measurements included motor control,ocular deviations,random-dot stereograms,and ocular deviations after occlusion.The last three measurements were examined preoperatively and postoperatively at two and ten weeks.Results:Positive correlation was found between age and distance stereoacuity(p < 0.05).As to deviation angle and far stereoacuity,we can also find a positive correlation between them(p < 0.05).Partial correlation coefficient for control grade and distance stereoacuity is positive(p < 0.05),and is higher than the other two above.Multiple linear regression formula was built successfully(sig=0.000<0.005,F=39.009>0.001).Among 79 patients,the distance stereoacuity of 26(32.9%)patients became normal two weeks after surgery ofintermittent exotropia,while almost 57(72.2%)patients became normal ten weeks postoperatively.There were statistically significant differences between groups(p < 0.05).There are also significant differences between distance stereoacuity of nine subgroups(p<0.05).In each subgroup,the median distance stereoacuity improved significantly after two and ten weeks compared with before(p <0.05).Conclusions:Distance stereoacuity of 79 X(T)patients were improved two and ten weeks postoperatively in each subgroups.All the three factors have influences to distance stereoacuity.Among them,control grade has more influence than the other two.Better control grade was significantly accompanied by better distance stereoacuity.The distance stereoacuity of most patients can become better even delayed their age older than 13.Patients with deviation angle bigger than 60 PD have a lower rate of recover.When patients are able to control their eye position,their distance stereoacuity can still increase.