METHODS: A prospective study of 139 patients with intermittent exotropia admitted to our hospital from May 2014 to December 2016 was conducted. Patients were divided into three groups according to their ages: Group A with 58 cases aged between 3 and 7 years old, Group B with 41 cases aged from 8 to 12 years old and Group C with 40 cases aged more than 12 years old. The therapeutic effect of each group was observed.

RESULTS: The postoperative orthographic rate between the three groups at 3d, 1, 3 and 6mo postoperatively had statistical differences(P<0.05). The postoperative orthographic rate of Group A was significantly higher than that of the other two groups at different time points(P<0.05). The postoperative orthographic rate of of Group B at 3d and 1mo after operation was significantly higher than that of Group C(P<0.05). After operation, the stereoscopic function of each group at 6mo postoperatively was significantly improved, and the statistical difference between the groups was significant(P<0.05). The proportion of patients with stereopsis recovered in Group A was significantly higher than those in Groups B and C(P<0.05). There was no significant difference in the preoperative strabismus degree between either two groups(P>0.05), while the degree of strabismus in each group after 6mo was significantly different(P<0.05). And the proportion of strabismus ≤30^△ in Group A was higher than the other two groups(P<0.05). The changes of BCVA among the three groups after operation had significant differences(P<0.01). The BCVA of Group A was better than the other two groups at 3d, 1,3 and 6mo after operation(P<0.05). There were no significant differences between BCVA of 3mo and 6mo after operation in each group(P>0.05). There was a statistically significant difference in the incidence of ocular regression rate in three groups during the 6mo follow-up(P<0.05); that of Group A was lower than Group B and Group C(P<0.05)and Group B were lower than Group C, and the statistical difference between groups was significant(P<0.05).

CONCLUSION: The surgical type of the intermittent exotropia should be based on the classification of strabismus, which can promote postoperative recovery of the eye position and visual function, improve visual acuity, and then avoid ocular regresses.