The Study Of Re-establishment Of Binocular Vision And The Impact Factors In Adults After Exotropia Surgery

ObjectiveTo study the re-establishment of binocular vision and the impact factors in adults after exotropia surgery. MethodsFifty-six adult patients with exotropia were divided into 2 groups, based on the age of onset, of before visual maturity(BVM, <9 years old) and after visual maturity(AVM, ≥9 years old). Binocular vision, both distant and near, was checked before and 6 weeks after surgery with a synoptophore and Yan’s digital stereogram. ResultsThe rebuilding rate of distance binocular vision was as follows. For grade I binocular vision, it was 77% in the AVM group, significantly higher than the BVM group(33%; x~2=10.240, P<0.01). For grade II, ti was the same with grade I. For grade III, it was 47% in the AVM group and 17% in the BVM group. Differences between the two groups were statistically significant(x~2=5.400, P<0.05). The rebuilding rate of near binocular vision was 73% in the AVM group, which was significantly higher than the BVM group(29%; x~2=10.461, P<0.01). In group AVM, there were 22 cases of near stereo vision, 6 cases of peripheral stereo vision, 4 cases of macular stereo vision, 12 cases of central concave stereo vision(40%). There were 7 cases of BVM group and 5 cases of peripheral stereo vision, 2 cases of macular stereo vision. Patients with strabismus type group: 16 cases of intermittent exotropia, postoperative far stereo vision reconstruction 7, reconstruction rate of 44%; constant exotropia in 38 cases, postoperative reconstruction of 11 patients, reconstruction rate of 29%;The reconstruction rate of far stereo vision had no significant difference(x~2=1.110, P > 0.05) in the intermittent and constant group. There are 9 patients with near stereo vision reconstruction in intermittent strabismus group, the reconstruction rate was 56%. There are 12 patients in the constant strabismus group, the rate of reconstruction was 32%, the difference between the 2 groups was not statistically significant(x~2=0.089, P>0.05). The logistic analysis showed that the age of onset and operation is the important factors affecting the re-establishment of the postoperative distance(OR=6.046, P<0.05; OR=0.140, P<0.01)and near(OR=10.825, P<0.05;OR=0.189, P<0.05)stereopsis. The type of exotropia and the degree of the preoperative strabismus had no maked influences on the binocular vision. ConclusionsSurgical correction of adult exotropia was helpful in the re-establishment of the binocular visual functions and beneficial to obtain a certain degree of stereopsis. The re-establishment of the distance stereopsis was associated with the age of onset and the age of operation. The age of onset played a key role in getting stereopsis.There was no significant effect on the binocular visual reconstruction after the type of strabismus and the degree of strabismus. In order to improve the postoperative binocular vision, surgery could be performed as early as possible for adult exotropia patients.