AIM:To discuss the clinical features and operation methods on small-diopter intermittent exotropia.

METHODS:Totally 206 in-patients with small-diopter intermittent exotropia(IXT)in different operation groups, from September 2013 to September 2014,were observed for the eyesight, refraction, dominant eye, exotropia degree, synoptophore and near stereopsis before and after operation. Three types were divided in 206 cases. One hundred and thirty-two cases of basic IXT were the first type, in which 52 cases underwent nondominant eye unilateral recess-resection(nondominant eye unilateral recess-resection, ndR& R), 40 cases underwent dominant eye unilateral recess-resection(dominant eye unilateral recess-resection, dR& R), 40 cases underwent bilateral lateral rectus recession(bilateral lateral rectus recession, BLR-rec). Sixty-one cases of convergence insufficiency IXT were the second type, in which 40 cases underwent ndR& R, 21 cases underwent bilateral medial rectus amputation. Thirteen cases of divergence excess IXT were the third type, in which 7 cases underwent ndR& R, 6 cases underwent BLR-rec. The rates of the orthophoria, undercorrection, overcorrection and the recovery of synoptophore and near stereopsis after surgery in 1, 6, 12, 24mo were compared in 3 types.

RESULTS: The clinical features of 206 cases with small-diopter IXT were: in the most cases, between 5 and 12 years old; nondominant eye was left eye; the eyesight of nondominant eye was lower than another eye; refraction status were myopia, astigmatism and anisometropia; basic IXT was the most common type; exotropia degree was between 40^△ and 60^△; some cases owned binocular function and near stereopsis. Comparison of operation methods in 3 groups: orthophoria comparisons in basic IXT among ndR& R group, d R& R group and BLR-rec group were significant difference(P<0.05)after operation in 12 and 24mo. Orthophoria comparison in insufficiency IXT between ndR& R group and BMR-amp group was not significant difference(P>0.05)after operation. The operation of divergence excess IXT was effective. Orthophoria comparison in ndR& R group between basic IXT and convergence insufficiency IXT was significant difference(P<0.05)after operation in 6, 12 and 24mo. Synoptophore and near stereopsis of some cases were improved after operation.

CONCLUSION:Early surgical treatment of the pediatric patients with small-diopter IXT is benefit for the establishment of binocular function and stereopsis. Adult surgical treatment can improve the appearance and alleviated eyestrain. In 206 cases, the operation method of ndR& R is obvious curative effective in each type of small-diopter IXT. The operation methods of BMR-amp and BLR-rec are obvious effective in insufficiency intermittent and divergence excess IXT.