Effectiveness of Surgical Treatment for Dissociated Vertical Deviation with Different Clinical Characteristics

Abstract

Objective: To investigate the effectiveness of surgery for dissociated vertical deviation (DVD) with different clinical characteristics. Methods: A retrospective study was conducted on 49 patients who underwent surgical correction for DVD at Qingdao Eye Hospital of Shandong Eye Institute from January 2013 to December 2016. Patients were divided into four groups according to their angle of vertical deviation. Different surgical designs were used, and surgical efficacy was analyzed. In group A, the deviation angle was ≥20△ in both eyes of 18 patients with a difference of <5△. In group B, the deviation angle was ≥20△ in both eyes of 14 patients with a difference of ≥5△. In group C, 17 patients had a large deviation angle ≥20△ in one eye and a small deviation angle <5△ in the other eye. Small vertical strabismus (<5△) meant a slight rotation or no vertical strabismus. Group C was divided into group C1 and group C2 based on different surgical methods used. A 7-to-10 mm recession of the superior rectus muscle was reserved for patients in group A. A 7-to-10 mm recession of the superior rectus muscle was reserved for eyes with a large vertical angle and a 5-to-6 mm recession of the superior rectus muscle was reserved for the other eyes in group B. A 7-to-10 mm recession of the superior rectus muscle was reserved for eyes with a large vertical angle, and a 4 mm recession (10 patients) was reserved in group C1, or no surgery (7 patients) was performed on eyes with a small deviation angle in group C2. Results: No eyelid retraction was observed after large recessions of the superior recuts muscle. The rate of surgical satisfaction was 94% in group A and was 93% in group B. Among the patients with bilateral surgeries in group C1, the rate of surgical satisfaction was 100%. Among the patients with unilateral surgical treatment in group C2, the rate of surgical satisfaction was 29%. There was a statistically significant difference between group C1 and group C2 (Z=-3.656, P<0.001). Conclusions: For DVD, usually a binocular disease, bilaterally equal or unequal recession of the superior rectus muscle could be reserved according to the symmetry or asymmetry degree of vertical strabismus. A 4 mm recession of the superior rectus muscle may be reserved in the preferred eye of patients with a small vertical angle or no vertical strabismus. If the non-preferred eye with a large vertical angle is operated on, the preferred eye with a small vertical angle may show obvious vertical strabismus or a new compensatory head position. Key words: dissociated vertical deviation; surgical correction; recession of the superior rectus