Clinical observation of superior rectus transposition with/without augmented suture and vertical rectus transposition for the treatment of strabismus caused by complete abducens nerve palsy

Abstract

Objective: To evaluate the efficacy and safety of superior rectus transposition (SRT) with/without augmented suture and vertical rectus transposition (VRT) for the treatment of strabismus caused by complete abducens nerve palsy. Methods: This was a retrospective cohort study. Forty-two patients (42 eyes) with complete abducens nerve palsy underwent strabismic surgeries from January 2015 to November 2020 in Tianjin Eye Hospital. According to the different procedures, the patients were divided into three groups: SRT group (16 cases, SRT with medial rectus recession), superior rectus transposition with augmented suture (SRTA) group (13 cases, SRT with Buckley suture and medial rectus recession) and VRT group (13 cases). The preoperative and postoperative (1, 6 and 12 months) data including deviations, ocular motility, binocular vision and surgical complications among three groups were analyzed and compared. χ2 test was used for comparison of count data among three groups. The measurement data were compared among three groups by the repeated measures ANOVA. LSD-t test was used for within-group comparison and between-group comparison. Results: There was no difference in sex ratio, age and course of disease among the groups (all P>0.05). The horizontal deviations of the three groups at 1, 6 and 12 months after surgeries was lower than that before surgeries, and the difference was statistically significant (all P<0.001). The horizontal deviations of the SRT group, SRTA group and VRT group at 12 months after surgeries were (+0.8±5.8), (+0.8±4.5), (+1.2±2.5) prism diopters (PD), respectively, lower than that of the preoperative (+82.8±17.2), (+77.7±26.1), (+71.5±18.6) PD. However, there was no significant difference among different postoperative follow-up timepoints (all P>0.05). There was no difference in horizontal deviations before surgeries and at 1, 6 and 12 months after surgeries among three groups (P>0.05). There were significant differences in the scales of abduction motility among preoperative, postoperative 1, 6 and 12 months measurements for three group (all P<0.001). The scales of abduction before surgeries in the SRT group, SRTA group, and VRT group were (-4.4±0.5), (-4.4±0.5), (-4.5±0.5) scale and at 12 months after surgeries were (-2.3±0.7), (-2.2±0.5), (-2.1±0.6) scale respectively. But there was no change among different postoperative follow-up timepoints (all P>0.05). Preoperative and postoperative 1-, 6-and 12-month abduction motility was similar among three groups (P>0.05). There were significant differences in the scales of adduction limitation among preoperative, postoperative 1-, 6-and 12-months measurements for three group (all P<0.05). But there was no change among different postoperative follow-up timepoints (all P>0.05). There were significant differences between the SRT group [(-0.9±0.6), (-0.8±0.6) scale] and the SRTA groups [(-1.5±0.5), (-1.4±0.5) scale] (t=-2.62, -2.52) and between the SRTA group and the VRT group [(-0.8±0.8), (-0.6±0.7) scale] (t=2.62, 3.01) at 6 and 12 months after surgeries (all P<0.05). The outcomes of binocular vision at postoperative 12 months were similar among three groups (P>0.05). No patient had torsional diplopia and anterior segment ischemia. Only 2 patients from the SRTA group had hypotropia of 4 to 5 PD in the primary position associated with supraduction limitation. Conclusions: SRT with/without augmented suture and VRT are effective and safe procedures for the treatment of strabismus caused by complete abducens nerve palsy. They could correct deviations, improve abduction motility and restore binocular vision, with stable outcomes and a small risk of vertical and torsional diplopia.