The Resection of Extraocular Muscle without Scleral Suture in the Rabbit

ABSTRACT

PURPOSE: The purpose of this study was to find stability and histological change after resection of extraocular muscle by suturing the proximal and distal muscle segments end to end for elimination of the risk of scleral perforation in the rabbit. METHODS: After dividing rabbits into two groups, we performed the resection of superior rectus muscle. The control group (18 eyes) was treated with conventional operation method in which we placed sutures directly into sclera after resection of muscle, whereas in the experimental group (18 eyes) sutures were placed between proximal and distal muscle segments end to end, without scleral suture, after resection of muscle 3 mm behind the original insertion. We measured the maximum adhesion power at 1day, 1-, 4-, and 8-week postoperative intervals and observed the histopathologic findings at 4- and 8-week postoperative intervals in both groups. RESULTS: In both groups, the maximal adhesion power increased gradually with time at muscle-to-sclera and muscle-to-muscle adhesion site and reached its highest at 8th week. According to histopathologic findings, chronic inflammatory reaction and foreign body reaction were more severe in the experimental group at 4th week, but disappeared at 8th week in both groups. Fibrosis was slightly more severe in the experimental group. CONCLUSIONS: In resection of extraocular muscle for correction of strabismus, muscle-to-muscle suture is thought to be stable and effective way to avoid scleral perforation for the patient whose sclera is thin or abnormal.