Abstract
Purpose: :
To describe the efficacy of a relaxed muscle technique for the treatment of strabismus secondary to thyroid eye disease (TED).
Methods: :
Retrospective review of 63 consecutive patients with TED who underwent relaxed muscle positioning technique strabismus surgery between 1999 and 2009. The extent of recession was determined by marking the position of the disinserted tendon as it rested freely on the globe in primary position. The muscle was sutured to the globe at the mark. All patients had post-inflammatory TED for at least three months before surgery. Surgery was not performed within the first three months after orbital decompression. 62/63 had at least two months of post-operative follow-up. Surgical outcomes at two, six, and twelve months were recorded, as were the outcomes of any subsequent strabismus surgeries. Regression analysis was performed to determine if there was a dose-response relationship between the amount of recession and the pre-operative deviation. A re-operation rate was determined, and the reasons for re-operation were analyzed. Excellent outcomes were defined as having no diplopia in primary and reading gazes without prisms; good outcome was defined as no diplopia in primary and reading positions with <10 diopters of prism in glasses; poor outcome was defined as persistent diplopia in primary or reading positions despite prisms, or the inability of the patient to tolerate the necessary prisms.
Results: :
Patients ranged in age from 21 to 77 years. 62/63 had diplopia pre-operatively. Only one had prior strabismus surgery. 40 had prior orbital decompression. 23 had diplopia and no history of decompression, 23 had diplopia prior to decompression, and 16 had diplopia only after decompression. 51 patients (81%) underwent only one surgery, nine (14.3%) underwent two surgeries, and three (4.8%) patients underwent three surgeries. 51 (81%) patients had excellent outcomes, ten (15.9%) had good outcomes, and two (3.2%) had poor outcomes. Regression analysis failed to reveal a correlation between the pre-operative deviation measurements and the amount of recession performed in millimeters, even when the linear analysis was restricted to cases with excellent outcomes after one surgery (R2=.640 for horizontal deviations, R2=.318 for vertical deviations). There were no surgical complications.
Conclusions: :
The Intraoperative Relaxed Muscle Positioning Technique provides predictable good or excellent ocular alignment and relief from diplopia in most patients with dysthyroid strabismus.Supported by an unrestricted grant from Research to Prevent Blindness.
Keywords: strabismus: treatment