Abstract
Purpose:
Patients with Graves’ orbitopathy (GO) often present large squint angles, especially following decompression surgery of the medial orbital wall. These angles cannot be corrected with conventional recession of the muscle alone. In this pilot study, we report on four patients, where tendon elongation with Tutopatch® was applied, to study the feasibility of this method, in particular the dose- effect relationship.
Methods:
We reviewed the charts of four patients with GO who underwent bilateral recession of the medial rectus muscle and tendon elongation with Tutopatch® within the last 5 years. At the time of surgery, all patients had been stable for at least six months. Squint angles were evaluated at distance and at near fixation preoperatively as well as at postoperative week one, twelve and ≥52 (mean follow-up 49 months).
Results:
Three patients had undergone previous orbital decompression, one of whom had undergone previous bilateral 6mm and 4.5mm, respectively, medial rectus recession with a residual angle of 8°. The mean [range] preoperative angle was 38.8 [8- 68.7]° at distance and 37.5 [6.9- 68.7]° at near fixation. This compared to a mean postoperative angle of 1.1 [0- 2.9]° at distance and 5.1 [-2.0- 8.0]° at near fixation. Per muscle, the mean length of tendon elongation was 6.8 [3.75- 13.5] mm with a mean total recession of 9.8 [3.75- 17.5] mm. The mean dose- effect response was 1.83 [1.0-2.66] °/mm for the distance angle and 2 [1.4- 2.8] °/mm for the near angle. All patients achieved a good functional outcome with orthotropia, however in one patient following additional vertical squint surgery.
Conclusions:
We found the dose-effect response for medial rectus recessions with Tutopatch® in GO to be comparable to reported findings for dose-effect response for the inferior rectus muscle recession with Tutopatch® (2°/mm), albeit with a slightly reduced response at distance. This compares well to an effect of 1.99°/mm for conventional inferior rectus recessions in GO as found in the literature. However, in GO the dose-effect response for conventional bilateral recessions of the medial rectus is considerably less (1.4-1.58°/mm).