Muscle tendon elongation with bovine pericardium (Tutopatch®) in patients with Graves' orbitopathy; a prospective, observational, multicentre study.

Purpose: Patients with severe ocular motility restriction and/or large angle strabismus due to Graves' orbitopathy (GO) cannot be adequately addressed with conventional strabismus surgery using large muscle recessions. Muscle tendon elongation surgery, using a spacer of bovine pericardium (Tutopatch®) has emerged as a valuable alternative. The purpose of this study was to assess the long-term outcome of muscle elongation surgery in patients with GO.

Methods: A prospective observational cohort study in three University centres was conducted. All GO patients requiring strabismus surgery with elongation material of one or more rectus muscles were included. One week preoperatively and 3 and 6 months postoperatively, ophthalmic and orthoptic examinations were performed.

Results: Thirty-five patients were enrolled in the study. The mean length of spacer used was 8.2 mm (range 4-13 mm). Tendon elongation was performed on 15 inferior rectus muscles, 33 medial rectus muscles and 9 superior rectus muscles. The field of BSV improved from 0 points [IQR 0-0] preoperatively to 80 points [IQR 6-92] postoperatively (p < 0.001). QoL for functional questions changed from 47 points [IQR 31-63] preoperatively to 78 points [IQR 73-100] postoperatively (p = <0.001). HADS level of anxiety and depression remained below the cut-off score of 15 points (preoperative 11.5 and postoperative 5.7 points).

Conclusions: Using the muscle tendon elongation technique with Tutopatch® in GO patients with severely restricted strabismus, 3 months after surgery a stable large field of BSV can be achieved with associated improvement of the QoL. It is a safe and effective alternative to large muscle recessions for restricted muscle.