Corrective Surgery of Severe Esotropia after Decompression in Patients with Graves' Orbitopathy - Comparison of Tendon Elongation and Recession of the Medial Rectus Muscle

Background Patients with Graves' orbitopathy (GO) often show severe esotropia after decompression surgery, especially in cases with severe enlargement of muscles before de-compression. In severely afflicted patients, simple recessions of the medial rectus muscle are not sufficient. In these patients, tendon elongation with bovine pericardium (Tutopatch (R)) is an alternative for simultaneous resection of the lateral rectus muscle. We retrospectively analysed our clinical data of patients who underwent corrective surgery of the medial rectus following three-wall decompression surgery. Methods Patients who underwent classical uni-or bilateral medial recession (MR, BMR; n = 87) or bilateral medial recessions combined with tendon elongation with a graft at one or both muscles (n = 60), were analysed for surgical success (<= 10 (Delta) esotropia, central 20 degrees field of binocular single vision), dose effect (degrees per mm recession/elongation distance) and postoperative ductions. Clinical data directly after surgery and 3 and 12 months later were evaluated in a retrospective manner. Results All patients showed lower dose effects compared to medial recessions without prior decompression: Unilateral recession 1.2 +/- 0.4 degrees/mm, bilateral 1.0 +/- 0.3 degrees/mm, unilateral tendon elongation with contralateral simple recession 0.92 +/- 0.3 degrees/mm and bilateral tendon elongation 0.87 +/- 0.3 degrees/mm. Because of a preoperatively overestimated dose effect, some patients showed undercorrections after surgery. Under consideration of the actual dose effect, surgical success could often be achieved in these severely afflicted GO patients: After simple recessions in 90% and after tendon elongations in 70% of patients. Conclusions In patients following three-wall decompression, higher dosages have to be used for medial recessions and recessions with tendon elongation than with patients without prior decompression. Simple recessions are therefore only to be recommended up to 15 degrees esotropia. In more severe cases up to 25 degrees, tendon elongation can be used.