Bilateral inferior rectus muscle recession in patients with graves orbitopathy: is it effective?

Purpose: To evaluate the effect of bilateral inferior rectus recession regarding improvement of elevation, reduction of abnormal head tilt and vertical squint angle in patients with Graves orbitopathy.

Method: Retrospective case series. Patients with Graves orbitopathy who underwent symmetric or asymmetric bilateral inferior rectus recession were selected for this study. Effect on change of elevation, depression cyclodeviation, and vertical squint angle was calculated 3 months and 6 to 12 months postoperatively.

Results: Forty-three patients could be included, who underwent a recession of both inferior recti by 1 of the 5 surgeons. Three months postoperatively, the elevation changed from 12° ± 6.9° preoperatively to 19° ± 6.7° postoperatively (p = 0.000) and the depression from 54° ± 6.2° preoperatively to 48° ± 9.2° postoperatively (p = 0.005). Total duction range remained stable (p = 0.728). Three months after surgery, motility did not change significantly anymore. The dose effect response on elevation was 1.7° ± 1.7°/mm, and was higher in case of severe preoperative elevation restriction (r = -0.405). Three months postoperatively, the excyclodeviation changed from 6.4° ± 6.0° to 0.4° ± 6.0° in primary position (p = 0.000). However, in downgaze 4 patients developed a significant incyclodeviation of > 5°. Muscle volume, prior decompression surgery, or performing surgeon did not influence the outcome.

Conclusion: Bilateral recession of the inferior rectus muscles in patients with Graves orbitopathy results in a shift of vertical duction range toward upgaze and a significant decrease of excyclodeviation. Overcorrection of cyclodeviation in downgaze has to be considered before planning this type of surgery. Poor preoperative elevation contributes to higher dose-effect responses. Considering all variables, the orthoptic picture does not change after 3 months of surgery.