Elongation of the inferior rectus tendon with fascia lata graft for large vertical squint angles in patients with Graves’ orbitopathy

PURPOSE: To investigate the use of fascia lata (FL) grafts for inferior rectus muscle (IRM) tendon elongation in patients with large vertical squint angles with Graves’ orbitopathy (GO). METHODS: In this retrospective study, we included a consecutive series of 20 eyes of 13 patients with GO who underwent IRM tendon elongation with FL. Orthoptic and ophthalmologic examinations including measurement of the head posture, the extent of deviation in primary position (PP), elevation, motility, and binocular diplopia at the tangent of Harms were conducted preoperatively and after a mean postoperative time of 10.8 (5.0–35.0) months in all patients. RESULTS: The mean total repositioning distance was 9.3 ± 3.6 (3.5–16.0) mm. Postoperatively, we found a significant increase in elevation (5.4 ± 2.4 vs. 2.7 ± 2.4 mm preoperatively, p = 0.011). A significant reduction in vertical squint angle (2.8 ± 3.7 vs. 20.2 ± 18.8 Δ preoperatively, p = 0.004), chin elevation (2.3 ± 3.7 vs. 12.9 ± 6.3° preoperatively, p < 0.001), extorsion in PP (0.1 ± 3.8 vs. 8.4 ± 7.8° preoperatively, p = 0.002), and in elevation (1.8 ± 4.8 vs. 11.1 ± 10.9° preoperatively, p = 0.004) occurred postoperatively. A mean dose–effect relation of 2.6 ± 2.9 Δ/mm was calculated. Postoperatively, the lower eyelid retraction was significantly increased (1.5 ± 1.4 vs. 0.4 ± 0.5 mm preoperatively, p = 0.005). CONCLUSION: IRM tendon elongation with FL is a feasible and effective procedure without relevant risk for surgery-related complications.