Efficacy and safety of secondary infero-medial orbital wall decompression after orbital fat decompression in Graves' orbitopathy: A 12-year experience.

PURPOSE: To evaluate the efficacy of secondary bony decompression following primary fat decompression. DESIGN: Retrospective interventional case series. METHODS: Setting: A tertiary university hospital. STUDY POPULATION: A total of 27 eyes from 17 patients who underwent secondary inferomedial orbital wall decompression following primary orbital fat decompression were included. Patients with a history of trauma, extraocular muscle surgery, prior orbital irradiation, or eyelid or orbital inflammation within 6 months prior to decompression were excluded. INTERVENTION PROCEDURE: Secondary inferomedial orbital wall decompression performed for recurrent proptosis or compressive optic neuropathy after primary fat decompression. MAIN OUTCOME MEASURE: Changes in Hertel value, and best corrected visual acuity (BCVA). RESULTS: Primary orbital fat decompression achieved an initial proptosis reduction of 3.4 ± 0.1 mm in 27 eyes. Secondary bony decompression was subsequently performed in 15 eyes from 9 patients with recurrent proptosis and in 12 eyes from 8 patients with dysthyroid optic neuropathy. Secondary bony decompression resulted in a reduction in Hertel measurement by 4.5 ± 2.1 mm, improving from 21.7 ± 2.8 mm to 17.3 ± 1.6 mm ( P < 0.001) at a follow-up period of 40.6 ± 28.7 months. BCVA in patients with dysthyroid optic neuropathy improved from 0.43 ± 0.3 to 0.12 ± 0.15 logMAR ( P = 0.005). Diplopia occurred in 12 of 17 patients (70%), including five with new-onset diplopia. Preoperative diplopia predicted postoperative diplopia in regression analysis. CONCLUSION: Secondary inferomedial orbital wall decompression following primary orbital fat decompression effectively reduces proptosis and improves vision.