Endoscopical Orbital Fat Decompression with Medial Orbital Wall Decompression for Dysthyroid Optic Neuropathy.

Objective: To describe a novel approach to orbital decompression for dysthyroid optic neuropathy (DON). Methods: An augmented endoscopic transethmoid medial orbital wall decompression (ETMOWD) was performed on 43 consecutive patients (72 eyes) with DON in order to access the orbital apex adequately. Concurrently, endoscopic transethmoid fat decompression (ETFD) using a novel aspiration/cutting instrument to remove orbital fat was performed for further reduction of proptosis. All patients were followed up periodically for at least 6 months. Outcomes such as improvement of visual acuity (VA), color vision, degree of proptosis reduction as well as the incidence of surgical induced diplopia were analyzed at the final review. Results: Sixty-nine out of 72 eyes (95.8%) had a statistically significant improvement in VA from -0.65 +/- 0.30 to -0.25 +/- 0.22 postoperatively, with a mean improvement of 0.55 +/- 0.17 (p < 0.001). Thirty-four out of 45 eyes had an improvement in color vision (p < 0.001). The range of proptosis reduction was 4 to 9 mm (mean 6.2 +/- 1.2 mm). Postoperative symmetry was achieved to within 2 mm using an exophthalmometer in 39 of 43 patients (90.7%). Five patients developed diplopia in the postoperative phase, but had complete resolution within 3 months. Two patients had further deterioration in their diplopia following surgery. Conclusion: Our technique of a combined ETFD with ETMOWD appears to be effective in managing patients with DON, with minimal morbidities and a low incidence of postoperative diplopia.