Augmented endoscopic orbital apex decompression in dysthyroid optic neuropathy

To describe a modified technique of endoscopic orbital decompression for dysthyroid optic neuropathy nonresponsive to pulsed corticosteroids.

Retrospective, interventional single centre case series included 17 consecutive patients with dysthyroid optic neuropathy (DON) who were refractory to pulse corticosteroids. Removal of the posteromedial floor and the orbital process of palatine bone (OPPB) was performed in addition to the endoscopic transethmoidal medial orbital wall decompression (ETMOWD), to achieve maximal orbital apex decompression. Main outcome measures were change in visual acuity (VA), color vision, degree of proptosis reduction, incidence of new-onset diplopia, and any complications.

Seventeen eyes (100%) had a statistically significant improvement in VA from 1.0 ± 0.44 LogMAR to 0.0 ± 0.15, with an average improvement of 0.41 ± 0.30 LogMAR (p 0.05, paired t-test). Fourteen out of 16 eyes had a complete improvement in color vision and two eyes had partial recovery. Afferent pupillary defect (76.5%) resolved in all cases. Five out of 10 cases with preoperative visual field defects demonstrated no residual field defects following surgery. The range of proptosis reduction was 0-5 mm (mean 2.7 ± 1.3 mm). No patients with diplopia (12/17) had worsening or developed new-onset diplopia following surgery.

Combined removal of the posterior medial floor including the OPPB with ETMOWD may be a viable alternative in the surgical management of DON.