Impact of the ethmoid volume on endoscopic medial wall decompression outcomes in Graves' orbitopathy

Endoscopic orbital decompression is a well-established technique for Graves orbitopathy treatment.

Measurement of the ethmoid volume and its correlation with proptosis reduction in patients undergoing endoscopic orbital decompression for Graves' orbitopathy.

We retrospectively reviewed clinical charts of 209 patients (319 orbits) operated by a surgeon at our institution between 1998 and 2019.

Average age was 46.9 years. About 83.3% of the patients were female, 54.6% were smokers, 93.8% were euthyroid at the time of decompression, 3.8% were hypothyroid and 2.4% were hyperthyroid. About 77.5% of the patients underwent bilateral surgery, the remainder and unilateral. Subsequent stages included strabismus surgery in 22.5% patients, Müllerectomy 37.8%, with or without canthoplasty (14.8 vs. 23%). Mean proptosis reduction was 4.61 mm. Mean ethmoid volume was 5.57 mm³. Ethmoid volume had a moderate positive correlation with proptosis reduction (r _s = 0.49, p < .001). Further investigation, statistically significant moderate correlation was found only in the small (SE) and big (BE) ethmoid groups.

We advise evaluating ethmoid sinus pneumatization on computed tomography before decompression to estimate possible anatomical limitations. Additional wall decompression might be advocated in most severe cases.