Hypoglobus, Exophthalmos, and Interpupillary Distance: Measuring Globe Dystopia in Thyroid Eye Disease

Abstract

Purpose: Thyroid eye disease (TED) is characterized by a variety of disfiguring periocular changes. Vertical globe changes affecting the relative position of the eyelids are not well understood in patients with TED. This study seeks to determine the effect of orbital decompression on vertical globe displacement in patients with TED, without TED, and with intraconal tumor (ICT). Methods: For this cross-sectional study, a clinical database was used to identify patients with TED. Comparison groups were drawn from separate anonymized databases. Vertical position and interpupillary distance (IPD) were measured from photographs and exophthalmos was measured via Hertel’s exophthalmometer. Primary outcomes were vertical globe position at baseline and postoperatively in patients with TED and ICT. Secondary outcomes included the relationship between vertical globe position, exophthalmos, and IPD. Results: Among 269 participants meeting the inclusion criteria, mean vertical globe position was significantly lower in patients with TED following lateral decompression surgery compared to controls, after accounting for race, age, and sex. While patients with ICT had a significant difference in preoperative and postoperative IPD, patients with TED did not. Medial or inferior decompression did not significantly change globe position and lateral decompression did not cause lateral canthal dystopia in patients with TED. No association between postoperative changes in exophthalmometry, IPD, and globe position was found in patients with TED. Conclusions: Patients with TED experience hypoglobus that does not improve following decompression surgery. There was no correlation between change in vertical globe position and exophthalmos or IPD among patients with TED. Surgeons should discuss the possibility of hypoglobus as a persistent finding for patients with TED undergoing decompression surgery.