Evolution of asymmetric proptosis during the active phase of thyroid eye disease.

Asymmetric proptosis is common in the setting of early active TED and decreases by 50% when the stable phase is reached. Therefore, diagnostic imaging is not routinely required to exclude alternative pathology in the cases of asymmetric TED. Perhaps more importantly, this finding supports the surgical paradigm of stable phase, graded orbital decompression, performed when the ultimate globe positions are achieved to avoid late postoperative asymmetry, resulting from the unanticipated evolution of proptosis when surgery is performed during the active phase of TED.