Abstract
Purpose :
Despite the paucity of supporting data, it has generally been held that proptosis in thyroid eye disease (TED) may provide relative protection from compressive optic neuropathy (CON) by producing spontaneous decompression (Gasser et al., 1986). To investigate further, we studied the relationship between asymmetrical proptosis and asymmetry in CON between orbits in patients with bilateral TED-CON.
Methods :
We retrospectively reviewed the charts of 74 patients (148 orbits) with bilateral TED-CON treated by a single practitioner (M.K.) at the Columbia-Presbyterian Medical Center. Asymmetry of TED-CON was defined as the presence of >25% difference in CP, >2.0 mean deviation difference on HVF, or the presence of an APD. Significant asymmetry of proptosis was defined as >2mm difference in Hertel exophthalmometry (HE) between orbits. Single clinical CON findings and the degree of exophthalmos for all 74 patients was also compared by Pearson correlation. A two-sample t-test was used for APD (Y/N).
Results :
52 of 74 patients with bilateral TED-CON also demonstrated asymmetric CON. Of this group, 37 (71.2%) had symmetric proptosis (avg difference 0.527mm) and 15 (28.8%) had asymmetric proptosis (avg difference 2.93mm). Of those with asymmetric proptosis, 9 of 15 (60%) showed greater proptosis in the eye with worse TED-CON. In the remaining 22 of 74 patients with symmetric CON, 8 (36.4%) had asymmetric proptosis (avg difference 2.88mm). For all 148 orbits, no significant correlation was found between CP and HE (p=0.203, Pearson). This was also not significant for HVF (p=0.489, Pearson) or with APD (p=0.835, two-sample t-test).
Conclusions :
Despite commonly held assumptions, the results of the current study suggest that proptosis is not relatively protective of TED-CON. In total, only 10.8% (8/74) had less severe TED-CON in the eye with worse proptosis. The degree of exophthalmos was not significantly associated with any clinical TED-CON findings, regardless of the relative amount of CON asymmetry, for all orbits. Based on the current findings, the degree of TED related proptosis is unlikely to play a significant role in relieving optic nerve compression.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.