Choroidal vascularity index in thyroid-associated ophthalmopathy.

OBJECTIVE: To investigate the choroidal vascularity index (CVI) in patients with thyroid-associated ophthalmopathy (TAO) and its relationship with clinical features and clinical activity score METHODS: Right eyes of 53 patients with TAO and 53 healthy subjects were scanned for subfoveal choroidal thickness (SFCT), CVI, choroid-stromal area (C-SA), choroid-luminal area (C-LA), choroidal stromal index (CSI), choroid-stromal-to-luminal-area ratio, and CVI and CSI within the central 1500 µm of the macula (CVI1500 and CSI1500 ) by enhanced-depth imaging optical coherence tomography. The results of the TAO group and the healthy controls were compared.

RESULTS: The SFCT was significantly greater in the TAO group than in the control group (p = 0.02). The values of C-LA, C-SA, and total choroidal area (TCA) in the TAO group were significantly higher than those in the control group (p = 0.01, p = 0.04, and p = 0.01, respectively). The increases in SFCT, C-LA, C-SA, and TCA were 12.1%, 12.2%, 16.2%, and 13.6%, respectively. There was no statistically significant difference between the groups for CVI, CSI, CVI1500 , CSI1500 , and choroid-stromal-to-luminal-area ratio (p > 0.05). CVI1500 and CSI1500 have displayed a statistically significant correlation with exophthalmometry and clinical activity score (p < 0.05).

CONCLUSION: The alterations in stromal and vascular structures are proportionally similar in TAO; thus CVI may not be affected significantly. However, CVI1500 and CSI1500 may be associated with disease activity. The choroidal thickening in TAO may be the result not only of vascular mechanisms but also by an increase in stromal contents.