Choroidal thickness in thyroid eye disease and its correlation with disease activity

Context: This study adds to the existing body of literature on the role of optical coherence tomography (OCT) parameters in active thyroid eye disease (TED) among the Indian population. Purpose: Comparison of choroidal vascularity index (CVI) and subfoveal choroidal thickness (SFCT) in active and inactive TED. Settings and Design: An observational, cross-sectional analytical study conducted at a tertiary eye care hospital in North India that included patients with active and inactive TED. Methods: Demographic details and clinical evaluation were performed for all TED patients. SFCT was determined with OCT by using the Cirrus linear measurement tool. CVI was calculated using Image J software. The SFCT and CVI measurements were compared between both groups. Statistical Analysis Used: Comparison between active and inactive TED groups was done using Mann–Whitney U test for non-parametric data and Student t test for parametric data. Multivariate regression analysis was performed with SFCT and CVI as dependent variables. Results: Sixty-two eyes of 31 patients were included. Thirteen eyes had active TED, and 49 eyes had inactive TED. SFCT was significantly lower in eyes with higher clinical activity score (CAS) and older age. No significant difference was found in CVI between active and inactive TED eyes. Conclusion: SFCT was lower in eyes with higher CAS and older age. Our findings differ from previous studies, which showed a positive correlation between SFCT and CAS. There was no significant difference in CVI between active and inactive TED eyes.