Choroidal structural changes in inactive thyroid eye disease: a cross-sectional analysis of the choroidal vascularity index.

Abstract

Objective: In this study, we aimed to compare choroidal vascular changes using the Choroidal Vascularity Index (CVI) between patients with inactive Thyroid Eye Disease (iTED) and healthy individuals, and to assess the relationship between CVI and choroidal thickness (CT), smoking history, and clinical parameters.

Methods: In this cross-sectional observational study, the eyes of 30 patients aged 18 to 45 with iTED were compared with the randomly selected eyes of 35 age and gender-matched healthy control individuals. Optical coherence tomography (OCT) scans were taken from all participants. The images were binarized using the ImageJ software, and the total choroidal area (TCA) and luminal area (LA) were measured. The ratio of the LA to the TCA was used to calculate the CVI. The relationships between these measurement parameters and clinical activity score (CAS), exophthalmometry, smoking status, and other clinical parameters were examined.

Results: In the iTED group, CT and CVI values were significantly higher compared to the control group (p < 0.001, p = 0.029). No significant effect of smoking on choroidal parameters was detected in the iTED group. Additionally, there was no statistical correlation between choroidal parameters and either exophthalmometry or CAS (p > 0.05). In the multivariate regression analysis, it was determined that CT showed a significant relationship with thyroid stimulating immunoglobulin (TSI) (p = 0.003).

Conclusions: This study found that CT and CVI were increased in the eyes of patients with iTED compared to healthy controls. The history of smoking did not appear to have any effect on CT and CVI in iTED patients.