Choroidal vascularity index in thyroid-associated ophthalmopathy

Area of Science:

• Ophthalmology
• Endocrinology
• Medical Imaging

Background:

• Thyroid-associated ophthalmopathy (TAO) is an autoimmune condition affecting the eye.
• Choroidal vascularity index (CVI) is a measure of vascularity in the choroid, a layer of the eye.
• Understanding choroidal changes in TAO is crucial for disease management.

Purpose of the Study:

• To investigate the choroidal vascularity index (CVI) in patients with TAO.
• To explore the relationship between CVI and clinical features, including disease activity.
• To compare choroidal parameters between TAO patients and healthy controls.

Main Methods:

• Enhanced-depth imaging optical coherence tomography (EDI-OCT) was used to scan the eyes of 53 TAO patients and 53 healthy controls.
• Measurements included subfoveal choroidal thickness (SFCT), CVI, choroid-stromal area (C-SA), choroid-luminal area (C-LA), choroidal stromal index (CSI), and their 1500 µm macular equivalents (CVI1500, CSI1500).

Main Results:

• TAO patients showed significantly greater SFCT, C-LA, C-SA, and total choroidal area compared to controls.
• No significant differences were found in CVI, CSI, CVI1500, or CSI1500 between the groups.
• CVI1500 and CSI1500 demonstrated a significant correlation with exophthalmometry and clinical activity score.

Conclusions:

• While overall CVI may not be significantly altered in TAO due to proportional changes in stromal and vascular components, macular CVI (CVI1500) and CSI (CSI1500) may indicate disease activity.
• Choroidal thickening in TAO likely results from both vascular and stromal changes.