Optical Coherence Tomography (OCT) and Optical Coherence Tomography Angiography (OCTA) for Assessing Thyroid-Associated Ophthalmopathy Activity

To explore the role of retinal and choroidal parameters obtained via optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) in predicting thyroid-associated ophthalmopathy (TAO) activity, providing a scientific basis for improved clinical diagnosis and treatment. This study included 90 active TAO patients (178 eyes), 69 inactive TAO patients (138 eyes), and 66 healthy individuals (132 eyes). It compared choroidal and retinal parameters and magnetic resonance imaging structural differences, analyzed correlations between these parameters, and developed a predictive model for TAO activity. Compared to control and inactive groups, active group had thicker subfoveal choroidal thickness (SFCT) and reduced luminal area, stromal area, and total choroidal area. Active group showed reduced vessel density in the foveal and nasal regions versus inactive group, and in the foveal, superior, and nasal regions versus controls. Foveal avascular zone (FAZ) area was larger in active group than in both control and inactive groups. Active group also had larger inner diameters and signal intensity ratio (SIR) of the extraocular muscles than inactive group. SFCT correlated with proptosis, and FAZ correlated with proptosis, maximum extraocular muscle diameter, and SIR. The multivariate model achieved area under the curve values of 0.836 in overall TAO population and 0.855 in hyperlipidemia subgroup, outperforming the univariate model. Retinal and choroidal parameters, obtained via OCT/OCTA, are keys to developing TAO activity predictive models, with enhanced accuracy in TAO patients with hyperlipidemia.