Bulbar Conjunctival Microvascular Alterations in Thyroid-Associated Ophthalmopathy Patients with Different Activities

Purpose: To evaluate the morphologic and hemodynamic changes of bulbar conjunctival vessels in thyroid-associated ophthalmopathy (TAO) patients and the correlations with the activity.Methods: Patients diagnosed as TAO with different clinical activity scores (CAS) and healthy participants were recruited. All subjects underwent a complete ophthalmic examination and functional slit-lamp biomicroscope. Vascular variables including the vessel density, vessel complexity, average diameter, blood flow velocity and blood flow rate in microvascular networks were measured. The correlations among microvascular parameters, CAS and exophthalmos were analyzed. Areas under the receiver operating characteristic curves (AUROCs) were applied to evaluate the diagnostic accuracy of microvascular alterations for active TAO.Results: A total of 46 eyes were enrolled in our study. The vessel complexity and blood flow velocity increased in the active TAO group significantly compared with the inactive group and healthy controls (P < .05). Meanwhile, the vessel complexity and blood flow rate were positively correlated with CAS (r = 0.641 and r = 0.526). Bulbar conjunctival microvascular parameters performed a good ability in distinguishing the active stage of TAO (AUROC = 0.793).Conclusions: Increasing bulbar conjunctival vessel complexity and blood flow were evident in TAO with severe inflammation. The measurements of bulbar conjunctival microvasculature could be a reference to evaluate activity in TAO.