Optical coherence tomography angiography measurements in thyroid eye disease: A systematic review and meta-analysis

Thyroid eye disease (TED) is defined as a common ocular manifestation of graves' disease, which affects the dynamics of the retinal vessels by various autoimmune and mechanical ways. Herein, we evaluate the retinal microvascular alterations in TED subjects using optical coherence tomography angiography (OCTA). PubMed, Scopus and Web of Sciences were systematically searched for relevant studies assessing OCTA measurements in TED patients and healthy controls. Meta-analysis was conducted on OCTA parameters with at least two studies using the same OCTA device. Fifteen related studies assessed the total of 771 TED eyes (13 studies evaluating inactive TED and 10 with active TED). Patients with active TED exhibited significantly reduced vessel density (VD) in both the superficial and deep capillary plexuses compared to inactive TED and healthy controls, particularly in whole image analyses and parafoveal region. Additionally, the foveal avascular zone was significantly enlarged in active TED relative to inactive TED and HCs. Radial peripapillary capillary VD was reduced in active TED compared to the inactive stage. These highlights the potential of OCTA as a valuable noninvasive tool for TED's diagnosis assistance and disease progression monitoring. Future research should aim to assess retinal VDs in larger and more diverse samples, considering disease activity, to achieve more conclusive results.