Research progress of optical coherence tomography and optical coherence tomography angiography in thyroid-associated ophthalmopathy

Thyroid-associated ophthalmopathy(TAO)is the most common orbital disease in adults, characterized by inflammatory cell infiltration in the retrobulbar and periorbital soft tissues. This condition induces a series of pathological alterations including enlargement of the extraocular muscles, increased retrobulbar adipose tissue, soft tissue edema, and orbital fibrosis, resulting in elevated intraorbital pressure and impeded venous return, and in severe cases, can cause dysthyroid optic neuropathy(DON), which is one of the main causes of vision loss in patients. There are abnormalities in ocular hemodynamics in TAO patients, and the occurrence of DON is closely related to optic nerve ischemia. Therefore, it may be important to understand and monitor changes in ocular blood flow in TAO patients as early as possible. Optical coherence tomography(OCT)and optical coherence tomography angiography(OCTA)can obtain in vivo images of retinal and choroidal tissue structure and vasculature with non-contact, non-invasive, rapid, and high-resolution characteristics. They have been used to study changes in ocular blood flow in a variety of ophthalmic and systemic diseases. To date, a multitude of scholars have employed OCT and OCTA to investigate the microcirculatory structure and blood flow in the fundus of patients with TAO. However, the research results are still controversial due to differences in measurement techniques, confounding factors, and study populations, and there is no relevant domestic literature review in this field. This article reviews the research progress of OCT and OCTA in TAO, thus exploring the application value of OCT and OCTA technology in TAO.