Abstract
OBJECTIVE: To assess the value of optical coherence tomography (OCT) and OCT angiography (OCTA) for the early diagnosis of dysthyroid optic neuropathy (DON) in patients with thyroid-associated orbitopathy (TAO). METHODS: This retrospective study (2022-2024) included 52 TAO eyes (22 DON, 30 non-DON) and 52 healthy controls. OCT/OCTA scans evaluated structural features (ganglion cell complex, peripapillary retinal nerve fiber layer, Bruch's membrane opening-minimum rim width [BMO-MRW]) and vascular features (superficial retinal capillary plexus [SRCP] density, choroidal capillary vascular density, foveal avascular zone [FAZ] area). Contrast sensitivity function (CSF), thyroid peroxidase antibody (TPOAb) status, and glutamate levels were also analyzed. Multivariate logistic regression identified risk factors, and receiver operating characteristic curves evaluated diagnostic performance. RESULTS: Most structural OCT features showed no significant differences, except CSF, which was significantly reduced in DON eyes (P < 0.001). Vascular features such as SRCP density and choroidal capillary density decreased progressively in DON, while FAZ area was significantly larger (all P < 0.001). TPOAb positivity and glutamate levels were highest in the DON group (P < 0.001). Multivariate analysis identified SRCP density, FAZ area, TPOAb positivity, and glutamate concentration as independent risk factors for DON. A combined model of BMO-MRW and subfoveal choroidal thickness achieved the highest diagnostic accuracy (AUC = 0.940, sensitivity = 88.0%, specificity = 90.0%). CONCLUSIONS: Multimodal imaging combining OCT and OCTA features improves the sensitivity and specificity of early DON diagnosis, offering a reliable, noninvasive screening approach for clinical practice.