Study Identifies New OCT-A Biomarker for TED Activity

Patients with active thyroid eye disease exhibit more pronounced changes in the choroid than the retina. Variation in choroidal vessels was found to be a more significant indicator of disease activity than vessel thickness. Photo: Jacob Lang, OD. Click image to enlarge. When assessing patients with thyroid eye disease (TED), clinicians often rely on the clinical activity score. However, experts point out that this tool is subjective and lacks adequate sensitivity, potentially leading to suboptimal outcomes. Given that the retina and choroid are crucial “observation windows” for monitoring ocular diseases, studies have explored the potential of OCT and OCT-A for evaluating TED activity. A paper published recently in Eye examined fundus changes in active and inactive disease to identify reliable indicators of TED activity. The authors found that in active disease, choroidal changes are quite pronounced.The retrospective study included 50 eyes of 30 patients with active TED, 47 eyes of 26 patients with inactive disease and 50 eyes of 26 healthy controls. All patients underwent macular OCT and OCT-A to quantify retinal and choroidal thicknesses, retinal superficial and deep vascular indices, choroidal capillary vascular index and choroidal medium-large vascular index. The researchers used ROC curve analysis to evaluate the performance of each metric for distinguishing active and inactive TED.Their findings showed that subfoveal and parafoveal choroidal thickness was significantly greater in active disease than inactive disease and controls. Of the vascular indices, the choroidal medium-large vascular index in both the subfoveal and parafoveal zones was significantly higher in active disease. The researchers found no significant differences for retinal thickness, retinal vascular indices or the choroidal capillary vascular index between active and inactive groups.ROC analysis showed that choroidal medium-large vascular index at the fovea had superior activity diagnostic efficacy. “The superior performance of CMLVI may stem from its ability to directly reflect the underlying vascular perturbations of active TED, which are more prominently manifested in the choroidal circulation than in retinal changes,” wrote the researchers.They concluded that choroidal medium-large vascular index is the “optimal, objective OCT-A biomarker for assessing TED activity” and added that this “finding holds significant implications for improving the precision of TED activity grading in clinical settings and may contribute to the development of more sensitive and individualized treatment strategies, ultimately optimizing patient management outcomes.”Click here for the journal source. Li Z, Liu J, Tang J, et al. Choroidal medium-large vascular index: a novel OCTA biomarker for assessing activity in thyroid eye disease. Eye 2026. [Epub ahead of print]. This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.