Diagnostic value of ocular imaging biomarkers in chronic obstructive pulmonary disease: a multicenter prospective cross-sectional study.

Background: Chronic obstructive pulmonary disease (COPD) is a common heterogeneous respiratory disease with systemic involvement. Although pulmonary function testing remains essential for diagnosis, its use in primary care is limited. Optical coherence tomography angiography (OCTA), a noninvasive technique for assessing ocular microcirculation, may provide new biomarkers for the auxiliary diagnosis and early identification of COPD. This study aimed to evaluate the diagnostic value of OCTA-derived ocular imaging biomarkers in COPD. Methods: In this cross-sectional study, 150 patients with COPD and 150 healthy volunteers were recruited between May 2024 and May 2025. According to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2023 criteria, COPD patients were categorized into a mild-to-moderate group (Group 1, n=101) and a severe-to-very severe group (Group 2, n=49), while healthy participants served as controls (Group 3, n=150). A total of 38 OCTA parameters were assessed and compared across groups. Multivariate logistic regression was used to construct predictive models, and model performance was evaluated using receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). Results: Compared with healthy controls, COPD patients exhibited thinning of the retinal nerve fiber layer (RNFL), reduced vascular density in the deep capillary plexus (DCP) and radial peripapillary capillaries (RPC), as well as enlargement of the foveal avascular zone (FAZ) in both area and perimeter (P<0.01). The overall diagnostic model demonstrated excellent discrimination between COPD patients and healthy controls, with an area under the ROC curve (AUC) of 0.906, sensitivity of 87.5%, and specificity of 81.5%. The early identification model also showed good performance in distinguishing mild-to-moderate COPD from healthy subjects (AUC 0.812, sensitivity 83.7%, specificity 66.4%). Conclusions: OCTA provides a novel, noninvasive approach for evaluating COPD and may complement pulmonary function testing, particularly in primary care settings. As a simple and scalable imaging tool, OCTA may have potential value in the auxiliary diagnosis and early screening of COPD. Further validation in larger, multiethnic cohorts and integration with multimodal biomarkers are warranted to enhance its generalizability and translational potential.