The COPD-driven "lung-eye axis": mechanisms and clinical evidence of ocular disease.

COPD is a chronic systemic disease marked by ongoing airflow obstruction, sustained inflammation, and increased oxidative stress, whose pathological impact extends far beyond the lungs. Growing data suggest that COPD impacts the eye via chronic systemic inflammation, intermittent or persistent hypoxia, oxidative stress, and endothelial dysfunction, establishing a cross-system pathological connection termed the "lung-eye axis." Evidence from clinical and experimental studies indicates potential associations between COPD and key ophthalmic conditions, such as dry eye disease, cataract, glaucoma, diabetic retinopathy, and age-related macular degeneration. The underlying mechanisms largely involve the retina and optic nerve, which rely heavily on oxygenation and microvascular homeostasis, highlighting them as prime ocular targets of COPD systemic effects. The application of noninvasive imaging, such as OCT and OCTA, offers quantitative and objective preliminary evidence for the lung-eye axis, indicating that ocular imaging could function as a surrogate marker of systemic disease burden in COPD. Despite being largely cross-sectional and methodologically constrained, the proposed "COPD-driven lung-eye axis" framework offers a cross-organ perspective for understanding the systemic characteristics of COPD. There is an urgent need for large, prospective, multicenter studies combining pulmonary function tests, blood gas measurements, inflammatory biomarker profiling, and multimodal ocular imaging to establish causal links and clinical utility, providing novel strategies for precision stratification and early intervention of COPD-related systemic complications.