The choroid as a vascular sensor in pulmonary hypertension: an oculomic mini review.

BACKGROUND

Pulmonary hypertension (PH) is increasingly recognized as a systemic vascular disorder with extrapulmonary end-organ involvement. Within oculomics, ocular imaging biomarkers are explored as systemic disease surrogates reflecting microvascular pathology. Owing to its high flow, fenestrated vasculature, and venous drainage pattern, the choroid is particularly susceptible to venous congestion and impaired ocular perfusion pressure. Optical coherence tomography (OCT) and OCT angiography (OCT-A) enable non-invasive quantitative assessment of choroidal structure, vascularity, and perfusion, thereby giving rise to candidate oculomic readouts.

METHODS

A narrative review of PubMed, Web of Science, and Scopus (through December 2025) identified clinical OCT/OCT-A studies and case reports on choroidal parameters in PH.

RESULTS

Due to concurrent, competing hemodynamic forces, two ends of a dynamic continuum of the choroidal end-organ phenotypes were identified. PH-targeted therapies and autonomic dysregulation may further modify this spectrum. A congestive pachychoroid-like phenotype, demonstrated in idiopathic pulmonary arterial hypertension, is characterized by pressure-dependent choroidal venous congestion, increased subfoveal choroidal thickness, and serous retinal detachment. An ischemic phenotype is characterized by choroidal thinning, perfusion defects, and structural remodeling. In chronic thromboembolic PH, OCT-A shows ischemic signatures with reduced vessel density and an enlarged foveal avascular zone. In precapillary PH, a prospective OCT study reveals reduced choroidal thickness and volume without consistent association with invasive cardiopulmonary hemodynamics.

CONCLUSIONS

Choroidal oculomic candidate markers reflect microvascular remodeling in PH. Currently they lack sufficient validation as standalone surrogates of cardiopulmonary disease severity. Longitudinal multimodal imaging integrated with invasive hemodynamics is required to define their translational clinical utility.