Advanced imaging of corneal neovascularisation with a novel swept-source AS-OCTA system

Aims: To explore the clinical application of a novel swept-source anterior segment optical coherence tomography angiography (AS-OCTA) system for imaging corneal neovascularisation (CoNV), assessing limbal vasculature and detecting short-term vascular changes following pharmacologic vasoconstriction. Methods: This cross-sectional observational study included 20 eyes: 10 with clinically diagnosed CoNV of various aetiologies and 10 healthy controls. Each eye underwent AS-OCTA imaging using the BMizar 400kHz Full-Range Swept-Source OCT system at baseline and after administration of 10% phenylephrine (PE). FlowArea (mm2) was automatically calculated across predefined circular regions of interest (ROIs) encompassing the cornea, limbus and episclera. In corneal and limbal ROIs, en face images were segmented into three depth layers: total (epithelium to endothelium), superficial (epithelium to 150 μm) and deep (150 μm to endothelium). Results: CoNV eyes exhibited significantly higher total and deep corneal FlowArea compared with controls (p=0.0002 and p=0.0005, respectively). Post PE, a significant reduction in FlowArea was observed in the total and deep corneal layers of CoNV eyes (p=0.006 and p=0.009, respectively), and in the limbal region of both groups, with significant reductions observed in CoNV and controls (p=0.006 and p=0.003, respectively). Conclusions: This AS-OCTA platform enabled high-resolution, depth-resolved visualization of CoNV and revealed vascular changes following topical vasoconstriction. The extended field of view allowed simultaneous assessment of corneal, limbal and episcleral vasculature within a single scan session, supporting its potential role in both diagnostic evaluation and longitudinal monitoring of anterior segment diseases.