Vascular characteristics and haemodynamics of severe and mild pterygium: a quantitative analysis

To investigate vascular characteristics and hemodynamic changes in mild and severe pterygium and explore correlations among clinical parameters.

Cross-sectional observational study.

Sixty-three patients (68 eyes) with pterygium, classified into mild (32 eyes) and severe (36 eyes) groups, and 30 healthy controls (36 eyes) were included. Pterygium length and area were measured via slit-lamp photography. Optical coherence tomography angiography assessed pterygium thickness and vessel density. A functional slit-lamp biomicroscopy measured vessel diameter, vessel length and blood flow velocities. Correlation analysis was performed for each parameter.

The vessel density was significantly higher in the pterygium groups compared to the control group (p < 0.001). Moreover, the vessel density was significantly greater in the severe pterygium group than in the mild pterygium group (p = 0.002). Vessel diameter and length varied significantly (p = 0.01, p = 0.003), with the mild group showing the largest diameter and the severe group the shortest length. No significant differences in hemodynamic parameters were found. Pterygium length and area were positively correlated with age (p < 0.001). The area under the curve (AUC) for pterygium thickness in differentiating mild from severe pterygium was 0.79.

Pterygium demonstrates elevated ocular surface vascular density that correlates with disease severity. Changes in vascular morphology include vessel dilation and increased branching, with dilation most prominent in mild pterygium and branching in severe pterygium. These findings enhance the understanding of pterygium progression and may inform severity-based clinical management.