## 3 Experiments and Results
### Keratitis Patient  
Figure 4 shows the experimental results acquired by our multi-modal anterior imager on the keratitis patient. An inflamed lesion can be clearly observed on the appearance image (Figure 4a). As shown in the UHR-OCT image (Figure 4b,c), the inflamed corneal lesion presents as highly reflective structures in the central region close to the apex of the cornea; the defects of the cornea are clearly visible with violation of the epithelium and Bowman's layer until the anterior stroma. Figure 4d-f shows the single-shot image of the conjunctival vessel network of the keratitis patient and the segmented and skeletonized vessel network processed with our customized software. The fractal dimensions of the microvascular network of the keratitis patient were calculated to be: mono-fractal D\({}_{\text{box}}\) = 1.59 and multi-fractal D\({}_{0}\) = 1.76. Figure 4g,h is a still conjunctival vessel image captured from one representative conjunctival blood flow video clip of the keratitis patient (Video s2), and the zoom-in area shows resolved clusters of red blood cells. Processed by the software, the calculated quantitative hemodynamic results of the keratitis patient are: mean vessel diameter D = 23.12 \(\pm\) 1.00 \(\mu\)m, cross-sectional area = 419.68 \(\pm\) 37.00\(\mu\)m\({}^{2}\), axial blood flow velocity V\({}_{\text{a}}\) = 0.27 \(\pm\) 0.06 mm/s, cross-sectional blood flow velocity V\({}_{\text{s}}\) = 0.18 \(\pm\) 0.06 mm/s and blood flow rate Q = 119.3 \(\pm\) 42.17 pl/s. Figure 4i is the fluorescein stain image of the keratitis patient highlighting the inflamed lesion location, size and boundary on the ocular surface.  
Table 1 shows the comparison of the obtained quantitative morphological and hemodynamic parameters from the healthy subject and keratitis patient. In general, the conjunctival vessel  
Figure 4: Experimental results on the keratitis patient with the multi-modal anterior eye imager. (**a**) Appearance image of the keratitis patient’s eye; the blue dashed line indicates the UHR-OCT scanning position. (**b**) UHR-OCT image of the inflamed cornea and (**c**) the zoom-in area showing the highly reflective, inflamed lesion. (**d**) The bulbar conjunctival vessel network image of the keratitis patient; the yellow box indicates the location where the representative video clip (Video s2) was taken. (**e**) The segmented vessel network image and (**f**) the skeletonized vessel network image of the selected region (green box) in (**e**). (**g**) A representative conjunctival vessel image captured from the bulbar conjunctival blood flow video clip (Video s2). (**h**) Zoom-in area of (**g**) showing resolved clusters of red blood cells (red arrows). (**i**) Fluorescein stain image of the keratitis patient.  
hemodynamics and fractal dimension values were in agreement with previous studies [31; 32; 33; 34; 35], which validates the performance of our system. The mono-fractal D\({}_{\text{box}}\) and multi-fractal D\({}_{0}\) of the keratitis patient are both higher than the healthy subject, indicating an increase of both vessel density and complexity. Although the blood flow velocity shows no obvious difference between the keratitis and healthy subject, the mean vessel diameter of the keratitis patient is much larger compared with that of the healthy subject, resulting in a higher flow rate of the bulbar conjunctival vessels in the keratitis patient [5; 6].