Figure 1

Patterns of the POV defined as “normal” or “abnormal” based on SD-OCT findings. (a) The radial cross-sectional scan of a 27-year-old healthy male participant showed following presentations. Red arrow: the maximum epithelial thickness of the POV was at least 1.5-fold greater than the central corneal epithelial thickness, and progressive tapering of epithelial thickness extending to the corneal and conjunctival sides was seen. Green arrow: sharp stromal tip of the POV pointing to the corneal–limbal junction. Blue arrows: a smooth epithelial–stromal interface. White arrows: limbal stromal vessels with lumen diameters < 50 μm. (b) The tangential cross-sectional scan showed dense, distinct shadows of the POV with regular intervals in the same participant as (a). The central 3-mm width of scanned images (white line) was calculated. In this photo, the calculated density was 8.3 shadow/mm. White arrows indicate the location and shadows of the POV. The right lower figures in (a,b) indicate the scanning area and orientations (gray lines) in radial and tangential cross-sectional scans. (c) Representative figure of the decreased epithelial thickness of the POV in the radial cross-sectional scan. The maximum epithelial thickness of the POV (red arrow) was lower than the peripheral corneal epithelial thickness (Case 2, right superior limbus). (d) The radial cross-sectional scan showed loss of the smooth epithelial–stromal interface of the POV (blue arrows). Dilated limbal stromal vessels were also found (white arrows) (Case 18, left superior limbus). (e) Another figure showing abnormal epithelial thickness of the POV in a radial cross-sectional scan. The epithelium of the POV showed atypical tapering of thickness extending to corneal and conjunctival sides (red arrows). Intraepithelial cysts were also found in this case (Case 15, left nasal limbus). (f) Another representative figure of the uneven epithelial–stromal interface of the POV (blue arrows) showed in a radial cross-sectional scan. Dilated limbal stromal vessels were also found (white arrows) (Case 5, left superior limbus). (g) Loss of the typical sharp stromal tip of the POV (green arrow) was seen with a decreased epithelial thickness of the POV (red arrow) in a radial cross-sectional scan (Case 10, right superior limbus). (h) A tangential cross-sectional scan showed loose shadows of the POV (white arrows) with a calculated density of POV of 2.7 shadow/mm (Case 7, left superior limbus). White arrows indicate the location of POV shadows.