(A) Slit-lamp photograph shows OSSN with multiple abnormal blood vessels surrounded the lesion. A white dashed arrow shows the location of the cross-sectional cut. (B) The cross-sectional image reveals mildly thickened epithelium on the cornea and conjunctiva (asterisk) with an abrupt transition from normal to abnormal (arrow). The yellow line shows the bottom boundary of OSSN and sub-epithelial tissue adjacent to the tumor. The red line shows the sub-epithelial tissue (200 μm) underneath the tumor. (C) Cross-sectional OCT detects the blood flow signals in the epithelium of both the corneal and conjunctival OSSN, and the subepithelial tissue under the limbal portion of the OSSN. (D) The tumor thickness map depicts the thickness of the tumor, demonstrating that it was overall uniform in the thickness. (E) Overlay of the enface angiograph with grayscale slit-lamp illustrates the vessels on the ocular surface in relation to the slit-lamp view. (F) The enface angiograph of OSSN and epithelium adjacent to OSSN shows a high density of vessels within both the corneal and limbal portion of the OSSN. (G) The enface angiograph demonstrates dense vessels 200 μm below the tumor, in the sub-epithelial tissue under the OSSN. In the sub-epithelial tissue adjacent to the OSSN, dense vessels were also noted, some of which connected to the vessels under the tumor. (H) The merged image from the angiographic enface images (F and G) shows the vessels within the tumor (red) connect to vessels under the tumor in the sub-epithelial tissue (green).
OSSN, ocular surface squamous neoplasia. Dashed white lines (D, F, G, and H) indicate the tumor boundary. Curve dashed yellow line (D, F, G, and H) indicates the limbus.