Role of optical coherence tomography angiography in the characterization of vascular network patterns of ocular surface squamous neoplasia.

PURPOSE: To visualize and quantify vascular networks in individuals with ocular surface squamous neoplasia (OSSN) through optical coherence tomography angiography (OCTA). METHOD: Cross-sectional study of OSSN patients. Vascular networks were measured by OCTA in the epithelium and sub-epithelial space in the tumors, adjacent tissue, and in the contralateral eye. Vessel area density (VAD, percent of blood vessels within 2.14 mm(2)), was calculated for each location. Total tumor density (TTD, percent of blood vessels within the entire tumor) was calculated. VAD was assessed separately for corneal and conjunctival locations and compared. RESULTS: Fifteen patients with OSSN were included. The mean age was 61 ± 12 years and the majority were male (80%). The mean tumor area, volume, depth, and TTD were 28.0 ± 9.0 mm(2) (range, 10.9-39.7), 9.1 ± 4.1 mm(3) (range, 3.4-18.8), 334 ± 125 μm (range, 177-571), and 33.2% ± 11.0% (range, 18.7-58.8), respectively. The VAD was highest within the tumor (28.9% ± 8.7%) followed by the adjacent sub-epithelial tissue and the tissue underneath the conjunctival component of tumor. These densities were higher than the VAD in the tissues of the non-involved eye (all P < 0.05). The VAD within conjunctival component of tumor was significantly higher than those with corneal component (29.8% ± 9.5% vs. 21.1% ± 5.5%, p = 0.006). The VAD under conjunctival tumor was also significantly higher than under corneal component (24.1% ± 7.8% vs. 17.0% ± 6.1%, p = 0.024). CONCLUSIONS: OCTA imaging allowed for visualization and quantification of vessel structure and density within, under, and surrounding OSSN.