Ultra-High Resolution Optical Coherence Tomography for Differentiation of Ocular Surface Squamous Neoplasia and Pterygia

Objective To assess the use of an ultra–high-resolution (UHR) optical coherence tomography (OCT) as an adjuvant diagnostic tool in distinguishing ocular surface squamous neoplasia (OSSN) and pterygia. Design Prospective case series. Participants Thirty-four eyes of 34 patients with conjunctival lesions clinically suspicious for OSSN or pterygia. Methods All patients were photographed and then imaged with a custom-built UHR OCT device. Subsequently, each patient underwent excisional or incisional biopsy with histopathologic diagnosis. Main Outcome Measures Comparison of preoperative UHR OCT images and the corresponding histopathologic specimen; comparison of epithelial thickness between the 2 groups as measured by UHR OCT. Results Preoperative UHR OCT images of OSSN demonstrated similarities to the histopathologic specimens. Both optical and pathologic specimens showed a thickened layer of epithelium, often with an abrupt transition from normal to neoplastic tissue. Likewise, preoperative UHR OCT images of patients with pterygia were well correlated with the histopathologic specimens. As opposed to OSSN, both UHR OCT and pathologic images of pterygia demonstrated a normal thin epithelium, with underlying thickening of the subepithelial mucosal layers. Differences in the measured epithelial thickness on UHR OCT between OSSN and pterygia were statistically significant, with an average epithelial thickness of 346 μm (standard deviation [SD], 167) in OSSN patients and 101 μm (SD, 22) in pterygium patients ( P