Objective: To assess the use of an ultrahigh-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<0.001). By receiver operating characteristic curve, the sensitivity and specificity of UHR OCT for differentiating between OSSN and pterygia was found to be 94% and 100%, respectively, using a cutoff value of 142 μm. Conclusions: Ultrahigh-resolution OCT may show promise as a noninvasive diagnostic tool to evaluate ocular surface lesions. In addition to a statistically significant difference in epithelial thickness, a significant degree of morphologic correlation with the histopathologic results demonstrates its potential in evaluating ocular surface squamous neoplasia and pterygia. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
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