Abstract
Purpose: :
To assess the use of an ultra-high resolution optical coherence tomography (UHR-OCT) as an adjuvant diagnostic tool in distinguishing ocular surface squamous neoplasia (OSSN) and pterygia.
Methods: :
Thirty-four eyes of 34 patients with conjunctival lesions clinically suspicious for OSSN or pterygia were photographed and then imaged with a custom built UHR-OCT. Subsequently, each patient underwent excisional or incisional biopsy with histopathological diagnosis. An analysis of pre-operative UHR-OCT images and the corresponding histopathologic specimens was performed, and UHR-OCT measured epithelial thickness was evaluated in the two groups.
Results: :
Pre-operative UHR-OCT images of OSSN demonstrated striking similarities to the histopathologic specimens. Both optical and pathological specimens showed a thickened layer of epithelium, often with an abrupt transition from normal to neoplastic tissue. Likewise, pre-operative UHR-OCT images of patients with pterygia were well correlated with the histopathologic specimens. As opposed to OSSN, both UHR-OCT images and pathologic slides 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 (ROC) 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: :
UHR-OCT may be a promising non-invasive diagnostic tool to evaluate ocular surface lesions. In addition to a statistically significant difference in epithelial thickness, a high degree of morphologic correlation with the histopathology results demonstrates its potential use in evaluating ocular surface squamous neoplasia and pterygia.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • tumors • cornea: epithelium