Anterior segment optical coherence tomography characteristics of conjunctival papilloma as compared to papilliform ocular surface squamous neoplasia

To describe the anterior segment optical coherence tomography (AS-OCT) appearance of conjunctival papilloma and identify differentiating features from papilliform ocular surface squamous neoplasia (OSSN).A retrospective chart review of individuals clinically diagnosed with conjunctival papilloma (n = 10) or papilliform OSSN (n = 10) based on slit lamp features. Data on demographics, tumour characteristics, and primary treatment were collected. AS-OCT features were assessed including epithelial thickness and reflectivity, a corrugated epithelial surface, presence of an overhanging edge, presence of intrinsic spaces and posterior shadowing. Histopathology was available in 5 papilloma and 3 OSSN specimens.Overall, the majority of individuals in both groups were white males. OSSN lesions were more likely to involve the limbus (80% vs.10%, p = 0.005) and the bulbar conjunctiva (100% vs. 20%, p 0.001) compared to papillomas. On AS-OCT, maximum epithelial thickness was thicker in papilloma compared to OSSN (936 ± 533 vs. 637 ± 207 µm, p = 0.009). The feature that best differentiated papilloma from OSSN was an overhanging edge (100% vs. 0%, p 0.001), where the epithelial lesion was seen on top of underlying normal epithelium. Other features more common in papilloma compared to OSSN included a corrugated epithelial surface (70% vs.10%, p = 0.02), the presence of intrinsic spaces (100% vs. 50%, p = 0.03), and posterior shadowing (100% vs. 40%, p = 0.01).AS-OCT shows differentiating features between papilloma and OSSN with an overhanging edge as a distinctive AS-OCT feature of papilloma.