Ocular surface squamous neoplasia (OSSN). a. Slit-lamp photograph of a 55-year-old white man with a leukoplakic and papillary lesion that extends from the temporal conjunctiva onto the corneal surface and is accompanied by multiple feeder blood vessels. b. High-resolution optical coherence tomography (HR-OCT) demonstrates hyperreflective thickening of the epithelium [asterisk] with an abrupt transition from normal to abnormal epithelium [rectangle], which is characteristic of OSSN. Inset shows scan location.