Anterior Segment OCT: High-Resolution Tomography of Corneal and Conjunctival Lesions

Anterior segment high-resolution optical coherence tomography (HR-OCT) plays a pivotal role in the diagnosis of corneal and conjunctival lesions. Ocular surface squamous neoplasia (OSSN), the most common non-pigmented neoplasia of squamous cell origin, has variable appearances which include leukoplakic, papillary, opalescent, and gelatinous presentations. Pigmented lesions entail a lengthy differential, ranging from benign cystic nevi to life-threatening melanomas. The establishment of classic findings of OSSN and other ocular surface lesions on HR-OCT has greatly facilitated the identification of ocular surface pathologies. This chapter serves to outline the characteristic findings attributable to the following ocular surface lesions: ocular surface squamous neoplasia (OSSN), Salzmann’s nodule, pterygium, sebaceous carcinoma, papilloma, lymphoma, amyloid, nevus, melanoma, primary acquired melanosis (PAM), complexion-associated melanosis (CAM), and inclusion cyst. HR-OCT provides morphological views of the lesions that greatly aid in diagnosis, in guiding therapy to full resolution, in detecting early recurrence, and in detecting residual postoperative disease in surgical cases.