# Ultrasound biomicroscopy and anterior segment OCT in ocular surface squamous neoplasia: complementary roles, case series, and targeted literature review

## TL;DR

This paper explores how two imaging techniques help diagnose and manage eye surface tumors by providing detailed structural information.

## Contribution

The study highlights the complementary roles of AS-OCT and UBM in assessing OSSN depth and proposes a stepwise imaging workflow.

## Key findings

- AS-OCT provides high-resolution imaging of superficial eye structures, aiding in detecting invasive changes.
- UBM visualizes deeper structures like the sclera and ciliary body, identifying clinically occult tumor extension.
- Combining AS-OCT and UBM improves diagnostic accuracy and treatment planning for OSSN.

## Abstract

Ocular surface squamous neoplasia (OSSN) encompasses a spectrum of epithelial malignancies of the conjunctiva and cornea that, untreated, may invade intraocularly or into the orbit. Clinical examination alone may fail to define true depth of invasion, risking under- or overtreatment. Advanced anterior segment imaging provides objective structural information that complements slit-lamp assessment.

This review summarizes the complementary roles of anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) in assessing OSSN depth through a targeted literature review and illustrates their practical applications through representative cases from a single tertiary center.

AS-OCT offers non-contact, high-resolution imaging of the epithelium and stromal interface, facilitating detection of invasive change. UBM, with deeper penetration, visualizes the sclera, ciliary body, angle, and iris, detecting deep or clinically occult extension. The cases demonstrate how each imaging modality contributes to refining diagnosis, guiding treatment selection, and supporting long-term surveillance.

Applying AS-OCT for superficial disease and UBM for suspected deep extension enhances diagnostic confidence and supports personalized, globe-preserving management. Integrating both modalities into a stepwise imaging workflow can improve staging accuracy and align treatment intensity with true disease extent.