Ocular surface squamous neoplasia with orbital tumour extension: risk factors and outcomes.

Orbital extension of OSSN is rare. Outdoor occupation, HIV infection, larger and thicker tumours in the inferior quadrant with forniceal and/or tarsal conjunctival involvement with nodular or noduloulcerative morphology, poor tumour differentiation, SCC, spindle cell and mucoepidermoid variants on histopathology are at increased risk for orbital tumour extension.