ABSTRACT
INTRODUCTION The vast majority of corneal ulcers occur when additional systemic or local factors disrupt the corneal defense mechanisms. Local factors include conditions that alter the lids (such as entropion, ectropion, and seventh nerve palsy), disorders of lacrimation (such as dry eye, dacryocystitis), conjunctival disorders (such as pemphigoid, vernalconjunctivitis, Stevens-Johnson), corneal diseases (such as neurotrophic disease, bullous keratopathy, herpetic ulceration), and systemic factors such as alcoholism, coma, diabetes, nutritional or immune defi ciency.
