Corneal melt in conjunctival intraepithelial neoplasia

PURPOSE: Report a case of corneal melt in a patient with conjunctival intraepithelial neoplasia (CIN) treated with topical interferon (IFN) alpha-2B. OBSERVATIONS: An 89-year-old man presented with gelatinous paralimbal lesions of the left eye extending onto the cornea with corneal neovascularization extending 5–6 clock hours. Nasally there was mild absence of the terminal vascular loops of the limbal palisades of Vogt and conjunctivalization. Diffuse punctate epithelial erosions were noted. The corneal graft displayed subepithelial and stromal edema. Anterior segment optical coherence tomography detected hyperreflectivity, sectional thickened epithelium, and abrupt transitions from normal to abnormal tissue. The patient was treated with excision of the corneal and conjunctival lesions with cryotherapy to the conjunctival borders. Excisional biopsy revealed CIN Grade 3 and carcinoma in situ of the cornea. Topical IFN alpha-2B four times daily was initiated postoperatively. Two months later, a central epithelial defect developed. The cornea progressively thinned and corneal melt ensued. The patient had several risk factors for corneal melt including neurotrophic cornea, early limbal stem cell deficiency, history of cryotherapy, keratoconjunctivitis sicca, and chronic use of glaucoma medications and steroid medications. CONCLUSIONS: Interferon alpha-2B is an effective first line treatment for CIN with few side effects. It's side effects include punctate epithelial erosions, conjunctival hyperemia, and follicular conjunctivitis. We report a case of pre-existing keratoconjunctivitis sicca, early limbal stem cell deficiency, neurotrophic cornea, and newly diagnosed CIN Grade 3; it was treated with surgical excision, cryotherapy, and topical IFN alpha-2b with development of corneal melt 2 months later. Caution should be taken when using interferon alpha -2b in patients with pre-existing keratoconjunctivitis sicca, neurotrophic cornea, or limbal stem cell deficiency as it could exacerbate these conditions resulting in corneal melt.