Regression of presumed primary conjunctival and corneal intraepithelial neoplasia with topical interferon alpha-2b.

Purpose. To evaluate topical interferon alpha-2b (IFNα2b) as a lone therapy in the treatment of primary conjunctival and corneal intraepithelial neoplasia (CIN). Methods. Noncomparative, prospective, interventional case series. Seven patients from three institutions, treated between February and October 1999, with presumed primary CIN lesions (clinically diagnosed by corneal specialists) were given topical IFNα2b drops (1 million units/mL) four to six times daily. Follow-up was performed biweekly until there was complete clinical resolution of the presumed CIN lesions. Patients were to continue topical IFNα2b drops for 1 month after clinical resolution. Patient charts and clinical photographs were reviewed, and data were analyzed. Results. All seven eyes had complete resolution of the presumed CIN lesions after an average of 77.0 ± 59.2 days (range, 28–188 days). Average posttreatment follow up was 12.4 ± 2.5 months (range, 9–16 months). No patients were lost to follow-up. No recurrences have yet been seen. Side effects of treatment were limited to mild conjunctival hyperemia and follicular conjunctivitis in four (57.1%) eyes. In all cases, there was total resolution of conjunctival hyperemia and follicular changes within 1 month after cessation of the medication, without additional treatment. Conclusions. Topical IFNα2b alone may be an effective treatment of primary CIN. It appears to be a safe alternative to radiation, intralesional IFNα2b injection, and surgical excision with cryotherapy. Larger population studies with longer follow-up are recommended to better assess the risk of recurrence and other possible adverse effects.