Topical Interferon Alfa in the Treatment of Conjunctival Melanoma and Primary Acquired Melanosis Complex

Purpose: To report on topical interferon alfa-2b for conjunctival malignant melanoma (CMM) and primary acquired melanosis with atypia (PAM). Design: Retrospective, interventional case series. Methods: Five eyes of five consecutive patients with biopsy-proven malignant melanoma were treated with topical interferon alfa-2b as treatment for primary or recurrent disease. One drop of interferon alfa-2b (1 million units/ml) was placed into the superior fornix four times daily for three months. Punctal plugs limited systemic absorption. The main outcome measure was tumor regression by clinical examination and comparative slit-lamp photography. Results: Five consecutive patients with conjunctival melanoma (American Joint Committee on Cancer-International Union Against Cancer stages T2 [n = 3] and T3 [n = 2]) were included. Two patients had recurrent corneal tumors, eight and 13 months after local excision, cryotherapy, and topical mitomycin C therapy. Two months after topical interferon alfa-2b treatment, the lesions regressed without side effects. Two additional patients (who could not tolerate topical mitomycin C) were switched to topical interferon alfa-2b. They experienced transient chemical conjunctivitis and have no signs of recurrence (mean, 15 months of follow-up). The fifth had recurrent tumor despite multiple surgeries. This melanoma did not respond to topical interferon alfa-2b nor did the patient tolerate treatment (keratoconjunctivitis). No systemic side effects were noted. Conclusions: We present evidence that conjunctival and corneal melanoma regresses after exposure to topical interferon alfa-2b. A larger-scale longer-term study must evaluate the long-term efficacy and safety of this therapy.