Giant Ocular Surface Squamous Neoplasia Managed with Interferon Alpha-2b as Immunotherapy or Immunoreduction

Objective: To evaluate the efficacy of interferon alpha-2b (IFN alpha 2b) for extensive ocular surface squamous neoplasia (OSSN). Design: Retrospective, interventional case series. Participants: Eighteen eyes in 18 patients. Methods: Each patient with giant OSSN (a single tumor >= 15 mm basal diameter or >= 6 limbal clock-hours) was managed with topical IFN alpha 2b (1 million IU/ml) 4 times daily or with injection IFN alpha 2b (a portion of 10 million IU/ml vial) with follow-up every 1 to 3 months. Main Outcome Measures: Tumor response, recurrence, and treatment complications were evaluated. Results: Eighteen patients with giant OSSN (median diameter [MD], 20 mm; median clock-hours [MCH], 6) were treated with topical IFN alpha 2b (n = 12), injection IFN alpha 2b (n = 3), or both (n = 3). The IFN alpha 2b achieved complete tumor control (immunotherapy) in 13 eyes and partial tumor control with reduction in size (immunoreduction) in 5 eyes. Topical IFN alpha 2b alone (n = 12) provided complete immunotherapy in 7 eyes (MD, 12 mm; MCH, 9) over a median period of 5 months and immunoreduction by 74% in 5 eyes (MD, 20 mm; MCH, 3), allowing for subsequent surgical excision (n = 3), photodynamic therapy (n = 1), or cryotherapy (n = 1) for tumor control. Injection IFN alpha 2b alone (n = 3; median, 1 injection) provided complete control of giant tarsal conjunctival OSSN (MD, 20 mm) over a 1-month period. A combination of topical and injection IFN alpha 2b (n = 3; median, 3 injections) completely resolved larger tumors (MD, 30 mm; MCH, 6) over a 6-month period. Complications of IFN alpha 2b included transient flu-like symptoms (n = 3), corneal epithelial defect (n = 2), and conjunctival hyperemia (n = 1). During a median follow-up of 11 months, there were no tumor recurrences, but 2 new tumors appeared at a remote site from the original tumor, requiring operative intervention. Conclusions: In 72% of giant OSSNs IFN alpha 2b achieved complete control (immunotherapy); there was a reduction in size (immunoreduction) in 28% of giant OSSNs.