Long term study of topical interferon α-2b eye drops as primary treatment of ocular surface squamous neoplasia

To assess the efficacy of topical interferon α-2β(IFN) eye drops as a primary treatment for ocular surface squamous neoplasia(OSSN) and evaluate factors that impact response to treatment and recurrence of OSSN.

A retrospective study of 143 OSSN patients treated with topical IFN(1MIU/ml) from January 1998 to June 2021. The diagnosis was based on clinical examination and anterior segment optical coherence tomography, with histologic confirmation was present in 46.2% of patients. Data on demographic, tumor characteristics, treatment outcome, and side effects were collected. The primary outcomes were tumor resolution frequency and recurrence rate. Secondary outcomes were predictive factors for resolution and recurrence and side effects of treatment.

Participants were mostly older (mean age, 69 years, SD 12.9, range 29-97), white(89%) males (74%). Complete tumor resolution was achieved in 80.4% of individuals with a mean time to resolution of 4.2 months (SD 2, range 0.5-12.3 months). On multivariable analysis, history of skin cancer (HR: 0.66, p = 0.05, 95%CI: 0.44-0.99) and immune system abnormalities (HR: 0.37, p = 0.009, 95%CI: 0.18-0.79) reduced the risk of tumor resolution, while a prior history of OSSN (HR: 3.49, p < 0.001, 95%CI: 1.76-6.93) increased the risk of resolution. With a mean follow-up time of 44.3 months (SD 50.9, 0-290 months), the recurrence rate was 0%, 2.3% and 3.1% at 1, 2, and 5 years respectively. Mild hyperemia(18.9%) and pain(10.6%) were the two most common side effects.

Topical IFN eye drops are a safe and effective primary treatment modality for OSSN with a reasonable side effect profile.