The treatment of recurrent conjunctival and corneal intraepithelial neoplasia with interferon alfa-2b and retinoic acid: ~9 years' follow-up on tumor control.

PURPOSE: To evaluate the long-term follow-up of recurrent conjunctival and corneal intraepithelial neoplasia (CCIN) treated with combination topical interferon alfa-2b and retinoic acid (I/RA). METHODS: Our study represents a retrospective observational interventional series of 82 eyes from 82 patients from a single institution, reviewed for CCIN. All were administered topical interferon alfa-2b 1 million IU/mL QID and retinoic acid 0.01% every other day. Patients had been diagnosed by biopsy. A Kaplan-Meier survival analysis, Wilcoxon signed-rank test and a multivariate logistic regression were statistical tests used to correlate recurrence with patient and tumor variables. RESULTS: 79 eyes assessed for CCIN diagnoses and treated with I/RA achieved tumor resolution. The median tumor-free follow-up was ~109.1 months with a median time to resolution being ~2.8 months. Our median treatment duration was ~11.3 months. The greatest difference in the mean total residual tumor size was identified between Months 0-1 [-7.63 mm2]. The difference in mean total residual tumor size remained significant till 36-months. A statistically significant correlation with recurrence was identified for biopsy type [OR 0.138]. 6 patients experienced papillary conjunctivitis which resolved with dosage reduction. CONCLUSIONS: Combination I/RA was effective in treating CCIN lesions with few transient side effects. The combination of retinoids and interferons may represent a viable topical therapeutic agent with an extended tumor-free follow-up and a large proportion of our study's patients achieving >10 year's tumor-free follow-up. Our treatment duration is long, but by cost-comparing surgical against medical interventions, topical I/RA may serve as a safe and effective alternative.