Is Interferon α-2b 1 MillionIU/mL Truly Better Than Tacrolimus 0.03% for Steroid-Resistant VKC ?: Our 2-Year Experience at a Tertiary Health-Care Centre

PURPOSE: To compare the efficacy of eye-drop interferon (IFN) α-2b 1 millionIU/mL with eye-ointment tacrolimus 0.03% in refractory vernal keratoconjunctivitis (VKC). MATERIALS AND METHODS: Fifty patients with VKC refractory to conventional treatment with topical corticosteroids and antihistamines after 4 weeks of regular use were selected retrospectively. Patients were divided into two groups depending on whether they received eye-ointment tacrolimus 0.03% three times a day or eye-drop IFN alpha-2b 1 millionIU/mL three times a day and were followed up for 24 months. The main outcome measures were total subjective symptom score (TSSS) and total objective ocular score (TOSS). RESULTS: Mean baseline TSSS was 7.24±1.98 in Group A (tacrolimus group) and 7.84±1.82 in Group B (IFN group), and it reduced to 1.12±0.83 in Group A and 0.62±0.41 in Group B at 6 months, which was statistically significant compared to the baseline score (p<0.05) as well as between the two groups. Mean baseline TOSS was 6.72±2.07 in Group A and 6.56±2.04 in Group B, and it improved to 1 month onwards to 1.52±0.87 in Group A and 1.0±0.71 in Group B at 6 months, which was statistically significant compared to the baseline score (p<0.05) as well as between the two groups. Side effects like stinging and burning sensations were seen in the tacrolimus group only. CONCLUSION: Our study suggests that while both eye-drop IFN α-2b 1 millionIU/mL and eye-ointment tacrolimus eye ointment 0.03% are both safe and effective steroid-sparing agents in steroid-resistant VKC. IFN α-2b results in greater improvement in subjective symptoms and objective signs, has fewer side effects in long term and is better tolerated as compared to tacrolimus.