Comparative efficacy and safety of intralesional mitomycin C to intralesional interferon alpha-2b in the management of primary pterygium: A randomised controlled trial

Objectives: Pterygium is a common ocular surface disease with limited non-surgical treatment options. This study evaluates the comparative efficacy and safety of intralesional mitomycin C (MMC) to intralesional interferon (IFN) Alpha-2b as non-surgical treatment options for grades 1 and 2 primary pterygia. Materials and Methods: This double-masked randomised controlled trial was conducted with 100 eyes of consenting adults with grades 1 or 2 primary pterygium attending the eye clinic of Lagos State University Teaching Hospital (LASUTH). Patients with a history of corneal trauma, ulcer, or corneal surgery were excluded from the study. Participants were randomised into two study groups and received either a 0.1 mL injection of 0.2 mg/mL of MMC or 0.1 mL of 3 mIU of IFN alpha-2b, injected into the body of the pterygium, 1 mm away from the limbus. Participants were given prophylactic Ciprofloxacin eye drops topically in the immediate post-injection period. Follow-up evaluations occurred at 1 day, 2 weeks, 6 weeks and 3 months post-injection. Outcomes assessed included pterygium size, vascularity, inflammation, symptom relief and new findings. All data were compared between the two groups and analysed, using IBM Statistical Package for Social Sciences version 25 software for Windows from IBM Corp., Armonk, New York, USA. Results: The study comprised 50 (50%) eyes in each treatment arm. Most participants had improvement in symptoms at 3 months post-injection ( P < 0.001) in both study groups. The median pterygium size before intralesional injection was 1mm in both groups pre-injection; median size remained the same in the IFN alpha-2b group but reduced to 0.5 mm in the MMC group ( P = 0.026). Post-injection, there was a significant reduction in vascularity in the MMC group ( P = 0.041) and a reduction in inflammation in IFN alpha-2b ( P = 0.043) and MMC groups ( P = 0.040). Conclusion: In this study, a single intralesional injection of low-dose MMC was found to be safe and efficacious in reducing the size of primary pterygium. Although IFN alpha-2b improved participants’ symptoms and was safe, it did not result in a reduction in pterygium size in this study. Further research with extended follow-up is recommended.