Background: Vernal keratoconjunctivitis is a chronic, seasonally exacerbated, allergic inflammation of the eye. The study aims to evaluate the efficacy and safety of oral montelukast in treating vernal keratoconjunctivitis in pediatric patients.

Methods: This is a 26-week, prospective, randomized, open-label study. Fifty-eight patients were randomly assigned to two groups-the treatment (montelukast) and control groups. At the beginning of the study, both the groups received topical loteprednol etabonate (0.1%) in tapering doses for a month, and topical olopatadine (0.1%) for the first 3 months. Symptoms and signs observed before and after treatment and assigned scores were studied. The primary efficacy endpoint was change in the mean score on the visual analog scale (VAS) for each subjective symptom. The secondary efficacy endpoint was change in the total score of objective signs.

Results: The montelukast group showed clinically relevant improvements in the signs and symptoms of vernal keratoconjunctivitis, compared to the control group. There was considerable improvement in clinical signs. Individual symptoms such as redness, itching, foreign body sensation, and tearing showed significant improvement at 6 months follow-up. The gradual improvement in symptoms until the last visit was statistically more significant within montelukast group. Mean VAS score showed statistically significant improvement in itching (p < 0.001) and redness (p < 0.008) in montelukast group even at 3 months. No adverse events were reported in either group.

Conclusions: Montelukast was found to be safe and effective as a long-term therapy to prevent relapse in moderate to severe vernal keratoconjunctivitis.