A comparison of topical mequitazine and disodium cromoglycate in allergic conjunctivitis induced by a specific conjunctival provocation test

PURPOSE. Twenty-two people with a history of grass pollen allergic conjunctivitis were enrolled outside the pollen season in this study to compare the efficacy of 0.05% mequitazine eyedrops with topical 2% disodium cromoglycate. METHODS. This randomized, double-blind study compared right and left eyes. Subjects received 2% disodium cromoglycate eyedrops in one eye and mequitazine vehicle in the fellow eye 4 times daily for 4 days. For the last instillation, mequitazine vehicle was replaced by one drop of 0.05% mequitazine and 15 min later a conjunctival provocation test(CPT) with grass pollen was performed. RESULTS. The sum of the scores for hyperemia and itching, and total composite score were lower after 0.05% mequitazine than after 2% disodium cromoglycate (p < 0.0001 in each case). The allergen threshold dose which elicited a positive allergic response was higher in the mequitazine group (p < 0.001). Both treatments showed good tolerance upon instillation. No adverse events related to study treatment occurred. CONCLUSIONS. These results demonstrate the superior efficacy of a single drop of 0.05% mequitazine 15 min before CPT compared with 2% disodium cromoglycate 4 times daily for 4 days.