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 conjunct ivitis were enrolled outside the pollen season in this study to compare the efficacy of 0.05% mequitazine eyedrops with topical 2% disodium cromoglyca te. METHODS. This randomized, double-blind study compared right and left eyes. Subjects received 2% disodium cromoglycate eyedrops in one eye and mequitaz ine vehicle in the fellow eye 4 times daily for 4 days. For the last instil lation, mequitazine vehicle was replaced by one drop of 0.05% mequitazine a nd 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 composi te score were lower after 0.05% mequitazine than after 2% disodium cromogly cate (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 even ts related to study treatment occurred. CONCLUSIONS. These results demonstrate the superior efficacy of a single dr op of 0.05% mequitazine 15 min before CPT compared with 2% disodium cromogl ycate 4 times daily for 4 days.