PURPOSE: To compare the therapeutic effects of two ophthalmic solutions (0.1% olopatadine hydrochloride and 0.5% ketorolac tromethamine) with different pharmacological mechanisms on the clinical signs and Symptoms of seasonal allergic conjunctivitis (SAC). METHODS: Forty patients with the signs and symptoms of SAC (i.e. hyperaemia, itching, mucus discharge, tearing) were included in this placebo-controlled, randomized, parallel group, single centre study. In group 1 (20 patients) one eye of each patient was treated with olopatadine and the other with placebo. In group 2 (20 patients) one eye of each patient was treated with ketorolac solution and the other with placebo. The principal signs and symptoms of SAC (hyperaemia and itching) were evaluated at 30 mins and at 2, 7 and 15 days. RESULTS: In group 1, both parameters improved significantly in eyes treated with olopatadine compared with those receiving placebo at all control examinations (all p 0.05). However, the itching score was significantly lower in the olopatadine group from the second day through to the end of the study (p < 0.05). CONCLUSIONS: Both olopatadine and ketorolac ophthalmic solutions were found to be effective in alleviating the clinical signs and symptoms of SAC compared to placebo. However, olopatadine reduces ocular itching significantly more than ketorolac
