Medications available for the treatment of seasonal allergic conjunctivitis include antihistamines. These medicines block the release of histamine, a substance in the body that is released when an allergic reaction occurs. Novartis (NVS) has developed an eye drop formulation of a well tried antihistamine called ketotifen. This study will compare the efficacy and the tolerability of ketotifen eye drops with emedastine, which is a popular treatment for seasonal allergic conjunctivitis in China.

Inclusion Criteria:

• Age 3 years or older.

• History of seasonal allergic conjunctivitis

• Presence of bilateral ocular itching/conjunctival hyperaemia (redness) at baseline:

  1. at least intensity degree 2 for itching, and
  2. at least intensity degree 4 for composite score of itching and conjunctival hyperaemia

Exclusion Criteria:

Other systemic/ophthalmic conditions

• Presence of any form of allergic conjunctivitis other than seasonal allergic conjunctivitis (e.g. perennial allergic conjunctivitis, vernal keratoconjunctivitis, atopic keratoconjunctivitis, giant papillary conjunctivitis).
• Active bacterial or viral conjunctivitis or history of ocular herpes.
• Presence or history of severe dry eye.

Previous treatments

• Any systemic or ocular corticosteroids within two (2) weeks prior to randomization.
• Any systemic or ocular mast cell stabilizers within two (2) weeks prior to randomization.
• Any other ophthalmic medication within three (3) days prior to randomization.

Other protocol-defined inclusion/exclusion criteria may apply