Lack of definitive clinical results.

The purpose of this study is to test if olopatadine punctal plugs can reduce the symptoms (itching) of allergic conjunctivitis to ragweed in an Environmental Exposure Chamber model.

Inclusion Criteria:

• History of allergic conjunctivitis to ragweed for at least one year
• Positive skin prick test to ragweed pollen within 12 months prior to visit 1
• BCVA of at leat 20/400

Exclusion Criteria:

• Structural lid abnormalities (ectropion, entropion)
• Active lid disease ( ie moderate or severe blepharitis, meibomianitis) that requires medical treatment
• Presence of follicular conjunctivitis, anterior uveitis or preauricular lymphadenopathy
• History of ophthalmic abnormality, including a history of dry eye
• Perennial allergic rhinoconjunctivitis having significant allergy to animal dander that cannot be avoided during the study period
• History of chronic bacterial or viral ocular infection, such as herpes keratitis, and/or presence of active bacterial or viral ocular infection
• presence of mucous discharge, excess lacrimation or burning as a symptoms of ocular disease
• Currently on any chronic ocular topical medications
• Use of topical or systemic ocular medications during the study period
• History of complications, adverse events, trauma or disease in the nasolacrimal area
• History of symptomatic epiphoria