Seasonal allergic conjunctivitis (SAC) is an irritating eye condition that affects many people, caused by hypersensitivity to normally harmless substances such as pollen, and often accompanies seasonal hay fever. Treatments that can be used before initiating medical therapy include artificial tear supplements (ATS) and cold compresses (CC). However, there is no evidence in the scientific literature that demonstrates their efficacy compared to no treatment or their combined effect with anti-allergic medication. Therefore the investigators aim to examine the efficacy of ATS and CC alone, in comparison to anti-allergic medication, and CC in combination with anti-allergic medication. In addition, the investigators also aim to determine the time course of ocular allergic reactions. At the end of the study the investigators will be able to see whether or not ATS and CC are effective in treating SAC.

There will be a total of 6 study visits, each lasting approximately 1 hour and separated by at least 2 days. At the beginning of each visit, a set of measurements will be taken by an experienced optometrist. These are:

• What symptoms you are feeling and how severe they are - you will be asked to complete a short questionnaire about how your eyes currently feel.
• The redness and temperature of your eyes - the front surface of both eyes will be photographed using digital cameras.

After these measurements we will ask you to stand inside a specially designed room where the environment can be controlled by a computer. The pollen that you were found to be allergic to will then be introduced into the atmosphere of the room, so that the signs and symptoms of SAC can be induced - this is intentional, but normally resolves within a few hours with no treatment. At each visit, you will experience a different duration (no longer than 10 minutes) and either no treatment, artificial tear supplement (ATS; preservative free ocular lubricant), cold compress (CC; cooled gel eye mask) or anti-allergic medication (epinastine hydrochloride 500μg/mL). The measurements will then be repeated even 5 minutes for an hour.

After the final set of measurements, the front surface of your eyes will be assessed using a temporary dye to highlight using a blue light any changes. Fluorescein dye does not sting, lasts only a few minutes and has no effect on vision or driving. However it may cause a self limiting mild allergic reaction where the eyes become red, irritated and sore but this is highly unlikely as there are no known reported cases. In the unlikely event this does happen the experienced optometrist is immediately available to manage the condition.

The anti-allergic drug epinastine hydrochloride (Elestat, Allergan) is a prescription only medicine indicated for the treatment of allergic conjunctivitis. As with all medications, there are potential side effects - although uncommon (1 in 10 to 1 in 100 people), there may be a slight burning sensation on application but this temporary and subsides quickly. The epinastine formulation also contains preservatives called benzalkonium chloride and disodium edetate. As with fluorescein sodium, these may cause a self limiting mild allergic reaction. In the unlikely event this does happen the experienced optometrist is immediately available to manage the condition.

Study Length and Reimbursement Each of the 6 measurement visits is separated by 7 days therefore the total study length for each participant is 6 weeks.

Inclusion Criteria:

• history of seasonal allergic conjunctivitis or seasonal allergic rhinoconjunctivitis (seasonal hay fever) that is not currently active.

Exclusion Criteria:

• eye surgery in the last 3 months
• active eye condition
• adverse reaction to ocular drugs or dyes
• history of anaphylaxis (severe systemic allergic reaction)
• use any ocular medication or systemic medications (antihistamines, mast cell stabilisers, non-steroidal anti-inflammatory drugs or steroids) at least 14 days prior to the start and for the duration of the study

Subjects underwent skin prick and bilateral conjunctival challenge tests to confirm systemic and ocular allergic sensitivity to grass pollen