Dry eye syndrome (DES) is a highly prevalent ocular condition inducing an inflammatory response of the ocular surface. Common symptoms include ocular discomfort, visual impairment and instability of the tear film with potential damage to the ocular surface.

The rationale of the present study is to compare signs as assessed with new methods such as measurement of tear film thickness, tear film osmolarity and scattering of the tear film with well established methods for assessment of the severity of DES (Break up time, staining of the cornea with fluorescein). Additionally, impression cytology and determination of tear cytokines/chemokines will be performed to obtain information about inflammatory processes on the ocular surface.

Inclusion Criteria:

• Men and women aged over 18 years
• History of dry eye syndrome for at least 3 months
• At least 2 symptoms of dry eye syndrome (foreign body sensation, burning, photophobia, blurred vision, pain, itching) and/or tear break up time < 10 seconds
• Normal ophthalmic findings except dry eye syndrome

Exclusion Criteria:

• Participation in a clinical trial in the 3 weeks preceding the study
• Symptoms of a clinically relevant illness in the 3 weeks before the first study day
• Presence or history of a severe medical condition that will interfere with the study aim as judged by the clinical investigator
• Wearing of contact lenses
• Intake of dietary supplements in the 3 months preceding the study
• Glaucoma
• Treatment with corticosteroids in the 4 weeks preceding the study
• Topical treatment with any ophthalmic drug in the 4 weeks preceding the study except topical lubricants
• Ocular infection or clinically significant inflammation
• Ocular surgery in the 3 months preceding the study
• Sjögren's syndrome
• Stevens-Johnson syndrome
• Pregnancy, planned pregnancy or lactating