Keratoconjunctivitis sicca, also known as dry eye syndrome, is one of the most common ophthalmological diseases and is treated with tear substitutes to moisten the surface of the eye and, in more severe cases of this disease, with local anti-inflammatory therapy with corticosteroids or ciclosporin A. In patients with rheumatological diseases, such as Sjögren's syndrome, dry eye syndrome of severe extent occurs particularly frequently, which is why topical anti-inflammatory therapy is often necessary in these patients.

Aim of this study is to evaluate the treatment of severe dry eye syndrome with topical cyclosporin eyedrops with and without topical corticosteroids at the beginning of the treatment.

Inclusion Criteria:

• Diagnosis of severe keratoconjunctivitis sicca defined by:
• Staining of the cornea ≥ grade III according to the Oxford scale
• OSDI value ≥ 12
• Age between 18 and 90 years
• Primary or secondary Sjogren's syndrome (defined according to the American-European Consensus Group criteria) with a stable course and unchanged treatment for 6 months

Exclusion criteria:

• Pregnancy (excluded with a pregnancy test in patients of childbearing potential)
• Children and young people up to the age of 18
• Eye surgery in the past 6 months
• Simultaneous participation in another study
• Regular use of eye drops, with the exception of tear substitutes
• Use of eye drops containing ciclosporin or glucocorticoids in the last 6 months