Cystic fibrosis(CF) is an inherited disease affecting children, adolescents and young adults with dysfunction of secretory glands.It is caused by mutations in the protein-coding gene which function as the cystic fibrosis transmembrane regulator (CFTR), responsible for the secretion of chloride ions in epithelial cells, adenocytes, sweat gland cells, pancreatic ducts,alimentary and respiratory tracts and eye. Assessment of the relationship between the inflammatory processes and apoptosis in the eye in the course of cystic fibrosis will allow determination of immunological exponents which may facilitate diagnosis.

The aim: To assess the role of chosen parameters of immunological response in the induction of ocular changes in cystic fibrosis patients, particularly chosen chemokine concentrations in the tear fluid and analysis of chosen apoptotic markers expression on conjunctival epithelial cells.

Inclusion Criteria:

• male and female patients aged 3-25 with clinically definite diagnosis of cystic fibrosis
• all patients must give written consent for participation in the study at screening

Exclusion Criteria:

• patients with a history of chronic disease of the immune system
• patients with the history of systemic diseases
• patients with the history chronic ocular diseases
• patients who have been treated with corticosteroids in the past 3 months prior to the screening visit