Influence of Three Different Formulations of Lachrymal Substitutes on Tear Film Thickness and Other Signs and Symptoms in Patients With Moderate to Severe Dry Eye Syndrome

Dry eye syndrome is a highly prevalent ocular disease with an increasing incidence in the elderly population. Topically administered lubricants are the basis for treatment of this disease. However, exact information about influence on tear film thickness and corneal residence time of topical lubricants is still sparse, therefore no ideal treatment regimen has been found. Recently a new method for assessment of tear film thickness based on ultra-high resolution optical coherence tomography (OCT) has become available. The aim of the present study is to assess the influence on tear film thickness of three different formulations of topical lubricants, in particular Thealoz Duo® Eye Drops, Optive® Eye Drops and Systane Ultra® Eye Drops in patients with moderate to severe dry eye disease. In addition, standard tests for dry eye syndrome, such as the ocular surface disease index (OSDI©), Schirmer I test, corneal fluorescein staining and determination of tear break up time (BUT) will be performed to compare the product effects.