[Corneal contact time of artificial tear solutions].

In 30 subjects without ophthalmological disease the corneal contact time of a new artificial polyacrylic-based tear gel (Vidisic, produced by Dr. Mann, Berlin) was compared with a well-known artificial polyvinyl alcohol-based tear solution. The Vidisic concentration remained in the corneal tear film 7 times longer than the substance it was compared with. In a second study including 7 normal subjects and 5 patients with keratoconjunctivitis sicca, the influence of Vidisic on break-up time (BUT) and the Schirmer test was demonstrated. It was found that tear secretion improved for 2-4 hours (Schirmer test) and the stability of the tear film (BUT) improved for about 6 hours with Vidisic. These results suggest that application of Vidisic four times a day is sufficient for efficatious therapy even in cases of severe keratoconjunctivitis sicca.