Abstract
Methods: :
20 healthy volunteers were enrolled in the double-blind study: one eye was dropped with 0.01% Benzalconium chloride (BAC) solution, the fellow one - with a placebo. Evaluation of distribution and density of LC in the central and peripheral corneal epithelium as well pachymetry was performed with in vivo confocal laser scanning microscopy. Development of dry eye (complaints of the patient, slit lamp biomicroscopy, break up time (BUT), Schirmer test) was controlled. The volunteers were investigated before the therapy, followed up in 1, 6 and 12 weeks during the medication as well 4 weeks after its termination.
Results: :
In vivo confocal microscopy revealed significant increase of LC density in BAC-group in 6 weeks in central cornea (p=0,03) and in 12 weeks in central (p=0,01) and peripheral cornea (p=0,04). LC density was significantly decreased after the termination of the therapy in both zones. The increase of LC density was significant faster in center as in the periphery (p=0,02 in 12 weeks). The Placebo-group showed no changes of LC density in both zones during the whole study.BAC-group demonstrated signs of the developing of dry eye (reduction of Schirmer test, increase of lid-parallel conjunctival folds by unchanged BUT and constant epithelial thickness). Corneal sensation and intraocular pressures were identical in both groups.
Conclusions: :
The evidence of immune stimulation of the cornea as well as development of dry eye under the BAC-holding therapy proves the necessity of preservative-free medication especially in patients with dry eye, glaucoma, ocular inflammatory diseases, after corneal grafting, etc.
Clinical Trial: :
EudraCT Nr.2006-004908-39
Keywords: cornea: epithelium • cornea: tears/tear film/dry eye • immunomodulation/immunoregulation