Thepaper discusses preclinical tests of anewviscoelastic preparation forophthalmosurgery. Experiments revealed that preparationDuo-Bonharen whichcontains hyaluronic acid prepared by bacterial fermentation is suited for clinical tests. After a 24-hour interval following administration into the anterior chamber it does not raise intraocular pressure. In experiments it has no side-effects on the eye. The dispersed form in a higher concentration (5 %) adheres verywell to ocular tissues and protects them adequately during surgery. The cohesive form in an optimal concentration (1.5 %) can be rapidly removed from inside the eye. The properties of Duo-Bonharen in experiments are comparable with similar viscomaterials which are used. The new viscoelastic material Duo-Bonharen appears suitable for clinical tests in particular for cataract surgery.

        Key words: hyaluronic acid, viscomaterial, microsurgery of the eye