[Preservative-free timolol eye drops--surface-anesthetic effect and local compatibility].

0.5% timolol without preservative reduces corneal sensitivity for a shorter period of time than timolol with preservative. The subjective tolerance of unpreserved timolol is much better than that of preserved timolol. The latter and 0.5% levobunolol are significantly more poorly tolerated than buffer solution. The smaller the anesthetic side effects, the better the subjective tolerance of the beta-blockers.