TOPICAL TIMOLOL WITH AND WITHOUT BENZALKONIUM CHLORIDE - EPITHELIAL PERMEABILITY AND AUTOFLUORESCENCE OF THE CORNEA IN GLAUCOMA

Epithelial permeability and autofluorescence of the cornea were determ ined by fluorophotometry in 21 patients with open-angle glaucoma or oc ular hypertension using timolol medication with the preservative benza lkonium chloride (BAC) and 2 weeks after changing to timolol medicatio n without BAC. The investigation was performed to determine whether re moval of BAC would reduce toxic effects on the cornea and complaints o f sensations of burning or dry eye. Corneal epithelial permeability de creased significantly after changing medication (mean decrease per pat ient 27%, P=0.025). Corneal autofluorescence increased significantly a fter changing medication suggesting an alteration in corneal metabolis m (mean increase per patient 6%, P=0.003). Timolol without BAC was fou nd to be as effective as timolol with BAC in reducing intraocular pres sure (P=0.4). Removal of BAC from timolol resulted in an improvement o f corneal epithelial barrier function and in a reduction of complaints . The improvement was found to be proportional to the duration of the preceding BAC-containing therapy.