EFFECT OF CONTINUED TREATMENT WITH TIMOLOL MALEATE ON CORNEAL ENDOTHELIUM - A FLUOROPHOTOMETRIC STUDY

Purpose. To verify whether the long-term use of timolol maleate is tox ic for the corneal endothelium and whether the treatment time is a pre disposing factor. Methods. We used fluorophotometry to study 40 eyes t hat had been treated with timolol maleate uninterruptedly during a pro longed time (from 6 months to 14 years). The results obtained were com pared with a sample of 40 hypertensive eyes that had not received any treatment. Results. No statistically significant differences were foun d between the coefficient values of endothelial permeability between t he treated and nontreated subjects. In addition, no differences were f ound in the coefficient of endothelial permeability between subjects t reated with timolol in different treatment periods (between 6 and 12 m onths, between 1 and 5 years, and for >5 years). Conclusion. These res ults suggest that longterm treatment with timolol has little effect on the integrity of the corneal endothelium.