title: Effect of continued treatment with timolol maleate on corneal endothelium: a fluorophotometric study.
abstract: OBJECTIVE
  To verify whether the long-term use of timolol maleate is toxic for the corneal endothelium and whether the treatment time is a predisposing factor.
  
  
  METHODS
  We used fluorophotometry to study 40 eyes that had been treated with timolol maleate uninterruptedly during a prolonged time (from 6 months to 14 years). The results obtained were compared with a sample of 40 hypertensive eyes that had not received any treatment.
  
  
  RESULTS
  No statistically significant differences were found between the coefficient values of endothelial permeability between the treated and nontreated subjects. In addition, no differences were found in the coefficient of endothelial permeability between subjects treated with timolol in different treatment periods (between 6 and 12 months, between 1 and 5 years, and for > 5 years).
  
  
  CONCLUSIONS
  These results suggest that long-term treatment with timolol has little effect on the integrity of the corneal endothelium.
authors.affiliation: Department of Ophthalmology, Severo Ochoa Hospital, Madrid, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Beneyto
authors.forename: T M
authors.initials: TM
authors.lastname: Pérez
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D004728:Endothelium, Corneal / Q000187:drug effects* / Q000378:metabolism; D019793:Fluorescein / Q000378:metabolism; D015590:Fluorophotometry; D005500:Follow-Up Studies; D005901:Glaucoma / Q000188:drug therapy; D006801:Humans; D008875:Middle Aged; D009883:Ophthalmic Solutions; D010539:Permeability / Q000187:drug effects; D013999:Timolol / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D000959:Antihypertensive Agents; D009883:Ophthalmic Solutions; D013999:Timolol; D019793:Fluorescein