title: Long-term effects of timolol therapy in ocular hypertension: a double-masked, randomised trial.
abstract: BACKGROUND
  Increased intraocular pressure (IOP) has been shown to be one of the most important risk factors for developing glaucoma. Yet it has not been clearly demonstrated that IOP-lowering treatment can reduce the incidence of glaucoma damage in patients with ocular hypertension. The aim of the current paper was to report the results of a long-term study addressing this very problem.
  
  
  METHODS
  We conducted a randomised, double-masked study comparing timolol and placebo treatment in 90 patients with ocular hypertension plus some additional risk factor. Patients were followed at 3-month intervals prospectively for 10 years or until glaucomatous field loss could be demonstrated with computerised perimetry. A post-study analysis was performed including all available data, thus extending maximum follow-up to 17 years.
  
  
  RESULTS
  After 5 years of follow-up eight patients in the placebo group and five patients in the timolol group had developed glaucomatous field loss (NS); the corresponding figures after 10 years were 15 patients in the placebo group and seven patients in the timolol group. Survival analysis showed a tendency but no statistically significant difference between treatment groups (P = 0.07). Study attrition was large. Eighteen patients in each group had developed glaucomatous field loss when also post-study data were included. IOP reduction was greater in eyes passing the 10-year visit without field loss (5.7 mmHg), than in those that reached an end-point (2.3 mmHg; P = 0.0002).
  
  
  CONCLUSIONS
  In this long-term study we found a tendency but failed to prove a beneficial effect of topical timolol treatment in patients with elevated IOP, normal visual fields and some additional risk factor. The intent-to-treat analysis showed no difference between treatment groups. The high attrition shows the difficulties associated with very long follow-up.
authors.affiliation: Department of Ophthalmology, Malmö University Hospital, 20502 Malmö, Sweden. anders.heijl@oftal.mas.lu.se
authors.forename: A
authors.initials: A
authors.lastname: Heijl
authors.forename: B
authors.initials: B
authors.lastname: Bengtsson
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000188:drug therapy*; D009898:Optic Disk / Q000473:pathology; D011446:Prospective Studies; D012307:Risk Factors; D013999:Timolol / Q000627:therapeutic use*; D014065:Tonometry, Ocular; D016896:Treatment Outcome; D014794:Visual Fields
chemical_list: D000319:Adrenergic beta-Antagonists; D013999:Timolol