title: Predicting intraocular pressure change before initiating therapy: timolol versus latanoprost.
abstract: OBJECTIVE
  To study intraocular pressure (IOP) reductions with timolol and latanoprost reached in clinical practice, taking into account data that are routinely collected by the ophthalmologist; to predict IOP reduction from these variables.
  
  
  METHODS
  A cohort of patients with primary open-angle glaucoma (suspect) or ocular hypertension was recruited from nine Dutch centres. Mean absolute and relative IOP reduction was calculated in order to compare timolol to latanoprost. IOP reduction was calculated by comparing patients with certain characteristics to those who had none.
  
  
  RESULTS
  One hundred and fifty-six persons started on timolol and 76 started on latanoprost monotherapy. Mean [95% confidence interval (CI)] absolute reduction was 7.2 mmHg (7.9; 6.5) for timolol and 6.9 mmHg (8.0; 5.8) for latanoprost. Mean relative reduction (95% CI) was 27.2% (29.3; 25.1) for timolol and 26.6% (30.2; 22.9) for latanoprost. No significant difference in IOP reduction between timolol and latanoprost was found when adjusting for data that are routinely collected by the ophthalmologist. At the time of starting treatment, none of these items normally used for the management of glaucoma, except IOP at baseline, could predict change in IOP.
  
  
  CONCLUSIONS
  In clinical practice, timolol and latanoprost achieve similar IOP reductions that are comparable to those achieved in randomized trials. No clinically relevant information for glaucoma management can be used to predict IOP reduction accurately.
authors.affiliation: Department of Epidemiology, Maastricht University, The Netherlands.
authors.forename: Rikkert
authors.initials: R
authors.lastname: van der Valk
authors.forename: Carroll A B
authors.initials: CA
authors.lastname: Webers
authors.forename: Fred
authors.initials: F
authors.lastname: Hendrikse
authors.forename: Stefan C
authors.initials: SC
authors.lastname: de Vogel
authors.forename: Martin H
authors.initials: MH
authors.lastname: Prins
authors.forename: Jan S A G
authors.initials: JS
authors.lastname: Schouten
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000959:Antihypertensive Agents / Q000008:administration & dosage*; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D005902:Glaucoma, Open-Angle / Q000188:drug therapy* / Q000453:epidemiology / Q000503:physiopathology; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D000077338:Latanoprost; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015995:Prevalence; D011461:Prostaglandins F, Synthetic / Q000008:administration & dosage*; D013999:Timolol / Q000008:administration & dosage*
chemical_list: D000959:Antihypertensive Agents; D011461:Prostaglandins F, Synthetic; D000077338:Latanoprost; D013999:Timolol