title: Rate of response to latanoprost or timolol in patients with ocular hypertension or glaucoma.
abstract: OBJECTIVE
  This study determined the rate of response to latanoprost compared with timolol in patients with glaucoma or ocular hypertension, whether some patients convert from non-responders to responders after more prolonged therapy, and whether this conversion represents a delayed response or random fluctuation.
  
  
  METHODS
  In a previously described, multicenter, randomized, double-masked, parallel group study, patients received either 0.005% latanoprost once daily (n = 128) or 0.5% timolol twice daily (n = 140) for 6 months. Intraocular pressure (IOP) was assessed at baseline and at 0.5, 1.5, 3, 4.5, and 6 months of treatment at 8 am on all visits, and also at noon and 4 pm at baseline and 6 months. Rate of response based on diurnal measurement at 6 months compared with baseline was assessed using several criteria for response. Eyes with an IOP reduction of less than 15% compared with baseline at 8 am arbitrarily were classified as non-responders at each of the 5 visits during treatment. Consistency of non-responder classifications for individual eyes was assessed.
  
  
  RESULTS
  Mean IOP reduction was greater (P < 0.001) in latanoprost-versus timolol-treated patients throughout the course of therapy. A greater rate of response occurred in patients treated with latanoprost, and differences in response rates between the 2 drugs increased as the definitions of response became more stringent. A greater percentage of non-responders at any single visit were classified as responders at all other visits with latanoprost in comparison with timolol.
  
  
  CONCLUSIONS
  Latanoprost produces a greater rate of response compared with timolol. A higher percentage of non-responders to latanoprost compared with timolol on any individual visit are responders on all other visits. Likewise, a higher proportion of patients who do not initially respond will become responders with continued treatment with latanoprost compared with timolol.
authors.affiliation: Department of Ophthalmology, University of Nebraska medical Center, Omaha, Nebraska 68198-5540, USA. cbcamras@unmc.edu
authors.forename: Carl B
authors.initials: CB
authors.lastname: Camras
authors.forename: Katarina
authors.initials: K
authors.lastname: Hedman
mesh_terms: D000959:Antihypertensive Agents / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D004351:Drug Resistance; D005901:Glaucoma / Q000188:drug therapy*; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D000077338:Latanoprost; D009798:Ocular Hypertension / Q000188:drug therapy; D011461:Prostaglandins F, Synthetic / Q000627:therapeutic use*; D013999:Timolol / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D000959:Antihypertensive Agents; D011461:Prostaglandins F, Synthetic; D000077338:Latanoprost; D013999:Timolol