title: Inter-visit intraocular pressure range: an alternative parameter for assessing intraocular pressure control in clinical trials.
abstract: OBJECTIVE
  To evaluate whether inter-visit intraocular pressure (IOP) range, which reflects extreme and potentially damaging IOP fluctuations, provides additional information on IOP control compared to mean IOP.
  
  
  METHODS
  Post hoc analysis of Xalatan/Lumigan/Travatan study data, a masked-evaluator, randomized, parallel-group comparison of 12-week efficacy of latanoprost, bimatoprost, and travoprost in open-angle glaucoma/ocular hypertension patients.
  
  
  METHODS
  Pretreatment inter-visit IOP range defined as highest IOP minus lowest IOP at screening, safety check, and baseline (six measurements); posttreatment inter-visit IOP range defined as highest IOP minus lowest IOP at weeks two, six, and 12 or early termination (nine measurements). Ranges dichotomized as "high" (>6 mm Hg) vs "low" (< or =6 mm Hg).
  
  
  RESULTS
  Included were 410 patients (latanoprost, 136; bimatoprost, 136; travoprost, 138). Each resulted in significant mean IOP range reductions during 12 weeks. Pretreatment inter-visit IOP range was associated with African-American race, male gender, and presence of visual field defect (P < .05 for all). Percentages with high pretreatment inter-visit IOP ranges were comparable across treatments (63% to 64%). High posttreatment inter-visit IOP range was seen in 21% (28/136), 28% (38/136), and 36% (50/138) of latanoprost, bimatoprost, and travoprost groups, respectively (P = .016, overall; P = .005, latanoprost vs travoprost). High posttreatment inter-visit IOP range was associated with African-American race, high pretreatment inter-visit IOP range, and treatment with travoprost vs latanoprost (P < .05 for all).
  
  
  CONCLUSIONS
  Given that high inter-visit IOP range is associated with risk factors for glaucomatous damage and that such differences cannot be evaluated using mean IOPs, inter-visit IOP range may be another useful approach to assessing IOP control in clinical trials.
authors.affiliation: Keck School of Medicine, University of Southern California, 1450 San Pablo Street, Los Angeles, CA 90033, USA. rvarma@usc.edu
authors.forename: Rohit
authors.initials: R
authors.lastname: Varma
authors.forename: Lie-Ju
authors.initials: LJ
authors.lastname: Hwang
authors.forename: John W
authors.initials: JW
authors.lastname: Grunden
authors.forename: Gerald W
authors.initials: GW
authors.lastname: Bean
mesh_terms: D000368:Aged; D000577:Amides / Q000627:therapeutic use; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D000069580:Bimatoprost; D003008:Cloprostenol / Q000031:analogs & derivatives / Q000627:therapeutic use; D004311:Double-Blind Method; D005260:Female; D005902:Glaucoma, Open-Angle / Q000188:drug therapy* / Q000208:ethnology; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D000077338:Latanoprost; D008055:Lipids / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000188:drug therapy / Q000208:ethnology; D009819:Office Visits; D009883:Ophthalmic Solutions / Q000627:therapeutic use; D011461:Prostaglandins F, Synthetic / Q000627:therapeutic use; D012307:Risk Factors; D000069557:Travoprost; D016896:Treatment Outcome
chemical_list: D000577:Amides; D000959:Antihypertensive Agents; D008055:Lipids; D009883:Ophthalmic Solutions; D011461:Prostaglandins F, Synthetic; D003008:Cloprostenol; D000077338:Latanoprost; D000069580:Bimatoprost; D000069557:Travoprost