title: Average versus highest intraocular pressure analyses in glaucoma clinical trials.
abstract: OBJECTIVE
  To evaluate methods which account for both eyes as a single, independent variable in glaucoma clinical trials.
  
  
  METHODS
  A review of clinical trial articles published between January 1995 and April 2011 evaluating currently used topical glaucoma medications.
  
  
  RESULTS
  This analysis included 17 articles with 36 treatment arms of which 14 were prostaglandins, 13 β-blockers, 6 topical carbonic anhydrase inhibitors and 3 α-agonists. Twenty-four articles used average intraocular pressure (IOP) analysis, 12 used the highest IOP analysis and none utilized the randomized eye method. At untreated baseline, there was a difference in the IOP between average IOP and highest baseline IOP analyses at 8 a.m. (p = 0.001) and for the diurnal curve (p = 0.02) as well as specifically for β-blockers (p = 0.002) at 8 a.m. and β-blockers for the diurnal curve (p = 0.01).
  
  
  CONCLUSIONS
  This study suggests that the highest IOP analysis method generally provides slightly higher IOPs at baseline than the average IOP analysis method.
authors.affiliation: Department of Ophthalmology, Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: DeMill
authors.forename: Barbara M
authors.initials: BM
authors.lastname: Wirostko
authors.forename: Lindsay A
authors.initials: LA
authors.lastname: Nelson
authors.forename: Jeanette A
authors.initials: JA
authors.lastname: Stewart
authors.forename: William C
authors.initials: WC
authors.lastname: Stewart
mesh_terms: D000704:Analysis of Variance; D000959:Antihypertensive Agents / Q000627:therapeutic use; D002986:Clinical Trials as Topic; D005901:Glaucoma / Q000188:drug therapy / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D017063:Outcome Assessment, Health Care / Q000379:methods
chemical_list: D000959:Antihypertensive Agents