title: Symmetry of fellow-eye intraocular pressure responses to topical glaucoma medications.
abstract: OBJECTIVE
  One assumption of the uniocular drug trial in glaucoma management is that fellow-eye pairs exhibit symmetric intraocular pressure (IOP) responses when both eyes are treated with the same topical IOP-lowering medication. The purpose of this study was to determine if this assumption is true.
  
  
  METHODS
  Observational case series.
  
  
  METHODS
  Forty-three patients with bilateral glaucoma or ocular hypertension who underwent bilateral treatment with a topical IOP-lowering medication.
  
  
  METHODS
  Patients were on 0 (81%) or 1 (19%) IOP-lowering medication at the time the medication was added in this study. Baseline IOP was the IOP at the treatment initiation visit, and IOP on treatment was assessed in both eyes on the first visit after addition of the medication. Linear regression of right-eye versus left-eye IOP reductions was performed.
  
  
  METHODS
  Correlation of right-eye and left-eye IOP responses to therapy.
  
  
  RESULTS
  Right eyes demonstrated a 5.0-mmHg (26.9%) reduction, and left eyes demonstrated a 4.3-mmHg (23.7%) reduction. Linear regression of right-eye IOP reduction against left-eye IOP reduction gave a slope of 0.77 (Pearson correlation coefficient, r = 0.84; r2 = 0.70; P<0.0001).
  
  
  CONCLUSIONS
  Fellow-eye pairs exhibited marked symmetry in IOP responses to IOP-lowering medications.
authors.affiliation: Department of Ophthalmology, West Virginia University Eye Institute, Morgantown, West Virginia 26506, USA. realinia@rcbhsc.wvu.edu
authors.forename: Tony
authors.initials: T
authors.lastname: Realini
authors.forename: W Rob
authors.initials: WR
authors.lastname: Vickers
mesh_terms: D000287:Administration, Topical; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D005260:Female; D007839:Functional Laterality; D005902:Glaucoma, Open-Angle / Q000188:drug therapy*; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000188:drug therapy; D012107:Research Design
chemical_list: D000959:Antihypertensive Agents