title: Discrepancy of the intraocular pressure response between fellow eyes in one-eye trials versus bilateral treatment: verification with normal subjects.
abstract: OBJECTIVE
  To compare the correlation of the fellow-eye's intraocular pressure (IOP) response in one-eye trials performed separately for each eye with that of bilateral treatment in normal subjects.
  
  
  METHODS
  A one-eye trial with topical latanoprost applied once daily for 7 days was carried out in the right eye and then in the left eye of 41 normal subjects. Bilateral treatment was performed in a different set of 41 normal subjects. IOPs were measured at 3 time points on day 0 and on day 7.
  
  
  RESULTS
  Latanoprost significantly reduced IOP of treated eyes in one-eye trials (2.8+/-1.6 and 2.7+/-1.6 mm Hg in the first and second trial, respectively) and in bilateral treatments (2.8+/-1.3 and 2.6+/-1.4 mm Hg in the right and left eye, respectively). Correlation of mean diurnal IOP reduction between 2 one-eye trials was poor (r2=0.102), even after subtracting the nontreated eye IOP fluctuations from the treated eye IOPs (r2=0.097), but that between fellow eyes in bilateral treatment was excellent (r=0.849). Correlation of baseline IOP at each time point between fellow eyes in one-eye trials and bilateral treatment (r2=0.729 to 0.949) was better than that in the same eye between 2 one-eye trials (r2=0.319 to 0.631).
  
  
  CONCLUSIONS
  Fellow eyes in normal subjects showed a symmetrical IOP response to short-term bilateral treatment with latanoprost, although they did not respond symmetrically to one-eye trials performed separately for each eye. Poor correlation of IOP changes between 2 one-eye trials may be caused by different IOP responsiveness to latanoprost at each trial, rather than asymmetrical IOP fluctuations.
authors.affiliation: Department of Ophthalmology and Visual Science, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan.
authors.forename: Mami
authors.initials: M
authors.lastname: Takahashi
authors.forename: Tomomi
authors.initials: T
authors.lastname: Higashide
authors.forename: Mayumi
authors.initials: M
authors.lastname: Sakurai
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Sugiyama
mesh_terms: D000287:Administration, Topical; D000328:Adult; D000959:Antihypertensive Agents / Q000008:administration & dosage*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D000077338:Latanoprost; D008297:Male; D011446:Prospective Studies; D011461:Prostaglandins F, Synthetic / Q000008:administration & dosage*; D014065:Tonometry, Ocular
chemical_list: D000959:Antihypertensive Agents; D011461:Prostaglandins F, Synthetic; D000077338:Latanoprost