title: The influence of central corneal thickness on response to topical prostaglandin analogue therapy.
abstract: OBJECTIVE
  Central corneal thickness (CCT) affects intraocular pressure (IOP) readings; however, CCT influence on topical medication efficacy is unknown. We evaluated the IOP-lowering effect of topical prostaglandin analogues (PGAs) in relation to CCT.
  
  
  METHODS
  Post hoc analysis of a randomized prospective trial.
  
  
  METHODS
  Subjects randomized to a PGA were followed for 24 weeks and were analyzed for relationship between CCT and IOP lowering.
  
  
  METHODS
  Patients with either newly diagnosed ocular hypertension or open-angle glaucoma.
  
  
  RESULTS
  75 subjects were enrolled. The mean age was 62.7 ± 10.5 years; 48 were Caucasian. The mean CCT was 562.4 ± 41.4 μ. At repeated measures, ANCOVA analysis showed a significant effect of both baseline IOP (p < 0.0001) and CCT (p = 0.003) on IOP. At week 12, a regression analysis of the effect of CCT on baseline IOP showed that for every 10 μ increase in CCT there was 0.3 mm Hg less IOP decrease from baseline.
  
  
  CONCLUSIONS
  We found a statistically significantly association between a lower mean IOP and a thinner cornea when baseline IOP is controlled for. The magnitude of the relationship is small but may be clinically significant in patients with either very thin or very thick corneas.
authors.affiliation: Department of Ophthalmology & Vision Sciences, University of Toronto, Toronto, Ont. catherine.birt@sunnybrook.ca
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Birt
authors.forename: Yvonne M
authors.initials: YM
authors.lastname: Buys
authors.forename: Alex
authors.initials: A
authors.lastname: Kiss
authors.forename: Graham E
authors.initials: GE
authors.lastname: Trope
mesh_terms: D000287:Administration, Topical; D000577:Amides / Q000008:administration & dosage*; D000959:Antihypertensive Agents / Q000008:administration & dosage*; D000069580:Bimatoprost; D003008:Cloprostenol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D003315:Cornea / Q000187:drug effects / Q000473:pathology*; D005260:Female; D005902:Glaucoma, Open-Angle / Q000188:drug therapy* / Q000208:ethnology; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D000077338:Latanoprost; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000188:drug therapy / Q000208:ethnology; D011446:Prospective Studies; D011461:Prostaglandins F, Synthetic / Q000008:administration & dosage*; D014065:Tonometry, Ocular; D000069557:Travoprost; D016896:Treatment Outcome
chemical_list: D000577:Amides; D000959:Antihypertensive Agents; D011461:Prostaglandins F, Synthetic; D003008:Cloprostenol; D000077338:Latanoprost; D000069580:Bimatoprost; D000069557:Travoprost