title: Circadian changes of intraocular pressure and ocular perfusion pressure after timolol or latanoprost in Caucasians with normal-tension glaucoma.
abstract: OBJECTIVE
  To evaluate the circadian effects on intraocular pressure (IOP) and ocular perfusion pressure (OPP) of 0.5% timolol or 0.005% latanoprost in Caucasian patients affected by normal-tension glaucoma (NTG).
  
  
  METHODS
  In this crossover trial, 30 consecutive NTG subjects underwent three 24-hour assessments of IOP, blood pressure (BP), heart rate (HR), and OPP [calculated according to the formula OPP = (1/3 systolic BP + 2/3 diastolic BP) x 2/3 - IOP]: at baseline, and after 1-month treatment with timolol or latanoprost. These parameters were recorded at 4 a.m., 8 a.m., noon, 4 p.m., 8 p.m., and midnight.
  
  
  RESULTS
  Both timolol and latanoprost reduced IOP (p < 0.001), with a difference in favour of latanoprost of 1.3 mmHg (95% CI 0.9, 1.6; p < 0.001). After timolol, BP and HR decreased with respect to baseline (p < 0.001). Latanoprost increased mean OPP (3.6 mmHg, 95% CI 2.9, 4.3; p < 0.001), whereas timolol did not improve it.
  
  
  CONCLUSIONS
  Latanoprost induces an IOP reduction greater than timolol, also achieving a better circadian flattening of the IOP curve. Only latanoprost significantly increased mean 24-hour OPP. The management of Caucasian NTG patients should be critically realized, considering the 24-hour influence of each IOP-lowering drug on the ocular blood perfusion.
authors.affiliation: Department of Ophthalmology, University of Ferrara, Ferrara, Italy.
authors.forename: Ciro
authors.initials: C
authors.lastname: Costagliola
authors.forename: Francesco
authors.initials: F
authors.lastname: Parmeggiani
authors.forename: Gianni
authors.initials: G
authors.lastname: Virgili
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lamberti
authors.forename: Carlo
authors.initials: C
authors.lastname: Incorvaia
authors.forename: Paolo
authors.initials: P
authors.lastname: Perri
authors.forename: Claudio
authors.initials: C
authors.lastname: Campa
authors.forename: Adolfo
authors.initials: A
authors.lastname: Sebastiani
mesh_terms: D000287:Administration, Topical; D000368:Aged; D000959:Antihypertensive Agents / Q000008:administration & dosage*; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D002940:Circadian Rhythm / Q000187:drug effects* / Q000502:physiology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D005902:Glaucoma, Open-Angle / Q000188:drug therapy* / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects* / Q000502:physiology; D000077338:Latanoprost; D008297:Male; D008875:Middle Aged; D011461:Prostaglandins F, Synthetic / Q000008:administration & dosage; D013999:Timolol / Q000008:administration & dosage; D044465:White People
chemical_list: D000959:Antihypertensive Agents; D011461:Prostaglandins F, Synthetic; D000077338:Latanoprost; D013999:Timolol