title: Peak intraocular pressure and glaucomatous progression in primary open-angle glaucoma.
abstract: OBJECTIVE
  To evaluate the effect of 24-h peak intraocular pressure (IOP) on the progression of primary open-angle glaucoma (POAG) and the 24 h time points that best predict peak pressure.
  
  
  METHODS
  A retrospective analysis of clinical data evaluating long-term glaucomatous progression in patients with POAG who were previously in a 24-h study of the authors (IOP readings at 2/6/10 A.M. and 2/6/10 PM); had ≥3 treated 10 A.M. (±1 h) IOP measurements over 5-years after an untreated 24-h baseline; and had a treated 24-h curve with a 10 A.M. IOP±2 mmHg within the 10 A.M. mean IOP over 5-years.
  
  
  RESULTS
  We included 98 nonprogressed and 53 progressed patients with POAG (n=151). The mean 24-h peak IOP (mmHg) was 19.9±2.7 for progressed and 18.3±2.0 for nonprogressed patients (P<0.001). Progressed patients also showed a higher mean 24-h IOP. Generally, patients with a mean or peak daytime (readings at 10 A.M., 2 and 6 P.M.) or 24-h peak IOP of ≤18 remained nonprogressed in 75%-78% of cases. Further, measuring IOP at night found a higher peak in only 20% of cases, which was ≤2 of the daytime peak in 98% of cases. A multivariate regression analysis showed only 24-h peak IOP as an independent risk factor for progression (P=0.002).
  
  
  CONCLUSIONS
  This study suggests that daytime peak IOP may be clinically important in predicting long-term glaucomatous progression. Further, daytime peak IOP may assist, as much as daytime mean IOP and, in most cases, 24-h peak IOP, in helping to guide long-term treatment in POAG.
authors: Glaucoma Unit, 1st University, Department of Ophthalmology, AHEPA Hospital, Thessaloniki, Greece.
authors: Anastasios G P
authors: AG
authors: Konstas
authors: Luciano
authors: L
authors: Quaranta
authors: Dimitrios G
authors: DG
authors: Mikropoulos
authors: Mayssa B
authors: MB
authors: Nasr
authors: Andrea
authors: A
authors: Russo
authors: Harris A
authors: HA
authors: Jaffee
authors: Jeanette A
authors: JA
authors: Stewart
authors: William C
authors: WC
authors: Stewart
mesh_terms: D000368:Aged; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005902:Glaucoma, Open-Angle / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012044:Regression Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors