title: The negative correlation between age and intraocular pressures measured nyctohemerally in elderly normal-tension glaucoma patients.
abstract: OBJECTIVE
  To evaluate the correlation between age and intraocular pressure (IOP) measured every 3 h for 24 h in older normal-tension glaucoma (NTG) patients.
  
  
  METHODS
  Ninety consecutive patients suspected of having NTG on the basis of both visual field defect and disc appearance were hospitalized for measurement of nyctohemeral IOP every 3 h over a 24-h period with a Goldmann tonometer after a 4-week wash-out of any existing medication. Sixty-nine patients (76.7%) were diagnosed as having NTG. Sixty-nine eyes of 69 subjects were enrolled for this prospective, cross-sectional study. They were divided into two groups by age (cut-off between 59 and 60 years: group 1, under 60 years; group 2, over 60 years). The correlations between age and the mean, maximum and minimum IOP and IOP variation of the eight nyctohemeral IOP measurements nyctohemerally were evaluated for each group. The times of day at which the maximum and minimum IOPs were observed were recorded.
  
  
  RESULTS
  Groups 1 and 2 consisted of 28 patients (age: 50.2+/-6.1 years) and 42 patients (age: 70.3+/-6.1 years) ( P<0.0001), respectively. Neither mean, maximum or minimum IOP nor the IOP variation was significantly different between the groups (all P values > or =0.115). The mean, maximum and minimum IOP in group 2 were all correlated with age ( n=41; r=-0.516, P=0.0004; r=-0.434, P=0.004; r=-0.522, P=0.0004, respectively), while none of those in group 1 was correlated with age (all P values > or =0.303).
  
  
  CONCLUSIONS
  The IOPs of the elder NTG patients have a negative correlation with age while those of the younger ones have no relation to age.
authors.affiliation: Department of OphthalmologyHiroshima University School of Medicine, 1-2-3 Kasumi, Minami-ku, 734-8551, Hiroshima, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Okada
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Tsumamoto
authors.forename: Makiko
authors.initials: M
authors.lastname: Yamasaki
authors.forename: Michiya
authors.initials: M
authors.lastname: Takamatsu
authors.forename: Hiromu K
authors.initials: HK
authors.lastname: Mishima
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D005902:Glaucoma, Open-Angle / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014065:Tonometry, Ocular