title: Relationship of progression of visual field damage to postural changes in intraocular pressure in patients with normal-tension glaucoma.
abstract: OBJECTIVE
  To evaluate whether postural changes of intraocular pressure (IOP) are associated with progression of visual field damage in patients with normal-tension glaucoma (NTG).
  
  
  METHODS
  Prospective, noncomparative, nonrandomized study.
  
  
  METHODS
  Sixty eyes of 33 patients with NTG.
  
  
  METHODS
  Intraocular pressure, blood pressure (BP), and pulse rate (PR) were measured in both sitting and supine positions. Visual fields were examined using Humphrey Field Analyzer (HFA; Zeiss-Humphrey Instruments, Inc., San Leandro, CA). Changes in mean deviation (MD) per year (dB/year), that is, MD slope, were calculated by linear regression analysis of the HFA Statpac 2 program.
  
  
  METHODS
  The relationship between postural changes of IOP and MD slope was analyzed. The correlation between postural changes of IOP and cardiovascular parameters such as BP and PR also was analyzed.
  
  
  RESULTS
  The IOP in the supine position was significantly higher than that in the sitting position (P<0.001, paired t test). There was no significant correlation between MD slope and sitting IOP (Pearson r = 0.172; P = 0.188), but a significant correlation was found between MD slope and supine IOP (r = -0.261; P = 0.043). The MD slope significantly correlated with IOP elevation caused by the postural change (r = -0.682; P<0.001). The systolic BP in the supine position correlated with postural changes of IOP (r = 0.364; P = 0.004), but other cardiovascular parameters did not correlate with IOP parameters.
  
  
  CONCLUSIONS
  The progression of visual field damage in NTG is associated with IOP in the supine position and the magnitude of IOP elevation accompanying postural changes. These results suggest that deterioration in NTG may occur when patients are lying flat during sleep.
authors.affiliation: Department of Ophthalmology, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan. kiuchi-t@md.tsukuba.ac.jp
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kiuchi
authors.forename: Yuta
authors.initials: Y
authors.lastname: Motoyama
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Oshika
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001794:Blood Pressure; D018450:Disease Progression; D005260:Female; D005902:Glaucoma, Open-Angle / Q000188:drug therapy / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011187:Posture; D011446:Prospective Studies; D014065:Tonometry, Ocular; D014786:Vision Disorders / Q000503:physiopathology*; D014792:Visual Acuity; D058609:Visual Field Tests; D014794:Visual Fields
chemical_list: D000959:Antihypertensive Agents