title: Short-term reproducibility of intraocular pressure and ocular perfusion pressure measurements in Chinese volunteers and glaucoma patients.
abstract: BACKGROUND
  To evaluate the short-term reproducibility of diurnal intraocular pressure (IOP) and ocular perfusion pressure (OPP) measurements in normal volunteers, untreated normal-tension glaucoma (NTG) and primary open-angle glaucoma (POAG) patients.
  
  
  METHODS
  Fifty-four healthy volunteers (control group), 67 NTG patients and 54 POAG patients were recruited. The IOPs of both eyes were measured with a Goldmann applanation tonometer at 3-h intervals over 2 consecutive days. Blood pressure (BP) measurements were collected at the same times. The mean IOP/OPP, peak IOP/OPP, trough IOP/OPP and IOP/OPP fluctuations on each day were also calculated. The intraclass correlation coefficients (ICCs) were used to evaluate the reproducibilities.
  
  
  RESULTS
  In the control group, the ICCs of mean IOP, peak IOP, trough IOP and IOP fluctuation were 0.921, 0.889, 0.888, and 0.661, respectively, and the ICCs of the mean OPP, peak OPP, trough OPP and OPP fluctuations were 0.962, 0.918, 0.953, and 0.680, respectively. In the NTG group, the ICCs of the mean IOP, peak IOP, trough IOP and IOP fluctuation were 0.862, 0.741, 0.798, and 0.290, respectively, and the ICCs of the mean OPP, peak OPP, trough OPP and OPP fluctuations were 0.947, 0.828, 0.927, and -0.008, respectively. In the POAG group, the ICCs of the mean IOP, peak IOP, trough IOP and IOP fluctuation were 0.857, 0.666, 0.808, and 0.546, respectively, and the ICCs of the mean OPP, peak OPP, trough OPP and OPP fluctuation were 0.934, 0.842, 0.910, and 0.093, respectively.
  
  
  CONCLUSIONS
  The IOP measurements within a single day were not highly reproducible in the short-term. The normal volunteers exhibited better IOP and OPP reproducibilities than the glaucoma patients. The IOP and OPP fluctuations could not be accurately evaluated based on the IOP or OPP measurements within a single day.
authors.affiliation: Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Vision Science, Clinical College of Ophthalmology, Tianjin Medical University, 4, Gansu Road, Heping District, Tianjin, 300020, People's Republic of China.
authors.forename: Yanlin
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Laboratory, Central Hospital Affiliated to Shenyang Medical College, Shenyang, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Wan
authors.affiliation: Department of Ophthalmology, the Second Hospital Affiliated to Dalian Medical University, Dalian, China.
authors.forename: Peiyu
authors.initials: P
authors.lastname: Li
authors.affiliation: Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Vision Science, Clinical College of Ophthalmology, Tianjin Medical University, 4, Gansu Road, Heping District, Tianjin, 300020, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Vision Science, Clinical College of Ophthalmology, Tianjin Medical University, 4, Gansu Road, Heping District, Tianjin, 300020, People's Republic of China. 34830277@qq.com.
authors.forename: Xin
authors.initials: X
authors.lastname: Tang
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001794:Blood Pressure / Q000502:physiology; D016022:Case-Control Studies; D002940:Circadian Rhythm / Q000502:physiology; D005260:Female; D005902:Glaucoma, Open-Angle / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D057066:Low Tension Glaucoma / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000503:physiopathology; D015203:Reproducibility of Results; D014065:Tonometry, Ocular