title: Long-term Reliability of Diurnal Intraocular Pressure Patterns in Healthy Asians.
abstract: OBJECTIVE
  To determine the long-term repeatability of diurnal intraocular pressure (IOP) patterns in healthy Asian subjects without glaucoma.
  
  
  METHODS
  Twenty-three eyes in 23 healthy Asian subjects without glaucoma underwent diurnal IOP measurements using Goldmann applanation tonometry every 2 hours from 9 AM to 11 PM during two visits that were 8 weeks apart. To validate repeatability between visits, we calculated intra-class correlation coefficients (ICCs) mean IOP, peak IOP, minimum IOP, and IOP fluctuation at each time point and expressed the results as the difference between peak IOP and minimum IOP or as the standard deviation of all diurnal IOP values in the diurnal IOP curve.
  
  
  RESULTS
  IOP repeatability was excellent at all time points, with ICCs ranging from 0.812 to 0.946 (p< 0.001). The 9 AM IOP showed the best repeatability between visits (ICCs, 0.946). Repeatability of mean IOP, peak IOP, and minimum IOP was also excellent (ICCs ranging from 0.899 to 0.929). However, IOP fluctuations showed poor repeatability, with an ICC lower than 0.15.
  
  
  CONCLUSIONS
  Long-term repeatability of diurnal IOP patterns in healthy Asian subjects was excellent. These findings suggest that IOP measurements at standardized times of the day will be useful for assessing the effectiveness of glaucoma therapy.
authors.affiliation: Department of Ophthalmology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Yeoun Sook
authors.initials: YS
authors.lastname: Chun
authors.affiliation: Department of Ophthalmology, Kyung Hee University Hospital, Kyung Hee University College of Medicine, Seoul, Korea.
authors.forename: In Ki
authors.initials: IK
authors.lastname: Park
authors.affiliation: Department of Ophthalmology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Ko Un
authors.initials: KU
authors.lastname: Shin
authors.affiliation: Department of Ophthalmology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Joon Mo
authors.initials: JM
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D064368:Healthy Volunteers; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D056910:Republic of Korea; D013997:Time Factors; D055815:Young Adult
keywords: Diurnal rhythm; Intraocular pressure; Repeatability