title: Circadian Intraocular Pressure Fluctuation and Disease Progression in Primary Angle Closure Glaucoma.
abstract: OBJECTIVE
  To document the continuous circadian intraocular pressure (IOP) fluctuation using a contact lens sensor during normal daily activities, and to study the relationship between IOP fluctuation and disease progression in primary angle closure glaucoma (PACG) eyes.
  
  
  METHODS
  Circadian IOP fluctuations were recorded by Sensimed Triggerfish sensors in 25 PACG eyes. The sensor output signals were smoothed using B-spline smoothing transform and described by functional data analysis. Glaucoma progression was documented with serial changes in mean deviation (MD) and visual field index (VFI) in Humphrey automated perimetry and retinal nerve fiber layer (RNFL) thickness. The signals were compared between the progressive and stable groups by permutation tests on functional t-statistic.
  
  
  RESULTS
  Statistically significant differences were found from 2200 to 2300 and from 0700 to 0800 in gradients of the IOP fluctuation curve, as well as from 2300 to 2400 and 0800 to 0900 in curvatures of the IOP fluctuation curves, between the progressive MD and stable MD groups (P < 0.05). Significant gradient differences were also found from 1500 to 1600 and 0600 to 0800 between the progressive VFI and stable VFI groups, and from 2400 to 0100 and 0200 to 0300 between the progressive RNFL and stable RNFL groups (P < 0.05).
  
  
  CONCLUSIONS
  Significant differences in circadian IOP fluctuation between progressive and stable PACG eyes were identified. Large IOP fluctuations may be associated with disease progression in PACG eyes.
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China 2Department of Ophthalmology, Chinese PLA General Hospital, Beijing, China.
authors.forename: Shaoying
authors.initials: S
authors.lastname: Tan
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China 3Department of Mathematics and Statistics, Hang Seng Management College, Hong Kong SAR, China.
authors.forename: Marco
authors.initials: M
authors.lastname: Yu
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China 4Hong Kong Eye Hospital, Kowloon, Hong Kong SAR, China.
authors.forename: Nafees
authors.initials: N
authors.lastname: Baig
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China 4Hong Kong Eye Hospital, Kowloon, Hong Kong SAR, China.
authors.forename: Poemen Pui-man
authors.initials: PP
authors.lastname: Chan
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China.
authors.forename: Fang Yao
authors.initials: FY
authors.lastname: Tang
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China 4Hong Kong Eye Hospital, Kowloon, Hong Kong SAR, China 5Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Shatin, Hong Kong.
authors.forename: Clement C
authors.initials: CC
authors.lastname: Tham
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002940:Circadian Rhythm; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D015812:Glaucoma, Angle-Closure / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D041623:Tomography, Optical Coherence; D014065:Tonometry, Ocular; D014794:Visual Fields