title: Circadian macular volume changes in the healthy human choroid.
abstract: OBJECTIVE
  To investigate a potential circadian fluctuation of the choroidal volume in healthy adults by enhanced depth imaging (EDI) via spectral-domain optical coherence tomography (SD OCT).
  
  
  METHODS
  Prospective observational case series.
  
  
  METHODS
  Thirty healthy eyes of 15 healthy subjects with a median age of 26 years (range 22-55) underwent EDI SD OCT scans for macular choroidal volume measurement every 3 hours within a 24-hour period at a single tertiary center. The mean ocular perfusion pressure was calculated for each eye at each of the 8 time points as 2/3(mean arterial pressure-intraocular pressure [IOP]). The circadian fluctuation of the macular choroidal volume as well as the association with axial length, mean ocular perfusion pressure, or IOP was assessed using a linear mixed model.
  
  
  RESULTS
  Macular choroidal volume showed a significant circadian fluctuation (P < .05) and was lowest at midday (mean ± SD, 10.14 ± 2.62 mm(3)) and highest at 3 AM (mean ± SD, 10.66 ± 2.70 mm(3)). Of all factors tested, only mean ocular perfusion pressure showed a significant association with macular choroidal volume fluctuation (P = .016).
  
  
  CONCLUSIONS
  Macular choroidal volume shows a significant circadian pattern with higher values at night and lower values during the day in young adults. Besides time, mean ocular perfusion pressure is significantly associated with this fluctuation.
authors.affiliation: Department of Ophthalmology, Medical University of Graz/Austria, Graz, Austria. Electronic address: gerald.seidel@medunigraz.at.
authors.forename: Gerald
authors.initials: G
authors.lastname: Seidel
authors.affiliation: Department of Ophthalmology, Medical University of Graz/Austria, Graz, Austria.
authors.forename: Silke
authors.initials: S
authors.lastname: Hausberger
authors.affiliation: Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz/Austria, Graz, Austria.
authors.forename: Sereina Annik
authors.initials: SA
authors.lastname: Herzog
authors.affiliation: Department of Ophthalmology, Medical University of Graz/Austria, Graz, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Palkovits
authors.affiliation: Department of Ophthalmology, Medical University of Graz/Austria, Graz, Austria.
authors.forename: Eva Maria
authors.initials: EM
authors.lastname: Pöschl
authors.affiliation: Department of Ophthalmology, Medical University of Graz/Austria, Graz, Austria.
authors.forename: Werner
authors.initials: W
authors.lastname: Wackernagel
authors.affiliation: Department of Ophthalmology, Medical University of Graz/Austria, Graz, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Weger
mesh_terms: D000328:Adult; D062186:Arterial Pressure / Q000502:physiology; D058452:Axial Length, Eye / Q000033:anatomy & histology; D002829:Choroid / Q000033:anatomy & histology*; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult