title: Choroidal thickness measured by spectral domain optical coherence tomography: factors affecting thickness in glaucoma patients.
abstract: OBJECTIVE
  To measure choroidal thickness and to determine parameters associated with it.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Seventy-four glaucoma patients and glaucoma suspects.
  
  
  METHODS
  Spectral domain optical coherence tomography (SD-OCT) scans were obtained to estimate average choroidal thickness in a group of glaucoma suspects and glaucoma patients. The average thickness was calculated from enhanced depth SD-OCT images and manually analyzed with Image J software. Open-angle glaucoma, open-angle glaucoma suspect, primary angle-closure glaucoma, primary angle closure, and primary angle-closure suspect were defined by published criteria. Glaucoma suspects had normal visual fields bilaterally. Glaucoma was defined by specific criteria for optic disc damage and visual field loss in ≥1 eye. The most affected eye was analyzed for comparisons across individuals, and right/left and upper half/lower half comparisons were made to compare thickness against degree of visual field damage.
  
  
  METHODS
  Average macular and peripapillary choroidal thickness measured using SD-OCT.
  
  
  RESULTS
  The choroidal-scleral interface was visualized in 86% and 96% of the macular and peripapillary scans, respectively. In multivariable linear regression analysis, the macular choroid was significantly thinner in association with 4 features: Longer eyes (22 μm per mm longer [95% confidence interval (CI), -33, -11]), older individuals (31 μm thinner per decade older [95% CI, -44, -17]), lower diastolic ocular perfusion pressure (26 μm thinner per 10 mmHg lower [95% CI, 8, 44]), and thicker central corneas (6 μm per 10 μm thicker cornea [95% CI, -10, 0]). The choroid was not significantly thinner in glaucoma patients than in suspects (14 μm [95% CI, -54, 26]; P = 0.5). Peripapillary choroidal thickness was not significantly different between glaucoma and suspect patients. Thickness was not associated with damage severity as estimated by visual field mean deviation or nerve fiber layer thickness, including comparisons of right with left eye or upper with lower values.
  
  
  CONCLUSIONS
  Age, axial length, CCT, and diastolic ocular perfusion pressure are significantly associated with choroidal thickness in glaucoma suspects and glaucoma patients. Degree of glaucoma damage was not consistently associated with choroidal thickness.
  
  
  BACKGROUND
  Proprietary or commercial disclosure may be found after the references.
authors.affiliation: The Glaucoma Service and Dana Center for Preventive Ophthalmology, The Wilmer Eye Institute at Johns Hopkins University, USA. emaul@jhsph.edu
authors.forename: Eugenio A
authors.initials: EA
authors.lastname: Maul
authors.forename: David S
authors.initials: DS
authors.lastname: Friedman
authors.forename: Dolly S
authors.initials: DS
authors.lastname: Chang
authors.forename: Michael V
authors.initials: MV
authors.lastname: Boland
authors.forename: Pradeep Y
authors.initials: PY
authors.lastname: Ramulu
authors.forename: Henry D
authors.initials: HD
authors.lastname: Jampel
authors.forename: Harry A
authors.initials: HA
authors.lastname: Quigley
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology; D058452:Axial Length, Eye / Q000473:pathology; D002829:Choroid / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000175:diagnosis*; D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000175:diagnosis; D009929:Organ Size; D012307:Risk Factors; D041623:Tomography, Optical Coherence; D014786:Vision Disorders / Q000175:diagnosis; D014794:Visual Fields / Q000502:physiology