title: Three-dimensional automated choroidal volume assessment on standard spectral-domain optical coherence tomography and correlation with the level of diabetic macular edema.
abstract: OBJECTIVE
  To measure choroidal thickness on spectral-domain optical coherence tomography (SD OCT) images using automated algorithms and to correlate choroidal pathology with retinal changes attributable to diabetic macular edema (DME).
  
  
  METHODS
  Post hoc analysis of multicenter clinical trial baseline data.
  
  
  METHODS
  SD OCT raster scans/fluorescein angiograms were obtained from 284 treatment-naïve eyes of 142 patients with clinically significant DME and from 20 controls. Three-dimensional (3D) SD OCT images were evaluated by a certified independent reading center analyzing retinal changes associated with diabetic retinopathy. Choroidal thicknesses were analyzed using a fully automated algorithm. Angiograms were assessed manually. Multiple endpoint correction according to Bonferroni-Holm was applied. Main outcome measures were average retinal/choroidal thickness on fovea-centered or peak of edema (thickest point of edema)-centered Early Treatment Diabetic Retinopathy Study grid, maximum area of leakage, and the correlation between retinal and choroidal thicknesses.
  
  
  RESULTS
  Total choroidal thickness is significantly reduced in DME (175 ± 23 μm; P = .0016) and nonedematous fellow eyes (177 ± 20 μm; P = .009) of patients compared with healthy control eyes (190 ± 23 μm). Retinal/choroidal thickness values showed no significant correlation (1-mm: P = .27, r(2) = 0.01; 3-mm: P = .96, r(2) < 0.0001; 6-mm: P = .42, r(2) = 0.006). No significant difference was found in the 1- or 3-mm circle of a retinal peak of edema-centered grid. All other measurements of choroidal/retinal thickness (DME vs healthy, DME vs peak of edema-centered, DME vs fellow, healthy vs fellow, peak of edema-centered vs healthy, peak of edema-centered vs fellow eyes) were compared but no statistically significant correlation was found. By tendency a thinner choroid correlates with larger retinal leakage areas.
  
  
  CONCLUSIONS
  Automated algorithms can be used to reliably assess choroidal thickness in eyes with DME. Choroidal thickness was generally reduced in patients with diabetes if DME is present in 1 eye; however, no correlation was found between choroidal/retinal pathologies, suggesting different pathogenetic pathways.
authors.affiliation: Vienna Reading Center, Department of Ophthalmology, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Ophthalmic Image Analysis, Medical University of Vienna, Vienna, Austria.
authors.forename: Bianca S
authors.initials: BS
authors.lastname: Gerendas
authors.affiliation: Vienna Reading Center, Department of Ophthalmology, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Ophthalmic Image Analysis, Medical University of Vienna, Vienna, Austria.
authors.forename: Sebastian M
authors.initials: SM
authors.lastname: Waldstein
authors.affiliation: Vienna Reading Center, Department of Ophthalmology, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Ophthalmic Image Analysis, Medical University of Vienna, Vienna, Austria. Electronic address: optima@meduniwien.ac.at.
authors.forename: Christian
authors.initials: C
authors.lastname: Simader
authors.affiliation: Vienna Reading Center, Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.
authors.forename: Gabor
authors.initials: G
authors.lastname: Deak
authors.affiliation: Vienna Reading Center, Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.
authors.forename: Bilal
authors.initials: B
authors.lastname: Hajnajeeb
authors.affiliation: Department of Electrical & Computer Engineering, University of Iowa, Iowa City, Iowa.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Electrical & Computer Engineering, University of Iowa, Iowa City, Iowa.
authors.forename: Hrvoje
authors.initials: H
authors.lastname: Bogunovic
authors.affiliation: Department of Electrical & Computer Engineering, University of Iowa, Iowa City, Iowa; Department of Ophthalmology & Visual Sciences, University of Iowa, Iowa City, Iowa; Veterans Affairs, Medical Center, West Iowa City, Iowa.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Abramoff
authors.affiliation: Institute of Environmental Health, Center for Public Health, Medical University of Vienna, Vienna, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Kundi
authors.affiliation: Department of Electrical & Computer Engineering, University of Iowa, Iowa City, Iowa; Department of Ophthalmology & Visual Sciences, University of Iowa, Iowa City, Iowa.
authors.forename: Milan
authors.initials: M
authors.lastname: Sonka
authors.affiliation: Vienna Reading Center, Department of Ophthalmology, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Ophthalmic Image Analysis, Medical University of Vienna, Vienna, Austria.
authors.forename: Ursula
authors.initials: U
authors.lastname: Schmidt-Erfurth
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D002829:Choroid / Q000473:pathology*; D003930:Diabetic Retinopathy / Q000150:complications* / Q000175:diagnosis; D005260:Female; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D006801:Humans; D021621:Imaging, Three-Dimensional; D008269:Macular Edema / Q000175:diagnosis* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012160:Retina / Q000473:pathology; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence / Q000379:methods*