title: Differentiation of Diabetic Macular Edema From Pseudophakic Cystoid Macular Edema by Spectral-Domain Optical Coherence Tomography.
abstract: OBJECTIVE
  To differentiate diabetic macular edema (DME) from pseudophakic cystoid macular edema (PCME) based solely on spectral-domain optical coherence tomography (SD-OCT).
  
  
  METHODS
  This cross-sectional study included 134 participants: 49 with PCME, 60 with DME, and 25 with diabetic retinopathy (DR) and ME after cataract surgery. First, two unmasked experts classified the 25 DR patients after cataract surgery as either DME, PCME, or mixed-pattern based on SD-OCT and color-fundus photography. Then all 134 patients were divided into two datasets and graded by two masked readers according to a standardized reading-protocol. Accuracy of the masked readers to differentiate the diseases based on SD-OCT parameters was tested. Parallel to the masked readers, a computer-based algorithm was established using support vector machine (SVM) classifiers to automatically differentiate disease entities.
  
  
  RESULTS
  The masked readers assigned 92.5% SD-OCT images to the correct clinical diagnose. The classifier-accuracy trained and tested on dataset 1 was 95.8%. The classifier-accuracy trained on dataset 1 and tested on dataset 2 to differentiate PCME from DME was 90.2%. The classifier-accuracy trained and tested on dataset 2 to differentiate all three diseases was 85.5%. In particular, higher central-retinal thickness/retinal-volume ratio, absence of an epiretinal-membrane, and solely inner nuclear layer (INL)-cysts indicated PCME, whereas higher outer nuclear layer (ONL)/INL ratio, the absence of subretinal fluid, presence of hard exudates, microaneurysms, and ganglion cell layer and/or retinal nerve fiber layer cysts strongly favored DME in this model.
  
  
  CONCLUSIONS
  Based on the evaluation of SD-OCT, PCME can be differentiated from DME by masked reader evaluation, and by automated analysis, even in DR patients with ME after cataract surgery. The automated classifier may help to independently differentiate these two disease entities and is made publicly available.
authors.affiliation: Department of Ophthalmology Medical University of Vienna, Vienna, Austria 2Department of Ophthalmology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States 3Department of Ophthalmology, Inselspital, University Hospital B.
authors.forename: Marion R
authors.initials: MR
authors.lastname: Munk
authors.affiliation: Department of Ophthalmology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, United States.
authors.forename: Lee M
authors.initials: LM
authors.lastname: Jampol
authors.affiliation: Department of Ophthalmology Medical University of Vienna, Vienna, Austria 4Reading Center Vienna, Medical University of Vienna, Vienna, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Simader
authors.affiliation: Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Huf
authors.affiliation: Department of Ophthalmology Medical University of Vienna, Vienna, Austria.
authors.forename: Tamara J
authors.initials: TJ
authors.lastname: Mittermüller
authors.affiliation: Duke Eye Center, Duke Reading Center, Duke University School of Medicine, Durham, North Carolina, United States.
authors.forename: Glenn J
authors.initials: GJ
authors.lastname: Jaffe
authors.affiliation: Department of Ophthalmology Medical University of Vienna, Vienna, Austria.
authors.forename: Ursula
authors.initials: U
authors.lastname: Schmidt-Erfurth
mesh_terms: D003430:Cross-Sectional Studies; D003930:Diabetic Retinopathy / Q000175:diagnosis*; D003937:Diagnosis, Differential; D006801:Humans; D008269:Macular Edema / Q000175:diagnosis*; D019591:Pseudophakia / Q000175:diagnosis*; D016037:Single-Blind Method; D041623:Tomography, Optical Coherence / Q000379:methods*