title: Integrative understanding of macular morphologic patterns in diabetic retinopathy based on self-organizing map.
abstract: OBJECTIVE
  To integrate parameters on spectral-domain optical coherence tomography (SD-OCT) in diabetic retinopathy (DR) based on the self-organizing map and objectively describe the macular morphologic patterns.
  
  
  METHODS
  A total of 336 consecutive eyes of 216 patients with DR for whom clear SD-OCT images were available were retrospectively reviewed. Eleven OCT parameters and the logarithm of the minimal angle of resolution (logMAR) were measured. These multidimensional data were analyzed based on the self-organizing map on which similar cases were near each other according to the degree of their similarities, followed by the objective clustering.
  
  
  RESULTS
  Self-organizing maps indicated that eyes with greater retinal thickness in the central subfield had greater thicknesses in the superior and temporal subfields. Eyes with foveal serous retinal detachment (SRD) had greater thickness in the nasal or inferior subfield. Eyes with foveal cystoid spaces were arranged to the left upper corner on the two-dimensional map; eyes with foveal SRD to the left lower corner; eyes with thickened retinal parenchyma to the lower area. The following objective clustering demonstrated the unsupervised pattern recognition of macular morphologies in diabetic macular edema (DME) as well as the higher-resolution discrimination of DME per se. Multiple regression analyses showed better association of logMAR with retinal thickness in the inferior subfield in eyes with SRD and with external limiting membrane disruption in eyes with foveal cystoid spaces or thickened retinal parenchyma.
  
  
  CONCLUSIONS
  The self-organizing map facilitates integrative understanding of the macular morphologic patterns and the structural/functional relationship in DR.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Murakami
authors.forename: Naoko
authors.initials: N
authors.lastname: Ueda-Arakawa
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Nishijima
authors.forename: Akihito
authors.initials: A
authors.lastname: Uji
authors.forename: Takahiro
authors.initials: T
authors.lastname: Horii
authors.forename: Ken
authors.initials: K
authors.lastname: Ogino
authors.forename: Nagahisa
authors.initials: N
authors.lastname: Yoshimura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003930:Diabetic Retinopathy / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D006801:Humans; D008266:Macula Lutea / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity; D055815:Young Adult
keywords: diabetic macular edema; diabetic retinopathy; optical coherence tomography; self-organizing map