title: In vivo identification of morphologic retinal abnormalities in neuromyelitis optica.
abstract: OBJECTIVE
  To assess eyes with neuromyelitis optica (NMO) for morphologic retinal abnormalities utilizing high-definition optical coherence tomography (OCT) imaging.
  
  
  METHODS
  In this cross-sectional study, 39 patients with NMO spectrum disorders and 39 age- and sex-matched healthy controls underwent spectral-domain OCT and visual function testing.
  
  
  RESULTS
  Microcystic macular edema (MME) of the inner nuclear layer (INL) was identified in 10 of 39 patients (26%) and was exclusively found in eyes with a history of optic neuritis (ON). MME eyes had lower high- and low-contrast letter-acuity scores (100%: p = 0.002; 2.5%: p = 0.002; 1.25%: p = 0.004), lower peripapillary retinal nerve fiber layer (RNFL) thickness (p = 0.04), lower macular RNFL thickness (p = 0.004), lower ganglion cell layer + inner plexiform layer (GCIP) thickness (p = 0.007), higher INL thickness (p < 0.001), and a greater number of ON episodes (p = 0.008) relative to non-MME eyes with a history of ON. After adjusting for history of multiple ON episodes, these findings remained significant for macular-RNFL thickness (p = 0.03), INL thickness (p < 0.001), and 100% and 2.5% contrast letter-acuity scores (p = 0.008 and p = 0.03, respectively). NMO spectrum eyes without ON history had lower macular RNFL thickness (p = 0.003), GCIP thickness (p = 0.002), outer nuclear layer thickness (p = 0.02), and low-contrast letter-acuity scores (2.5%: p = 0.03; 1.25%: p = 0.002) compared to healthy controls.
  
  
  CONCLUSIONS
  We have identified a pattern of retinal morphologic abnormalities in NMO that is associated with severe retinal axonal and neuronal loss and corresponding visual disability. MME may contribute to poor visual outcomes following NMO-associated ON or alternatively represent a marker of ON severity. Additionally, our results support that subclinical involvement of the anterior visual pathway may occur in NMO spectrum disorders.
authors.affiliation: From the Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Elias S
authors.initials: ES
authors.lastname: Sotirchos
authors.forename: Shiv
authors.initials: S
authors.lastname: Saidha
authors.forename: Gita
authors.initials: G
authors.lastname: Byraiah
authors.forename: Maureen A
authors.initials: MA
authors.lastname: Mealy
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Ibrahim
authors.forename: Yasir Jamal
authors.initials: YJ
authors.lastname: Sepah
authors.forename: Scott D
authors.initials: SD
authors.lastname: Newsome
authors.forename: John N
authors.initials: JN
authors.lastname: Ratchford
authors.forename: Elliot M
authors.initials: EM
authors.lastname: Frohman
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Balcer
authors.forename: Ciprian M
authors.initials: CM
authors.lastname: Crainiceanu
authors.forename: Quan Dong
authors.initials: QD
authors.lastname: Nguyen
authors.forename: Michael
authors.initials: M
authors.lastname: Levy
authors.forename: Peter A
authors.initials: PA
authors.lastname: Calabresi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D051401:Aquaporin 4 / Q000276:immunology; D001323:Autoantibodies / Q000097:blood; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D008269:Macular Edema / Q000209:etiology; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009471:Neuromyelitis Optica / Q000150:complications / Q000276:immunology / Q000473:pathology*; D012160:Retina / Q000473:pathology*; D041623:Tomography, Optical Coherence; D014787:Vision Tests; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: C496030:AQP4 protein, human; D051401:Aquaporin 4; D001323:Autoantibodies