title: Retinal Morphology and Sensitivity Are Primarily Impaired in Eyes with Neuromyelitis Optica Spectrum Disorder (NMOSD).
abstract: BACKGROUND
  Previous studies of neuromyelitis optica spectrum disorder (NMOSD) using spectral domain optical coherence tomography (SD-OCT) showed that the outer nuclear layer (ONL) in eyes without a history of optic neuritis (ON) was thinner than that of healthy controls. It remains unclear whether the ONL thinning is caused by a direct attack on the retina by an autoantibody or a retrograde degeneration.
  
  
  OBJECTIVE
  To determine the mechanisms involved in the retinal damage in eyes with NMOSD without ON.
  
  
  METHODS
  SD-OCT was used to determine the thicknesses of the different retinal layers of 21 eyes of 12 NMOSD patients without prior ON and 19 eyes of 10 healthy controls. Eyes with peripapillary retinal nerve fiber layer (RNFL) thinning were excluded to eliminate the confounding effects of retrograde degeneration. Microperimetry was used to determine the central retinal sensitivity. The data of the two groups were compared using generalized estimated equation models to account for inter-eye dependencies.
  
  
  RESULTS
  The ganglion cell plus inner plexiform layer and the inner nuclear layer plus outer plexiform layer thicknesses of the NMOSD eyes were not significantly different from that of the control eyes (P = 0.28, P = 0.78). However, the ONL and average macular thickness (AMT) in the NMOSD eyes were significantly thinner than that of the control eyes (P = 0.022, P = 0.036). The retinal sensitivity in the central 10°, 10° to 2°, and 2° sectors were significantly lower in the NMOSD eyes than in the control eyes (P = 0.013, P = 0.022, P = 0.002).
  
  
  CONCLUSIONS
  The ONL thinning, AMT thinning, and reduced retinal sensitivity in eyes with NMOSD without significant peripapillary RNFL thinning are most likely due to direct retinal pathology.
authors.affiliation: Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Chiba, Chiba, Japan.
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Akiba
authors.affiliation: Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Chiba, Chiba, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Yokouchi
authors.affiliation: Department of Neurology, Chiba University Graduate School of Medicine, Chiba, Chiba, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Mori
authors.affiliation: Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Chiba, Chiba, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Oshitari
authors.affiliation: Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Chiba, Chiba, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Baba
authors.affiliation: Department of Neurology, Chiba University Graduate School of Medicine, Chiba, Chiba, Japan.
authors.forename: Setsu
authors.initials: S
authors.lastname: Sawai
authors.affiliation: Department of Neurology, Chiba University Graduate School of Medicine, Chiba, Chiba, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kuwabara
authors.affiliation: Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Chiba, Chiba, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Yamamoto
mesh_terms: D000328:Adult; D000368:Aged; D005123:Eye / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D015999:Multivariate Analysis; D009412:Nerve Fibers / Q000473:pathology; D009471:Neuromyelitis Optica / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012160:Retina / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D012165:Retinal Ganglion Cells / Q000473:pathology; D041623:Tomography, Optical Coherence / Q000379:methods; D014792:Visual Acuity