title: Microcystic inner nuclear layer abnormalities and neuromyelitis optica.
abstract: OBJECTIVE
  Microcystic abnormalities involving the inner nuclear layer of the retina occurs in a subset of patients with multiple sclerosis, most commonly in eyes previously affected by symptomatic optic neuritis. Acute optic neuritis is a cardinal manifestation of neuromyelitis optica (NMO). To our knowledge, microcystic inner nuclear layer abnormalities have not been investigated in NMO.
  
  
  OBJECTIVE
  To establish whether microcystic inner nuclear layer abnormalities occur in NMO.
  
  
  METHODS
  Observational, retrospective study.
  
  
  METHODS
  University of California at San Francisco Multiple Sclerosis Center (academic specialty clinic).
  
  
  METHODS
  Twenty-five consecutive patients with NMO based on 2006 diagnostic criteria or with NMO spectrum disease (defined by seropositivity for anti-aquaporin 4 IgG in the context of a single episode of transverse myelitis or optic neuritis).
  
  
  METHODS
  Spectral-domain optical coherence tomography.
  
  
  METHODS
  Identification of microcystic inner nuclear layer pathology on spectral-domain optical coherence tomography. Multivariable linear regression was used to examine associations between microcystic changes and measures of retinal structure and function. The hypothesis was generated prior to the data being reviewed and analyzed.
  
  
  RESULTS
  Microcystic changes were identified in 5 of 25 patients with NMO (20%) and 7 of 48 total eyes, including 7 of 29 eyes (24%) previously affected by optic neuritis. Microcystic changes occurred exclusively in eyes with a history of acute symptomatic optic neuritis (100% of eyes with microcystic changes had experienced prior optic neuritis compared with 71% of NMO eyes without microcystic abnormalities). There were no significant differences between patients with NMO with and without microcystic changes in terms of age, sex, and aquaporin 4-IgG antibody status. The mean age in this cohort was 44 years (range, 13-81 years); 84% were women; 80% were aquaporin 4-IgG seropositive; and the median Expanded Disability Status Scale score was 4.0 (interquartile range, 3.0-6.5).
  
  
  CONCLUSIONS
  Microcystic inner nuclear layer pathology occurs in a proportion of patients with NMO in eyes previously affected by acute optic neuritis. Additional research is needed to understand the cause of this retinal pathology and determine whether it contributes to persistent visual disability in patients with NMO following optic neuritis.
authors.affiliation: Multiple Sclerosis Center, Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA. jeffrey.gelfand@ucsf.edu
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Gelfand
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Cree
authors.forename: Rachel
authors.initials: R
authors.lastname: Nolan
authors.forename: Sam
authors.initials: S
authors.lastname: Arnow
authors.forename: Ari J
authors.initials: AJ
authors.lastname: Green
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009471:Neuromyelitis Optica / Q000175:diagnosis / Q000473:pathology*; D009902:Optic Neuritis / Q000473:pathology*; D012160:Retina / Q000166:cytology / Q000473:pathology*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence / Q000295:instrumentation / Q000379:methods*; D014787:Vision Tests; D055815:Young Adult