title: Retinal ganglion cell layer thinning within one month of presentation for optic neuritis.
abstract: BACKGROUND
  Spectral domain optical coherence tomography (SD-OCT) reveals retinal ganglion cell layer plus inner plexiform layer (GCL+IPL) and peripapillary retinal nerve fiber layer (pRNFL) thinning in chronic optic nerve injury. At presentation, swelling of the pRNFL confounds evaluation of early axon loss.
  
  
  OBJECTIVE
  We studied whether the GCL+IPL thins before the pRNFL, the trajectory of GCL+IPL loss and relationship to vision.
  
  
  METHODS
  We prospectively evaluated 33 eyes (study) with new optic neuritis, using perimetry and SD-OCT with investigative three-dimensional layer segmentation and commercial two-dimensional segmentation to compute the GCL+IPL and pRNFL thickness.
  
  
  RESULTS
  At presentation, GCL+IPL thickness (82.4±8.8 µm) did not differ from unaffected fellow eyes (81.2±6.7 µm), via the three-dimensional method, while the two-dimensional method failed in 9% of study eyes. At 1-2 months, there was thinning of the pRNFL in 10% and of the GCL+IPL in 93% of study eyes. GCL+IPL reduction was greatest during the first 2 months. GCL+IPL thinning at 1-2 months correlated with GCL+IPL thinning at 6 months (r=0.84, P=0.01) and presentation visual acuity (r=0.48, P=0.006) and perimetric mean deviation (r=0.52, P=0.003).
  
  
  CONCLUSIONS
  GGL+IPL is an early biomarker of structural injury in optic neuritis as thinning develops within 1-2 months of onset, prior to pRNFL thinning.
authors.affiliation: New York Eye and Ear Infirmary, Mount Sinai Roosevelt Hospital, New York, USA mkuper@chpnet.org.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Kupersmith
authors.affiliation: Department of Electrical and Computer Engineering, University of Iowa, Iowa, USA/Department of Ophthalmology, Iowa University School of Medicine and Center for Prevention and Treatment of Visual Loss, Iowa, USA.
authors.forename: Mona K
authors.initials: MK
authors.lastname: Garvin
authors.affiliation: Department of Electrical and Computer Engineering, University of Iowa, Iowa, USA.
authors.forename: Jui-Kai
authors.initials: JK
authors.lastname: Wang
authors.affiliation: Carl Zeiss-Meditec, Inc., Dublin, CA.
authors.forename: Mary
authors.initials: M
authors.lastname: Durbin
authors.affiliation: Department of Ophthalmology, Iowa University School of Medicine and Center for Prevention and Treatment of Visual Loss, Iowa, USA.
authors.forename: Randy
authors.initials: R
authors.lastname: Kardon
mesh_terms: D000328:Adult; D006801:Humans; D009902:Optic Neuritis / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D011446:Prospective Studies; D012160:Retina / Q000473:pathology*; D012165:Retinal Ganglion Cells / Q000473:pathology*; D013997:Time Factors; D041623:Tomography, Optical Coherence / Q000379:methods; D014792:Visual Acuity
keywords: OCT; RNFL; Retinal ganglion cell layer; optic neuritis; peripapillary retinal nerve fiber layer