title: Tracking changes over time in retinal nerve fiber layer and ganglion cell-inner plexiform layer thickness in multiple sclerosis.
abstract: BACKGROUND
  Neurodegeneration plays an important role in permanent disability in multiple sclerosis (MS).
  
  
  OBJECTIVE
  The objective of this paper is to determine whether progressive neurodegeneration occurs in MS eyes without clinically evident inflammation.
  
  
  METHODS
  Retinal nerve fiver layer thickness (RNFLT) and ganglion cell-inner plexiform layer thickness (GCIPT) were measured using Cirrus optical coherence tomography (OCT) in 133 relapsing-remitting MS (RRMS) patients (149 non-optic neuritis (ON), 97 ON eyes, last ON ≥6 months). Ninety-three patients were scanned at two visits. Percentages of abnormal GCIPT vs RNFLT (<5% of machine norms) in cross-sectional data were compared. Relations between RNFLT/GCIPT and MS duration (cross-sectional) and follow-up time (longitudinal) were assessed.
  
  
  RESULTS
  GCIPT was abnormal in more eyes than RNFLT (27% vs 16% p = 0.004 in non-ON, 82% vs 72% p = 0.007 in ON). RNFLT and GCIPT decreased with MS duration by -0.49 µm/yr (p = 0.0001) and -0.36 (p = 0.005) for non-ON; -0.52 (p = 0.003) and -0.41 (p = 0.007) for ON. RNFLT and GCIPT decreased with follow-up time by -1.49 µm/yr (p < 0.0001) and -0.53 (p = 0.004) for non-ON, -1.27 (p = 0.002) and -0.49 (p = 0.04) for ON.
  
  
  CONCLUSIONS
  In RRMS eyes without clinically evident inflammation, progressive loss of RNFLT and GCIPT occurred, supporting the need for neuroprotection in addition to suppression of autoimmune responses and inflammation.
authors.affiliation: College of Optometry, Houston, USA.
authors.forename: Divya
authors.initials: D
authors.lastname: Narayanan
authors.affiliation: College of Optometry, Houston, USA hcheng@optometry.uh.edu.
authors.forename: Han
authors.initials: H
authors.lastname: Cheng
authors.affiliation: College of Optometry, Houston, USA.
authors.forename: Karlie N
authors.initials: KN
authors.lastname: Bonem
authors.affiliation: College of Optometry, Houston, USA.
authors.forename: Roberto
authors.initials: R
authors.lastname: Saenz
authors.affiliation: MS Eye CARE Clinic, University of Houston, USA.
authors.forename: Rosa A
authors.initials: RA
authors.lastname: Tang
authors.affiliation: College of Optometry, Houston, USA.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Frishman
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000175:diagnosis* / Q000473:pathology; D009410:Nerve Degeneration; D009902:Optic Neuritis / Q000175:diagnosis* / Q000473:pathology; D011379:Prognosis; D012165:Retinal Ganglion Cells / Q000473:pathology*; D055351:Retinal Neurons / Q000473:pathology*; D013997:Time Factors; D041623:Tomography, Optical Coherence; D055815:Young Adult
keywords: Multiple sclerosis; ganglion cell inner plexiform layer; neurodegeneration; optic neuritis; optical coherence tomography; retinal nerve fiber layer