title: High-Resolution Spectral Domain-Optical Coherence Tomography in Multiple Sclerosis, Part II - the Total Macular Volume. The First Follow-Up Study over 2 Years.
abstract: BACKGROUND
  Recent studies investigating the use of optical coherence tomography (OCT) in multiple sclerosis (MS) patients have resulted in wide-ranging and often contradictory outcomes. This is mainly due to the complex etiology and heterogeneity of MS, physiological variations in the retinal nerve fiber layer (RNFL) and/or total macular volume (TMV), and limitations in methodology. It remains to be discovered whether any retinal changes in MS develop continuously or in a stepwise fashion, and whether these changes occur in all or a subset of patients. High-resolution spectral domain-OCT devices (SD-OCT) would be required to detect subtle retinal changes and longitudinal studies would have to be carried out to investigate retinal changes over time. In addition, if the hypothesis is correct, then retinal and global brain tissue changes should be detected in a substantial majority of MS patients and detection should be possible with a high degree of disease activity and/or long disease course.
  
  
  METHODS
  In order to address the factors above, 37 MS patients (relapsing-remitting, n = 27; secondary progressive, n = 10) were examined prospectively on two occasions with a median interval of 22.4 ± 0.5 months [range 19-27]. SD-OCT was utilized with the Spectralis 3.5 mm circle scan protocol (with locked reference images and eye-tracking mode). None of the patients had optic neuritis 12 months prior to study entry or during the observation period.
  
  
  RESULTS
  The initial TMV pattern differed between study participants, but remained relatively unchanged over the 2-year observation period despite high disease activity or long disease course. The TMV correlated well with the RNFL.
  
  
  CONCLUSIONS
  The significance of differences in TMV (and RNFL) between study participants remains unclear. Until these differences have been explored further, OCT data in MS patients should be interpreted with caution.
authors.affiliation: Department of Ophthalmology, Medical University of Vienna , Vienna , Austria ; Department of Ophthalmology, Faculty of Medicine Mannheim, University of Heidelberg , Mannheim , Germany.
authors.forename: Nermin
authors.initials: N
authors.lastname: Serbecic
authors.affiliation: Department of Neurology, SMZ-Ost Donauspital , Vienna , Austria.
authors.forename: Fahmy
authors.initials: F
authors.lastname: Aboul-Enein
authors.affiliation: Department of Ophthalmology, Faculty of Medicine Mannheim, University of Heidelberg , Mannheim , Germany.
authors.forename: Sven C
authors.initials: SC
authors.lastname: Beutelspacher
authors.affiliation: Nuffield Department of Surgical Sciences, Division of Medical Sciences, University of Oxford , Oxford , UK.
authors.forename: Adnan
authors.initials: A
authors.lastname: Khan
authors.affiliation: Department of Ophthalmology, Medical University of Vienna , Vienna , Austria.
authors.forename: Clemens
authors.initials: C
authors.lastname: Vass
authors.affiliation: Department of Neurology, SMZ-Ost Donauspital , Vienna , Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kristoferitsch
authors.affiliation: Department of Ophthalmology, Medical University of Vienna , Vienna , Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Reitner
authors.affiliation: Department of Ophthalmology, Medical University of Vienna , Vienna , Austria.
authors.forename: Ursula
authors.initials: U
authors.lastname: Schmidt-Erfurth
keywords: MRI; MS; OCT; macula lutea; neurodegenerative diseases