title: Reference Clinical Database for Fixation Stability Metrics in Normal Subjects Measured with the MAIA Microperimeter.
abstract: OBJECTIVE
  The purpose of this study was to establish a normal reference database for fixation stability measured with the bivariate contour ellipse area (BCEA) in the Macular Integrity Assessment (MAIA) microperimeter.
  
  
  METHODS
  Subjects were 358 healthy volunteers who had the MAIA examination. Fixation stability was assessed using two BCEA fixation indices (63% and 95% proportional values) and the percentage of fixation points within 1° and 2° from the fovea (P1 and P2). Statistical analysis was performed with linear regression and Pearson's product moment correlation coefficient.
  
  
  RESULTS
  Average areas of 0.80 deg2(min = 0.03, max = 3.90, SD = 0.68) for the index BCEA@63% and 2.40 deg2(min = 0.20, max = 11.70, SD = 2.04) for the index BCEA@95% were found. The average values of P1 and P2 were 95% (min = 76, max = 100, SD = 5.31) and 99% (min = 91, max = 100, SD = 1.42), respectively. The Pearson's product moment test showed an almost perfect correlation index,r= 0.999, between BCEA@63% and BCEA@95%. Index P1 showed a very strong correlation with BCEA@63%,r= -0.924, as well as with BCEA@95%,r= -0.925. Index P2 demonstrated a slightly lower correlation with both BCEA@63% and BCEA@95%,r= -0.874 and -0.875, respectively.
  
  
  CONCLUSIONS
  The single parameter of the BCEA@95% may be taken as accurately reporting fixation stability and serves as a reference database of normal subjects with a cutoff area of 2.40 ± 2.04 deg2in MAIA microperimeter.
  
  
  CONCLUSIONS
  Fixation stability can be measured with different indices. This study originates reference fixation values for the MAIA using a single fixation index.
authors.affiliation: Division of Clinical Neurosciences, University of Nottingham, Queen's Medical Centre, Nottingham, UK.
authors.forename: Marco U
authors.initials: MU
authors.lastname: Morales
authors.affiliation: Division of Clinical Neurosciences, University of Nottingham, Queen's Medical Centre, Nottingham, UK.
authors.forename: Saker
authors.initials: S
authors.lastname: Saker
authors.affiliation: Division of Clinical Neurosciences, University of Nottingham, Queen's Medical Centre, Nottingham, UK.
authors.forename: Craig
authors.initials: C
authors.lastname: Wilde
authors.affiliation: Centervue, Padua, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Pellizzari
authors.affiliation: Institute of Vision and Optics, Department of Medicine, University of Crete, Heraklion, Greece.
authors.forename: Aristophanes
authors.initials: A
authors.lastname: Pallikaris
authors.affiliation: CLEVER Eye Institute, Slidell, LA, USA.
authors.forename: Neil
authors.initials: N
authors.lastname: Notaroberto
authors.affiliation: Division of Clinical Neurosciences, University of Nottingham, Queen's Medical Centre, Nottingham, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: Rubinstein
authors.affiliation: Centervue, Padua, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Rui
authors.affiliation: Centro Studi Ipovisione, Milan, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Limoli
authors.affiliation: Vision Protection & Performance Division, USAARL, Fort Rucker, AL, USA.
authors.forename: Michael K
authors.initials: MK
authors.lastname: Smolek
authors.affiliation: Division of Clinical Neurosciences, University of Nottingham, Queen's Medical Centre, Nottingham, UK.
authors.forename: Winfried M
authors.initials: WM
authors.lastname: Amoaku
keywords: BCEA; fixation; microperimetry; normal