title: Reliability and validity of Cirrus and Spectralis optical coherence tomography for detecting retinal atrophy in Alzheimer's disease.
abstract: BACKGROUND
  To evaluate and compare the ability of two Fourier-domain optical coherence tomography (OCT) devices to detect retinal and retinal nerve fibre layer (RNFL) atrophy in patients with Alzheimer's disease (AD) compared with healthy subjects; to test the intra-session reliability of two OCT devices in AD patients and healthy subjects.
  
  
  METHODS
  AD patients (n=75) and age-matched healthy subjects (n=75) underwent three Macular Cube 200 × 200 protocols using the Cirrus and Spectralis OCT devices and three 360° circular scans centred on the optic disc using the Cirrus OCT device, the classic glaucoma application, and the new Nsite Axonal Analytics application of the Spectralis OCT instrument. Differences between healthy and AD eyes were compared, and measurements provided by each OCT protocol were compared. Reliability was measured using intraclass correlation coefficients and coefficients of variation. Correlations between OCT measurements and disease duration and severity were also analysed.
  
  
  RESULTS
  Retinal thinning was observed in AD eyes in all areas except the fovea using both OCT devices. RNFL atrophy was detected in AD eyes with all three protocols, but the Nsite Axonal application was the most sensitive. Measurements by the two OCT devices were correlated, but differed significantly. Reliability was good using all protocols, but better with the glaucoma application of Spectralis. Mean RNFL thickness provided by the Nsite Axonal application correlated with disease duration.
  
  
  CONCLUSIONS
  Fourier-domain OCT is a valid and reliable technique for detecting subclinical RNFL and retinal atrophy in AD, especially using the Nsite Axonal application. RNFL thickness decreased with disease duration.
authors.affiliation: 1] Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain [2] Aragones Institute of Health Sciences, Zaragoza, Spain.
authors.forename: V
authors.initials: V
authors.lastname: Polo
authors.affiliation: 1] Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain [2] Aragones Institute of Health Sciences, Zaragoza, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Garcia-Martin
authors.affiliation: 1] Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain [2] Aragones Institute of Health Sciences, Zaragoza, Spain.
authors.forename: M P
authors.initials: MP
authors.lastname: Bambo
authors.affiliation: 1] Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain [2] Aragones Institute of Health Sciences, Zaragoza, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Pinilla
authors.affiliation: 1] Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain [2] Aragones Institute of Health Sciences, Zaragoza, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Larrosa
authors.affiliation: 1] Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain [2] Aragones Institute of Health Sciences, Zaragoza, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Satue
authors.affiliation: 1] Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain [2] Aragones Institute of Health Sciences, Zaragoza, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Otin
authors.affiliation: 1] Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain [2] Aragones Institute of Health Sciences, Zaragoza, Spain.
authors.forename: L E
authors.initials: LE
authors.lastname: Pablo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis*; D001284:Atrophy; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D009412:Nerve Fibers / Q000473:pathology*; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000295:instrumentation*; D014786:Vision Disorders / Q000175:diagnosis; D014794:Visual Fields