title: En Face Optical Coherence Tomography to Detect and Measure Geographic Atrophy.
abstract: OBJECTIVE
  To detect and quantify geographic atrophy (GA) secondary to age-related macular degeneration using en face optical coherence tomography (OCT) and to correlate it to GA measured with fundus autofluorescence (FAF).
  
  
  METHODS
  Twenty-four consecutive patients (27 eyes) were studied with both standard (STD)- and enhanced depth imaging (EDI)-OCT. En face OCT images were obtained at the outer retinal layer (OR) and at the choroidal layer (CH) level for both STD- and EDI-OCT. Areas of GA were measured on the en face OCT images and were correlated with the GA areas measured on blue (B)- and near infrared (NIR)-wavelength FAF images.
  
  
  RESULTS
  The intraoperator agreement in GA measurement was excellent with en face OCT at both OR and CH levels (intraclass correlation coefficient [ICC] = 0.99 in EDI and 0.98 in STD at OR level; 0.99 in EDI and 0.99 in STD at CH level). The interoperator agreement was excellent at OR level (ICC = 0.97 in EDI and 0.98 in STD), good at CH level (ICC = 0.95 in EDI, 0.90 in STD). The geographic atrophy area, at both B-FAF and NIR-FAF, was significantly equivalent to the GA area at OR level (B-FAF versus SDT-OR and EDI-OR: P = 0.0057 and 0.0090, respectively; NIR-FAF versus STD-OR and EDI-OR: P = 0.0131 and 0.0036, respectively), but not at CH level.
  
  
  CONCLUSIONS
  En face OCT is a reliable method to detect and quantify GA, particularly when analyzed at the OR level, where the photoreceptors' loss creates an abrupt transition in OCT reflectivity.
authors.affiliation: Institute of Ophthalmology, University of Padova, Padova, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Pilotto
authors.affiliation: Institute of Ophthalmology, University of Padova, Padova, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Guidolin
authors.affiliation: Institute of Ophthalmology, University of Padova, Padova, Italy.
authors.forename: Enrica
authors.initials: E
authors.lastname: Convento
authors.affiliation: Institute of Ophthalmology, University of Padova, Padova, Italy.
authors.forename: Rachele
authors.initials: R
authors.lastname: Antonini
authors.affiliation: Institute of Ophthalmology, University of Padova, Padova, Italy.
authors.forename: Francesco Giuseppe
authors.initials: FG
authors.lastname: Stefanon
authors.affiliation: G.B. Bietti Foundation, IRCCS, Roma, Italy.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Parrozzani
authors.affiliation: Institute of Ophthalmology, University of Padova, Padova, Italy 2G.B. Bietti Foundation, IRCCS, Roma, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Midena
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002829:Choroid / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D057092:Geographic Atrophy / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D008268:Macular Degeneration / Q000150:complications / Q000175:diagnosis; D008297:Male; D012372:ROC Curve; D015203:Reproducibility of Results; D012160:Retina / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000379:methods*