title: Quantitative fundus autofluorescence in healthy eyes.
abstract: OBJECTIVE
  Fundus autofluorescence was quantified (qAF) in subjects with healthy retinae using a standardized approach. The objective was to establish normative data and identify factors that influence the accumulation of RPE lipofuscin and/or modulate the observed AF signal in fundus images.
  
  
  METHODS
  AF images were acquired from 277 healthy subjects (age range: 5-60 years) by employing a Spectralis confocal scanning laser ophthalmoscope (cSLO; 488-nm excitation; 30°) equipped with an internal fluorescent reference. For each image, mean gray level was calculated as the average of eight preset regions, and was calibrated to the reference, zero-laser light, magnification, and optical media density from normative data on lens transmission spectra. Relationships between qAF and age, sex, race/ethnicity, eye color, refraction/axial length, and smoking status were evaluated as was measurement repeatability and the qAF spatial distribution.
  
  
  RESULTS
  qAF levels exhibited a significant increase with age. qAF increased with increasing eccentricity up to 10° to 15° from the fovea and was highest superotemporally. qAF values were significantly greater in females, and, compared with Hispanics, qAF was significantly higher in whites and lower in blacks and Asians. No associations with axial length and smoking were observed. For two operators, between-session repeatability was ± 9% and ± 12%. Agreement between the operators was ± 13%.
  
  
  CONCLUSIONS
  Normative qAF data are a reference tool essential to the interpretation of qAF measurements in ocular disease.
authors.affiliation: Department of Ophthalmology, Harkness Eye Institute, Columbia University, New York, New York, USA.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Greenberg
authors.forename: Tobias
authors.initials: T
authors.lastname: Duncker
authors.forename: Russell L
authors.initials: RL
authors.lastname: Woods
authors.forename: R Theodore
authors.initials: RT
authors.lastname: Smith
authors.forename: Janet R
authors.initials: JR
authors.lastname: Sparrow
authors.forename: François C
authors.initials: FC
authors.lastname: Delori
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D005654:Fundus Oculi; D006801:Humans; D008062:Lipofuscin / Q000378:metabolism; D008297:Male; D008543:Melanins / Q000378:metabolism; D008875:Middle Aged; D019721:Ophthalmoscopes; D009887:Ophthalmoscopy / Q000379:methods* / Q000592:standards*; D061848:Optical Imaging / Q000295:instrumentation / Q000379:methods* / Q000592:standards*; D044469:Racial Groups; D012016:Reference Values; D012160:Retina / Q000166:cytology / Q000378:metabolism*; D055213:Retinal Pigment Epithelium / Q000166:cytology / Q000378:metabolism*; D055815:Young Adult
chemical_list: D008062:Lipofuscin; D008543:Melanins
keywords: lipofuscin; melanin; quantitative fundus autofluorescence; retina; retinal pigment epithelium; scanning laser ophthalmoscope