title: Excitation-time-dependent increment in the luminescence of fundus autofluorescence.
abstract: OBJECTIVE
  To investigate the excitation-time-dependent increment in luminescence of fundus autofluorescence.
  
  
  METHODS
  Fundus autofluorescence (FAF) images were obtained with a confocal scanning laser ophthalmoscope. Consecutive 60 images of each eye were taken at 1 s time intervals immediately after the beginning of argon laser excitation. Twenty-one eyes of 21 normal subjects were enrolled in the study. To analyse the luminescence of fundus autofluorescence, an 80 x 80 pixel square selection was placed in a relatively avascular fundus area of each consecutive image. Individual grey-scale values of the selected areas were recorded, and the time slope was plotted.
  
  
  RESULTS
  The time-dependent increment of the autofluorescence was observed in all subjects. The average luminosity value of subjects at the beginning was calculated as 32.5 mean grey value (MGV), and luminosity reached its maximum (45.4 MGV) between 25 and 30 s.
  
  
  CONCLUSIONS
  The excitation-time-dependent increment in FAF luminosity should be taken into account while acquiring FAF images for quantitative, comparative and longitudinal studies.
authors.affiliation: Department of Ophthalmology, GATA Haydarpasa Training Hospital, Istanbul, Turkey. ali_ayata@yahoo.com
authors.forename: A
authors.initials: A
authors.lastname: Ayata
authors.forename: S
authors.initials: S
authors.lastname: Tatlipinar
authors.forename: M
authors.initials: M
authors.lastname: Unal
authors.forename: D
authors.initials: D
authors.lastname: Ersanli
authors.forename: A H
authors.initials: AH
authors.lastname: Bilge
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D005260:Female; D005451:Fluorescein Angiography / Q000379:methods; D006801:Humans; D049449:Luminescence; D008297:Male; D019721:Ophthalmoscopes; D009887:Ophthalmoscopy / Q000379:methods*; D012164:Retinal Diseases / Q000175:diagnosis*; D013997:Time Factors