Purpose: 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 by one second time interval immediately after beginning of argon laser excitation. Twenty one eyes of 21 normal subjects were enrolled in the study. To analyze the luminescence of fundus autofluorescence a 80x80 pixels square selection was placed at relatively avascular fundus area of each consecutive image. Individual gray scale values of the selected areas were recorded and time slope was plotted.
Results: Time dependent increment of the autofluorescence was observed in all subjects. Average luminosity value of subjects at the beginning was calculated as 32.5 mean gray value (MGV), and luminosity reached at its maximum (45.4 MGV) between 25-30 seconds.
Conclusion: Excitation time dependent increment in FAF luminosity should to be taken into account while acquiring FAF images for quantitative, comparative and longitudinal studies.