Abstract
Abstract: :
Purpose: To evaluate a new method for characterization of the spatial distribution of fundus autofluorescence in the normal fundus. Methods: A modified confocal scanning laser ophthalmoscope (HRA, Heidelberg Engineering, Dossenheim, Germany) was optimized for fundus autofluorescence imaging at excitation wavelengths of 488 and 514 nm and a barrier filter at 530 nm. The spatial distributions of optical density and the amount of autofluorescence caused by the fluorophores were computed from the autofluorescence images obtained at the two different wavelengths. The distributions were displayed graphically. Furthermore, the radial distributions of optical density and the autofluorescence distribution around the fovea were evaluated. The study included a total of 50 subjects aged from 18 to 79 years. Inclusion criteria were visual acuity of 20/30 or better, clear optical media and no concomitant eye disease. Among the subjects were 30 patients with age related maculopathy (ARM) and 20 healthy controls. All patients with ARM had large soft drusen and pigmentary abnormalities. Results: The autofluorescence distribution in healthy subjects showed an increase of autofluorescence intensity from the center of the fovea towards the periphery. In most cases a plateau of autofluorescence intensity was reached at 4 degree excentricity. In patients with age–related maculopathy the global autofluorescence distribution was similar to that in healthy subjects. However, areas covered by drusen were associated with different AF pattern. Large soft drusen showed increased autofluorescence in most cases (25/30 eyes). Smaller drusen showed a central low AF with a surrounding area of increased AF. Conclusions: Imaging of fundus AF distribution is a new method to assess the lipofuscin distribution in a clinical setting. Similar to previous studies (Delori et al) we were able to demonstrate altered autofluorescence in areas covered by drusen.
Keywords: age-related macular degeneration • macular pigment • imaging/image analysis: clinical