Abstract
Purpose: :
The aim of this study is to compare autofluorescence (AF) imaging findings to conventional fundus photography and fluorescein angiography (FA) in patients with basal laminar drusen (BLD) using image registration.
Methods: :
Four patients with BLD were studied with AF and conventional imaging. AF imaging employed an excitation filter at 580 nm and a barrier filter at 695 nm with acquisition by a Topcon 50X fundus camera. Corresponding detail regions in each image modality were enlarged for comparison. The AF detail image was registered by a projective transformation in Matlab (Mathworks 7.0, Natick, MA) with the color photograph/red free photograph and/or FA image detail for exact superimposition in Photoshop and lesion comparison.
Results: :
Similar to the "starry sky" pattern in FA, focal hypoautofluorescent lesions significantly outnumbered the drusen identified on color photography and, when the classic FA pattern was present, clearly co–localized with the hyperfluorescent "stars" themselves. Each visible druse in the color or red free photograph corresponded precisely when superimposed to a focal AF lesion. Image registration also revealed subtle depigmentation in the color image for some of the remaining AF lesions.
Conclusions: :
AF imaging appears to be more sensitive than conventional fundus photography and as useful as FA, but less invasive, in diagnosing BLD. Because image registration of all three modalities allows precise lesion comparison for analysis of the disease itself, AF should be considered both a valuable diagnostic and research tool for basal laminar drusen.
Keywords: drusen • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: clinical