Fundus autofluorescence patterns of drusen in age-related macular degeneration

Abstract

To investigate the characteristics of fundus autofluorescence (FAF) patterns of drusen in patients with nonexudative age-related macular degeneration (AMD). It was a retrospective case series study. Spatial distribution and intensity of FAF of 63 cases (78 eyes) with nonexudative AMD were recorded using a confocal scanning laser ophthalmoscopy (cSLO, Heidelberg Retina Angiograph 2, HRA2, Heidelberg, Germany), the excitation light used was at 488 nm (argon laser), emission light at 514 nm (barrier filter), and fundus field-of-view at 30-degrees. Color fundus photographs were obtained with Kowa Nonmyd 7. Three-dimensional fundus images were captured by spectral domain optical coherence tomography (Topcon, 3D OCT-1000, Japan). The FAF changes did not correlate topographically with visible fundus changes and 3D-OCT images in 78 eyes with drusen in nonexudative AMD. The majority of these eyes (68 out of 78) showed abnormal FAF signal of drusen at the posterior pole, which could be classified into seven different patterns according to their different features: minimal, focal confluent, linear, patchy, lace-like, speckled and scattered changes. In the remaining 10 eyes, the small lesions presented in color fundus photos were not detected in FAF examination. Therefore, a homogeneous background signal similar to the normal fundus was obtained by FAF examination. In addition, 15 patients exhibited abnormal autofluorescence in both eyes, 13 of them showed asymmetrical FAF changes, indicating that asymmetrical lesions might be presented. Various patterns of abnormal FAF can be clearly imaged with HRA2-cSLO in nonexudative AMD, reflecting different stages of this disease. Periodic observation of drusen with FAF examination is of great clinical value in the estimation of occurrence and development of AMD.