Fundus Autofluorescence Imaging of Pigment Epithelial Detachments

Abstract

Abstract: : Purpose: To describe fundus autofluorescence (AF) characteristics of pigment epithelial detachments (PED). Methods: Digital AF images were recorded with a confocal scanning laser ophthalmoscope (Heidelberg Retina Angiograph, exc. 488 nm, em. > 500 nm). Fundus photographs and optical coherence tomography (OCT3, Zeiss) was performed. A total of 35 patients with PEDs were examined. PEDs were associated with age–related macular degeneration (AMD) in 31 patients (mean age 72.4 ± 7.5 years) including lesions with concurrent retinal angiomatous proliferations (RAP) and polypoidal choroidal vasculopathy (PCV), and secondary to idiopathic central serous chorioretinopathy (ICSC) in 4 patients (mean age 51.2 ± 4.6 years). Results: PEDs showed variable characteristics on AF images. While the majority (23 eyes/62.2%) had a corresponding marked evenly distributed increase in AF, in 8 eyes/21.6% there was a decreased AF, and in 6 eyes/16.2% a normal background AF. In the group with elevated AF a higher AF intensity was associated with higher maximal vertical extension of the detached RPE in OCT measurements. However, there were large PEDs with marked prominence in the group with decreased AF signal, all of which had radial hyperpigmented lines overlying the PED. All drusenoid PEDs had an increased AFsignal. Except in 4 eyes (10.8%) with a large area of increased AF surrounding the PED 25 eyes (67.6%) showed a well–defined hypoautofluorescent halo delineating the entire border of the lesion. The width of this halo was smaller in ICSC compared to AMD eyes. The distribution of macular pigment (MP) on AF images was abnormal in all eyes when compared with unaffected fellow eyes. Conclusions: The results indicate that there are heterogenous phenotypic variations in fundus AF associated with PEDs. While AF imaging has been developed as a tool to evaluate RPE lipofuscin, findings here suggest that other dominant fluorophores may occur in the extracellular fluid between RPE and Bruch’s membrane. In contrast to lipofuscin the molecular species in the subRPE fluid remain to be identified. Different AF phenotypes may reflect heterogeneity on a cellular and molecular level, and may thus be relevant for future molecular genetic analyses. Further longitudinal studies using AF imaging may increase our understanding of PEDs in various retinal diseases and may allow us to identify novel prognostic factors.

Keywords: age–related macular degeneration • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • clinical (human) or epidemiologic studies: natural history