Abstract
Abstract: :
Purpose:Prognosis and treatment benefit in exsudative age–related macular degeneration (AMD) is largely dependent on lesion composition, size and stage. This study has the aim to evaluate the advantages and disadvantages of the current imaging modalities and to identify features characteristic for the different subgroups of chorioretinal disease. Methods:55 eyes of 55 patients demonstrating active chorioretinal disease were included: occult (occCNV) and classic neovascularization(classCNV) as well as patients with serous pigment epithelial detachment (sPED). Three–dimensional topographic angiography (TAG), retinal thickness analyzis (RTA), optical coherence tomography (OCT) and fluorescein angiography (FA) were used for imaging, documented features were correlated. Results:In occCNV FA showed stippled hyperfluorescence in early and a diffuse leakage in late phase. The CNV complex was precisely delineated by TAG, while RTA and OCT maps failed to detect the lesion. A PED–like prominence and pathologic alterations of the retinal pigment epithelium/choriocappillary band (RPE/CC band) could be seen in single scan OCT. ClassCNV are typically described by a well defined hyperfluorescence pattern in early and late phase FA. The neovascular membrane was delineated threedimensionally in TAG. OCT and RTA maps usually showed an increase in retinal thickness but did not isolate the CNV membrane. Single scan OCT showed retinal edema, typical fibrotic alterations in the RPE and intraretinal cysts. Duplicatures of the RPE/CC band were also seen. In sPED hypofluorescence in the early and a hyperfluorescence in the late phase was found in FA. TAG demonstrates a well–defined fluid pooling and the dynamic of fluid accumulation over time. RTA and OCT maps detected the margins of the lesion only, whereas single scan OCT showed a RPE bubble with serous detachment of the sensory retina at the borders of the sPED. Conclusions:Three–dimensional imaging methods add relevant diagnostic information in a specific combination of features, often complementing each other. All modalities together allow an early detection and differentiation of chorioretinal disease. However, features have to be interpreted with caution when using computer aided techniques because algorithm based artifacts should be recognized.
Keywords: age–related macular degeneration • choroid: neovascularization • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)