En Face OCT And Fibrovascular Pigment Epithelium Detachement In AMD

Purpose:Spectral Domain Optical Coherence Tomography (SD-OCT) is an imaging technique that has become one of the reference method of examinations for the diagnosis and follow-up of patients with wet age-related macular degeneration (AMD).The purpose of this study was to obtain segmentation of SD-OCT according to a frontal scan technique in EDI mode and to analyse neovascularization in fibro-vascular pigment epithelial detachment (PED) in AMD by "en face" SD-OCT.

Methods:Series of 29 patients with subfoveal fibrovascular pigment epithelial detachment (FV-PED) in age-related macular degeneration.Fluorescein angiography, indocyanine green angiography and spectral domain optical coherence tomography (SD-OCT; Spectralis, Heidelberg, Germany) images were analysed.Volume acquisition of 97 EDI sections at 30 µm intervals was obtained, with a summation of 9 images for each retrofoveal scan.The image was superimposed on infrared and SLO ICG images to confirm the neovascularization.

Results:The hyper-reflective course of choroidal neovascularization was visualized within the hyporeflective fibrovascular pigment epithelial detachment by "en face" optical coherence tomography (24/29 cases). In 22 cases, the fluid accumulation was visible behind the choroidal newvessels and the normal choroid vessels became visible ,more deeper only . The pattern of CNV was correlated and confirmed on SLO-ICG pictures for all cases.The 5 other cases presented with associated predominant fibrosis inducing homogenous moderate hyper reflectivity that hidden the neovascular network.

Conclusions:Conventional Spectral Domain Optical Coherence Tomography only provides antero-posterior sections that mainly visualize the exudative reaction of the neovascular network.This new "en face" Spectral Domain Optical Coherence Tomography method of imaging allows analysis of not only the contours and the shape of the detachment but also, and most importantly, visualizes the choroidal neovascular network in fibro-vascular PED.This imaging is obtained by means of an "en face" frontal mode with dynamic analysis, section by section, on standard OCT or SLO-ICG images with point-by-point correspondence.Dynamic segmentation of the macula by "En face" SD OCT allows direct visualisation of choroidal neovascularization within a pigment epithelial detachment and their localization, without dye injection .