Session Title: Imaging IV
Session Date/Time: Sunday 20/09/2015 | 11:00-13:00
Paper Time: 11:00
First Author: : S.Guigou FRANCE
Co Author(s): : S. Soare M. Chardavoine C. Marc C. Boulicot
PURPOSE:To characterize with SD -OCT the appearance of retinal ischemia due to different etiologies for quick, reliable and non – invasive diagnosis.
With the development of next generation retinal imaging, such as Spectral Domain Optical Coherence Tomography (SD -OCT), the analysis of the retinal ischemia is increasingly detailed . We can thus identify the affected retinal layer and extent of ischemia.
Retrospective observational case series reviewing clinical and imaging data from seven patients with retinal multimodal analysis (color photographs, SD-OCT and fluorescein angiography HRA / Spectralis Heidelberg). The analyzed pathologies are: retinal artery occlusions (RAO) embolic or traumatic origin, paracentral acute middle maculopathy (PAMM), acute macular neuroretinopathy (AMN), retinal vein occlusion (RVO) with patchy retinal whitening.
The 7 patients had a decreased visual acuity due to retinal ischemia whose appearance in SD-OCT was typical: hyperreflectivity of the affected retinal layer during the acute phase followed by atrophy of the same layer in long-term. The RAO is characterized by hyperreflective lesion followed by atrophy of the ganglion cell layer (GCL) and the inner plexiform layer (IPL) in the occlused arterial territory, equivalent to the ischemic territory identified by fluorescein angiography (FA). RVO with patchy retinal whitening manifests at the acute phase by segmental hyperrefletivity of the IPL and the inner nuclear layer (INL) followed by atrophy of the same layers. FA in patchy retinal whitening corresponds to hypoperfusion of venular network (image that matches perfectly the OCT en face). The PAMM appears as a segmental hyperreflectivity of INL and outer plexiform layer (OPL), due to the ischemia of the intermediate capillary plexus with normal FA. It also progresses to atrophy. In NMA hyperreflectitity followed by segmental atrophy of the OPL and the outer nuclear layer (ONL) is due to ischemia of the deep capillary plexus, normal FA.
The SD-OCT is an excellent diagnostic and monitoring tool of retinal diseases in general and ischemic diseases in particular. Thus, the diagnosis of RAO and RVO with patchy retinal whitening is quickly achieved without using the FA. It increased the diagnostic sensitivity of AMN, especially in cases with normal fundus. The detailed analysis with en face OCT and customized segmentation of the retinal layers allows the description of a new pathological entity, the PAMM. In most cases OCT-SD with volumetric acquisition of the macula only permits a rapid, accurate and non-invasive etiologic diagnosis.