Impact of Choriocapillaris Flow on Multifocal Electroretinography in Intermediate Age-Related Macular Degeneration Eyes

Abstract

In intermediate age-related macular degeneration eyes, PNPCA and average signal void size are related to N1 multifocal electroretinogram implicit times, which suggests an association between CC perfusion and photoreceptor function.

Quantitative choriocapillaris evaluation in intermediate age‐related macular degeneration by swept‐source optical coherence tomography angiography

“…Moreover, a higher average CC signal void size was reported in eyes with early and iAMD and type 3 neovascularization in the fellow eye versus early and iAMD and type 1 or 2 neovascularization in the fellow eye (Borrelli et al. ,b,c). It is clearly established that patients with nAMD in one eye have a higher risk of developing nAMD in the fellow eye, therefore, these data may support the hypothesis that CC impairment could drive the development of neovascular form of AMD.…”

“…Borrelli et al. () used SS‐OCT‐A to evaluate eyes with iAMD and found a significant CC flow impairment (increased signal void area compared to healthy controls) that topographically corresponded to the area covered by drusen.…”

Early Retinal Flow Changes after Vitreoretinal Surgery in Idiopathic Epiretinal Membrane Using Swept Source Optical Coherence Tomography Angiography

“…To date, optical coherence tomography angiography (OCTA) has been introduced in ERM evaluation, allowing a detailed assessment of retinal vascular plexuses and highlighting structural and functional changes related to ERM presence preoperatively and modifications of retinal flow after its removal [10][11][12][13][14].…”

Guidelines on Optical Coherence Tomography Angiography Imaging: 2020 Focused Update

“…Flow voids (also known as signal voids) are small dark areas that characterize OCTA images of the CC and are thought to constitute CC vascular dropout or flow reduction. Flow voids have been fully characterized in healthy and pathologic conditions [2,[29][30][31][32][33][34][35].…”

“…In order to quantify the CC perfusion, en face OCTA images of this vascular layer may be binarized to separate pixels constituting these images into two groups: one that represents the vasculature and another representing flow deficits (FDs). Although a global threshold may be used to obtain binarized images of the CC, this approach may be problematic in the presence of pathologic conditions (e.g., drusen, intraretinal exudates) that may cause local changes in image brightness that may be erroneously identified as flow voids [31,32,34,36,37]. In order to mitigate this issue, most previous studies adopted a local threshold (Phansalkar method) which uses a small window rather than the whole image to determine the threshold for binarization.…”