Volume Rendering of Angiographic Optical Coherence Tomography Angiography in Fovea Plana and Normal Foveal Pit

Abstract

This paper aims to study adaptative vascular arrangements in idiopathic fovea plana with volume-rendered optical coherence tomography angiography (OCTA). A retrospective review of two cases of idiopathic fovea plana (mean age: 26.5 years) and two age-matched controls imaged with OCTA was conducted using spectral-domain OCTA (RTVue XR Avanti, Optovue, Inc., Fremont, CA) equipped with the AngioVue software. Both en face OCTA slabs and OCTA b scans were processed through Fiji software (http://fiji.sc; software version 2.0.0-rc-68/1.52e), and then extracted as image sequences for volume rendering reconstructions using the ImageVis3D volume rendering system (3.1.0 release). Eyes with idiopathic fovea plana demonstrated a regular superficial vascular plexus connecting to a single vascular monolayer representing the deeper vascular plexuses. At this location, several vertical short path connections were demonstrated, in contraposition with normal eyes where short path connections were infrequently observed. Advances in three-dimensional OCTA reconstruction increase the understanding of vascular connections and arrangement in retinal plexuses and possible anatomical variations that cannot be detected with conventional two-dimensional b scans.

Reconstruction and Visualization of 5μm Sectional Coronal Views for Macula Vasculature in OptoVue OCTA

“…Finally, in the literature, there are reports assessing the impact of the 3D representation of macula blood vessels [25][26][27][28][29][30][49][50][51][52]. These methods were based on surface and volumetric rendering [25, 28-30, 49, 50, 52] of the original 3D OCTA volume or they interpolated the 3D representation from 2D OCTA B-scans [26,27,51].…”

“…These methods were based on surface and volumetric rendering [25, 28-30, 49, 50, 52] of the original 3D OCTA volume or they interpolated the 3D representation from 2D OCTA B-scans [26,27,51]. They succeeded in generating a 3D depiction of the macula's volume [25][26][27][49][50][51], or they developed methods to generate a 3D shape model [28], map [29,52], and surfacing the macula vasculature [30]. Similar to the OCTA quantitative metrics discussion in the preceding paragraph, the aim was to assess the integrity or the disruption of the macula blood vessels.…”

“…Additionally, other researchers investigated the use of 3D volumetric assessment to generate a 3D volume of specified macula's zones (e.g. Fovea Plana) [25], 3D presentation of the entire macula's vessels [26,27,[49][50][51], 3D shape modeling of the macula's microvasculature [28,52], or 3D metrics of the macula's vessel density [29] and surface [30]. However, considering the 3D shape of the macula, displaying sequential OCTA frames within each macula's layers, and improving the display of vessels at deep regions (i.e.…”

Characterizing Foveal Hypoplasia Using Optical Coherence Tomography Angiography: Evaluation of Microvascular Abnormalities and Clinical Significance

“…While previous studies have explored structural and functional abnormalities in FH, limited research has focused on specific changes in retinal FD and FAZ parameters in OCTA imaging. Due to the relative rarity of FH and the novelty of OCTA technology, most studies reporting on changes in microvascular parameters in FH patients have been limited to case series, depicting qualitative rather than quantitative data [9][10][11][12][13][14][15][16][17]. The studies which report quantitative data have demonstrated that while FH is associated with a reduction in FD in whole en face scans, it shows increased FD values in the foveal sector in the inner retinal plexus [18,19].…”

Reference database of total retinal vessel surface area derived from volume-rendered optical coherence tomography angiography

“…In addition to magnetic resonance imaging, OCT and OCTA have emerged as beneficial imaging tools in multiple sclerosis 15 . The retinal vessel volume-rendering showed the altered microcirculation in the macula, for example in fovea plana, which is important because these eyes cannot fit into the scheme of normative data banks offered by the commercial manufacturers 16 .…”