Ellipsoid zone on optical coherence tomography: a review

Abstract

Emergence of the high-resolution optical coherence tomography has allowed better delineation of retinal layers, and many of the anatomical correlations of these layers have now been agreed upon. However, some anatomical correlates still remain contentious, such as the second hyper-reflective band, which is now termed ellipsoid zone. Despite the lack of consensus of the actual origin of the ellipsoid zone, there has been much interest in evaluating its integrity and intensity in different disease processes. This review paper aims to provide an overview of the ellipsoid zone and its clinical and research applications.

Evaluation of retinal morphology of canine sudden acquired retinal degeneration syndrome using optical coherence tomography and fluorescein angiography

“…The fovea has four distinct bands, whereas more peripheral retina has three bands. The innermost band correlates with the external limiting membrane, the second band corresponds to the ellipsoid layer of the photoreceptor inner segments, the third band corresponds to the contact cylinder or the interdigitating zone and the fourth band corresponds to the RPE and Bruch's membrane complex . In the canine control dogs in this study, three OCT bands were present in all quadrants measured (Figure A), likely corresponding to the external limiting membrane, the mitochondria‐rich area in the inner photoreceptor segments (ellipsoid) and the RPE photoreceptor interdigitations.…”

Quantitative Analysis of the Ellipsoid Zone Intensity in Phenotypic Variations of Intermediate Age-Related Macular Degeneration

“…We and others have suggested a role for the second hyperreflective band, seen in the outer retina, as a marker of disease severity in various inflammatory diseases [6][7][8] as well as retinal inherited and degenerative conditions. [9][10][11] Although previously referred to as the inner segment-outer segment (IS/OS) junction, the reflectivity of this band has more recently been suggested to originate from the photoreceptor IS ellipsoids, 12,13 thus it was referred to as the ellipsoid zone (EZ) at a recent international OCT nomenclature meeting. 14 The photoreceptor IS ellipsoids are densely packed with mitochondria, and have important metabolic and light guiding roles.…”

The Characteristics of Patient with Macular Hole After Pars Plana Vitrectomy (PPV) and Internal Limiting Membran (ILM) Peeling in Cicendo Eye Hospital National Eye Center, Bandung

“…The diameter of the macular hole measured by OCT at the level of the retinal pigment epithelium and the minimum diameter seem to provide a prognostic factor for postoperative visual outcome and anatomical success of macular hole surgery. [6][7][8] The hole form factor (HFF) is the first calculated OCT index used as a prognostic factor. The HFF is the quotient of the summation of the left and right arm lengths divided by the basal hole diameter.…”

“…In this study mean HFF value in closed MH was 1,34 ± 0,90 before surgery (n=20) and in unclosed MH HFF value was 0,53 ± 0,12 (n=7). [6][7][8] MH index (MHI) is an intuitive predictor for visual outcome following MH surgery. The MHI is defined as the ratio of the hole height to the basal hole diameter and is reported to be positively correlated to the postoperative visual acuity in several studies.…”

“…In this study, we found that MHI value in closed MH before surgery was 1,09 ± 0,81µm (n=20) and compare to unclosed MHI 0,53±0,15µm (n=7) after surgery. [7][8][9]10 The ILM is the basal lamina of the inner retina and is thought to be a scaffold for proliferation of fibrocytes, myofibroblasts, and retinal pigment epithelial cells. ILM peeling increases the likelihood of successful macular hole closure, but, because the ILM also plays a role in the structural integrity of the retina, it has been postulated that removal of this membrane could be functionally damaging to the retina.…”