In-vivo imaging of the palisades of Vogt and the limbal crypts with sub-micrometer axial resolution optical coherence tomography

Abstract

A research-grade OCT system was used to image in-vivo and without contact with the tissue, the cellular structure and microvasculature of the healthy human corneo-scleral limbus. The OCT system provided 0.95 µm axial and 4 µm (2 µm) lateral resolution in biological tissue depending on the magnification of the imaging objective. Cross-sectional OCT images acquired tangentially from the inferior limbus showed reflective, loop-like features that correspond to the fibrous folds of the palisades of Vogt (POV). The high OCT resolution allowed for visualization of individual cells inside the limbal crypts, capillaries extending from the inside of the POV's fibrous folds and connecting to a lateral grid of micro-vessels located in the connective tissue directly below the POV, as well as reflections from individual red blood cells inside the capillaries. Difference in the reflective properties of the POV was observed among subjects of various pigmentation levels of the POV. Morphological features observed in the high resolution OCT images correlated well with histology. The ability to visualize the limbal morphology and microvasculature in-vivo at cellular level can aid the diagnostics and treatment of limbal stem cell dysfunction and dystrophies. a novel anatomical structure and a putative limbal stem cell niche," Br.

Real-time non-contact cellular imaging and angiography of human cornea and limbus with common-path full-field/SD OCT

“…6e) and their dark shadows ( Fig. 6d) appeared to protrude from inside of the palisades, in agreement with the literature 33,34,35 . These vessels, parallel to the ocular surface, appeared to be connected with a perpendicular oriented vessel network, visible as dark round shadows (Fig.…”

“…Comparing to our previous preliminary work 10 underlying vessels, compared to UHR-OCT 35 and IVCM 39 . Furthermore, our instrument is not limited to diagnosis of "static" corneal disorders, but can potentially monitor inflammatory and scarring conditions affecting the dynamics of the blood flow in the eye.…”

Recent Advances in Stem Cell Therapy for Limbal Stem Cell Deficiency: A Narrative Review

“…Its strength lies in detecting precise changes in the 3D structure of the limbus (Fig. 1c) [5,52], as scans may be taken and reconstructed in parallel, perpendicular, and en face planes relative to the limbus [33]. Loss of stromal undulations and normal epithelial thickening in the limbus can be detected early with AS-OCT, as can loss of clear transition between corneal epithelium and conjunctival epithelium [32].…”

Bildgebung in der Kornea mittels optischer Kohärenztomografie – historische Entwicklung und neueste technische Fortschritte

“…Diese Limbusstammzellen differenzieren sich zu Epithelzellen und regenerieren die Epithelzellschicht so von innen nach außen. Mithilfe eines OCT-Prototypen mit einer Auflösung von weniger als 1 µm im Gewebe konnten Bizheva und Kollegen detaillierte Schnittbilder und 3-dimensionale Aufnahmen der Vogt-Palisaden und der limbalen Krypten, die Sitz der Stammzellen sind, gewinnen [38]. In ▶ Abb.…”

“…Die grünen Pfeile markieren pigmentierte Epithelzellen. Des Weiteren sind die Zellkerne von limbalen Epithelzellen (rote Pfeile) und rote Blutkörperchen (gelbe Markierungen) in den Blutgefäßen des Limbus zu erkennen[38] [rerif].Die zelluläre Auflösung der Messmethode mit der Möglichkeit zur Detektion von Veränderungen in den Zellverbänden kann sowohl die Diagnose und Behandlung der limbalen Stammzellinsuffizienz unterstützen als auch wichtige Aufschlüsse hinsichtlich der Heilungsfähigkeit des Epithels durch die Differenzierung der Stammzellen geben.Die UHR-OCT kann außerdem unterstützend für andere bildgebende bzw. diagnostische Methoden eingesetzt werden.…”