Lipidemulsionen als Kontrastmittel für die Optische Kohärenztomographie zur Darstellung der Kammerwasserabflusswege
Lipid emulsions as contrast agents for OCT imaging of the aqueous outflow tract
von Hanna Marie Gottschalk
Datum der mündl. Prüfung:2022-07-20
Erschienen:2023-03-31
Betreuer:PD Dr. Christian van Oterendorp
Gutachter:PD Dr. Christian van Oterendorp
Gutachter:Prof. Dr. Fred Wouters
Gutachter:Prof. Dr. Wieland Staab
Dateien
Name:Dissertation_Gottschalk_Version SUB-ohne Leb...pdf
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Zusammenfassung
Englisch
Background: Glaucoma is one of the most common causes of blindness. Pathophysiologically, it is often caused by an obstruction of the aqueous outflow tract. Surgical interventions to improve the aqueous outflow are inconsistently effective, which may be due to a lack of localization of the outflow obstruction. To find an imaging technique that could visualize the aqueous humor outflow system, lipid emulsions (LE) were investigated as contrast agents for optical coherence tomography (OCT). Methods: Solutions of the anesthetic substance Propofol were infused into the anterior chamber of porcine eyes. Commercial OCT devices were applied to generate OCT images. The signal of the Propofol solution was extracted. A prototype lens for the anterior segment was used to perform OCT Angiography visualizing the LE drained via the aqueous outflow tract. For comparison with common methods fluorescence angiographic images were obtained after perfusion with indocyanine green. In addition, tissue samples were sliced after staining the aqueous veins with Trypan blue. Results: Lipid emulsions also produce a strong signal within the sclera ex vivo. It is possible to generate time-resolved images using LE-based OCT angiography. Moreover, significant anatomical differences were evident in the model eye compared to humans. In the porcine eye, no Schlemm’s canal existed and there was only a superficial but no deep venous plexus. Conclusions: The LE-based OCT angiography is a new imaging technique that allows to generate time-resolved 3D datasets of the aqueous outflow tract. Further studies are needed to determine possible interactions of LE with inner eye's structures, to improve image quality and to realize a visualization of the entire circumference of the eye.
Keywords: glaucoma; lipid emulsion; propofol; aqueous outflow; optical coherence tomography; OCTA
Schlagwörter: Glaukom; Lipidemulsion; Propofol; Kammerwasserabfluss; Optische Kohärenztomographie; OCTA