Imaging retinal metabolic changes with spectroscopic optical coherence tomography

This is a project in collaboration with Optos (https://www.optos.com/) supervised by Dr Pierre Bagnaninchi (http://www.crm.ed.ac.uk/research/associate/cell-and-tissue-monitoring), Prof. Bal Dhillon and Dr. Colin Campbell.


Imaging retinal metabolic changes with spectroscopic optical coherence tomography

Oxygen metabolism plays a central role in major eye diseases such as glaucoma, age-related macular degeneration (AMD) and diabetic retinopathy. Optical coherence tomography is an established clinical imaging modality to assess microstructural changes in retinal layers. It generally uses near infrared light to provide label-free deep imaging. In this proposal, we wish to explore in collaboration with Optos, a leading retinal imaging company, the potential of spectroscopic OCT to image retinal metabolic changes relevant to eye diseases.

The Ph.D. candidate will first develop a dual-modality OCT-fluorescence based on a spectral domain interferometer to facilitate its adoption to an existing instrument. Then she/he will use the new modality to image in depth (<2mm) molecular information from commercial fluorescent probes and pathological microstructure alterations from OCT in vitro. In addition, oxygen saturation measurements will be performed at each pixel of the 3D image by exploiting the crossover behavior of hemoglobin and oxyhemoglobin (HbO2) absorption coefficients around 800 nm. Novel metabolic signatures will be further investigated by Raman spectroscopy to help establish S-OCT findings. Finally, the Core Technology Research Group of Optos will help guide the project with direction on medical device compliance, retinal imaging and commercialisation.

The ability of S-OCT to generate depth-resolved fluorescence images (<2mm) of metabolic biomarkers will be validated by imaging stem-cell-based in vitro models of AMD developed by Prof. Baljean Dhillon’s team, and corroborated to fluorescent assays and Raman spectroscopy in Dr. Campbell’s lab. 3D mapping of oxygen saturation will be calibrated on bovine whole blood flow driven through microfluidic channels and correlated to blood analyser readings. The student will gain an interdisciplinary profile developing a smart diagnostic tool with physicists, clinicians and chemists to evaluate the system and push its translation into clinical diagnosis. She/he will benefit from the opportunity to undertake short internships at Optos to work on specific sub-projects .