Optical coherence tomography (OCT) is a non-invasive depth resolved optical imaging modality, that enables high resolution, cross-sectional imaging in biological tissues and materials at clinically relevant depths. Though OCT offers high resolution imaging, the best ultra-high-resolution OCT systems are limited to imaging structural changes with a resolution of one micron on a single B-scan within very limited depth. Nanosensitive OCT (nsOCT) is a recently developed technique that is capable of providing enhanced sensitivity of OCT to structural changes. Improving the sensitivity of OCT to detect structural changes at the nanoscale level, to a depth typical for conventional OCT, could potentially improve the diagnostic capability of OCT in medical applications. Researchers from the National University of Ireland Galway demonstrates in this paper, published by Biomedical Optics Express, the capability of nsOCT to detect structural changes deep in the rat cornea following superficial corneal injury.
Full reference: C. Lal, S. Alexandrov, S. Rani, Y. Zhou, T. Ritter, M. Leahy, “Nanosensitive optical coherence tomography to assess wound healing within the cornea”. Biomed. Opt. Express 11 (7) 3407-3422 (2020) https://doi.org/10.1364/BOE.389342
Full article here
Corneal cross‐linking (CXL) using ultraviolet‐A (UVA) irradiation with a riboflavin photosensitizer has grown from an interesting concept to a practical clinical treatment for corneal ectatic diseases globally, such as keratoconus. This research led by NUI Galway reports the application of oversampling nanosensitive OCT for probing the corneal structural alterations. The results indicate that the spatial period increases slightly after 30 minutes riboflavin instillation but decreases significantly after 30 minutes UVA irradiation following the Dresden protocol. The proposed noninvasive method can be implemented using existing OCT systems, without any additional components, for detecting nanoscale changes with the potential to assist diagnostic assessment during CXL treatment, and possibly to be a real‐time monitoring tool in clinics.
Full reference: Y. Zhou, S. Alexandrov, A. Nolan, N. Das, R. Dey and M. Leahy, “Non‐invasive detection of nanoscale structural changes in cornea associated with corneal cross‐linking treatment”. Journal of Biophotonics 13 (6) e201960234 (2020) https://doi.org/10.1002/jbio.201960234
Full article here