RESEARCH ARTICLE


Photoacoustic Imaging of Enucleated Eyes from Patients with Uveal Melanoma can Reveal Extrascleral Growth



Ulf Dahlstrand1, *, Aboma Merdasa1, Jenny Hult1, John Albinsson1, Magnus Cinthio2, Rafi Sheikh1, Malin Malmsjö1
1 Department of Clinical Sciences Lund, Ophthalmology, Lund University, Skåne University Hospital, Lund, Sweden
2 Department of Biomedical Engineering, Faculty of Engineering, Lund University, Lund, Sweden


© 2021 Dahlstrand et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Department of Clinical Sciences Lund, Ophthalmology, Lund University, Skåne University Hospital, Lund, Ögonklinik A, Kioskgatan 1, Skåne University Hospital SE-221 85 Lund, Sweden; Tel: +4640331349; E-mail: ulf.dahlstrand@med.lu.se


Abstract

Background:

Uveal melanoma is treated by either enucleation (removal of the eye) or local eye-sparing therapies, depending on tumor size and whether there are signs of extrascleral growth. Photoacoustic (PA) imaging is a novel imaging modality that provides high-resolution images of the molecular composition of tissues.

Objective:

In this study, the feasibility of PA imaging for uveal melanomas and detection of extrascleral growth was explored.

Methods:

Seven enucleated human eyes with uveal melanomas were examined using PA imaging. The spectral signatures of the melanomas and the layers of the normal eyewall were characterized using 59 excitation wavelengths from 680 to 970 nm.

Results:

Significant differences were seen between the spectra obtained from melanoma and the healthy eyewall. Using spectral unmixing, melanin, hemoglobin and collagen could be mapped out, showing the architecture of the tumor in relation to the eyewall. This allowed visualization of regions where the tumor extended into the extrascleral space.

Conclusion:

PA imaging appears to have the potential to aid in assessing uveal melanomas and as a diagnostic tool for the detection of extrascleral growth.

Keywords: Enucleation, Ex vivo, Photoacoustic imaging, Spectral unmixing, Tumor, Uveal melanoma.