Interferometric imaging of thermal expansion for temperature control in retinal laser therapy.
Biomed Opt Express
; 13(2): 728-743, 2022 Feb 01.
Article
em En
| MEDLINE
| ID: mdl-35284191
ABSTRACT
Precise control of the temperature rise is a prerequisite for proper photothermal therapy. In retinal laser therapy, the heat deposition is primarily governed by the melanin concentration, which can significantly vary across the retina and from patient to patient. In this work, we present a method for determining the optical and thermal properties of layered materials, directly applicable to the retina, using low-energy laser heating and phase-resolved optical coherence tomography (pOCT). The method is demonstrated on a polymer-based tissue phantom heated with a laser pulse focused onto an absorbing layer buried below the phantom's surface. Using a line-scan spectral-domain pOCT, optical path length changes induced by the thermal expansion were extracted from sequential B-scans. The material properties were then determined by matching the optical path length changes to a thermo-mechanical model developed for fast computation. This method determined the absorption coefficient with a precision of 2.5% and the temperature rise with a precision of about 0.2°C from a single laser exposure, while the peak did not exceed 8°C during 1 ms pulse, which is well within the tissue safety range and significantly more precise than other methods.
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Bases de dados:
MEDLINE
Idioma:
En
Revista:
Biomed Opt Express
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Estados Unidos