Interferometric thermometry of ocular tissues for retinal laser therapy

David Veysset; Yueming Zhuo; Junya Hattori; Mohajeet Buckhory; Daniel Palanker

doi:10.1364/BOE.475705

Interferometric thermometry of ocular tissues for retinal laser therapy

Biomed Opt Express. 2022 Dec 5;14(1):37-53. doi: 10.1364/BOE.475705. eCollection 2023 Jan 1.

Authors

David Veysset^{1

2}, Yueming Zhuo^{1

3}, Junya Hattori^{1

4}, Mohajeet Buckhory^{1

2}, Daniel Palanker^{1

2

5}

Affiliations

¹ Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305, USA.
² Department of Ophthalmology, Stanford University, Stanford, CA 94305, USA.
³ Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA.
⁴ Department of Mechanical Engineering, The University of Tokyo, Tokyo, Japan.
⁵ palanker@stanford.edu.

Abstract

Controlling the tissue temperature rise during retinal laser therapy is highly desirable for predictable and reproducible outcomes of the procedure, especially with non-damaging settings. In this work, we demonstrate a method for determining the optical absorption, the thermal conductivity, and the thermal expansion coefficients of RPE and choroid using phase-resolved optical coherence tomography (pOCT). These parameters are extracted from the measured changes in the optical path length (ΔOPL) using an axisymmetric thermo-mechanical model. This allows the calculation of the temperature rise during hyperthermia, which was further validated by imaging the temperature-sensitive fluorescence at the same location. We demonstrate that, with a temperature uncertainty of ±0.9°C and a peak heating of about 17°C following a laser pulse of 20 ms, this methodology is expected to be safe and sufficiently precise for calibration of the non-damaging retinal laser therapy. The method is directly translatable to in-vivo studies, where we expect a similar precision.

Abstract

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