Noninvasive temperature measurements during laser irradiation of the retina with optoacoustic techniques

Georg Schuele; Gereon Huettmann; Ralf Brinkmann

doi:10.1117/12.470601

13 June 2002 Noninvasive temperature measurements during laser irradiation of the retina with optoacoustic techniques

Georg Schuele, Gereon Huettmann, Ralf Brinkmann

Proceedings Volume 4611, Ophthalmic Technologies XII; (2002) https://doi.org/10.1117/12.470601
Event: International Symposium on Biomedical Optics, 2002, San Jose, CA, United States

Abstract

In all laser treatments at the fundus of the eye the temperature increase is unknown. In order to optimize the treatment modalities, a noninvasive online temperature determination is preferable. Applying laser pulses to the fundus, thermoelastic stress waves are emitted based on the thermal expansion of the heated tissue, mainly the retinal pigment epithelium (RPE). The amplitude of the thermoelastic wave is proportional to the thermal expansion coefficient, which linearly depends on temperature between 30-80 degree(s)C for water. The method was evaluated for selective RPE- treatment in vitro and clinically using the microsecond(s) -laser pulses for treatment and temperature determination simultaneously. Conventional laser photocoagulation was investigated in vitro using an Ar Ion laser for coagulation and low-energy N₂-pumped dye laser pulses to probe the temperature. In all cases, sufficient pressure amplitudes were detected either by a needle hydrophon in vitro or by a contact lens with embedded transducer during treatment. Depending on the treatment parameter, temperature increase of 60 degree(s)C were evaluated from the pressure transients. All temperatures detected are in close agreement to heat diffusion calculations. We demonstrated a noninvasive online method to detect retinal temperatures during laser treatments. This technique can be adapted to photocoagulation, PDT and TTT.

Citation Download Citation

Georg Schuele, Gereon Huettmann, and Ralf Brinkmann "Noninvasive temperature measurements during laser irradiation of the retina with optoacoustic techniques", Proc. SPIE 4611, Ophthalmic Technologies XII, (13 June 2002); https://doi.org/10.1117/12.470601

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available