Power-controlled temperature guided retinal laser therapy

Alexander Baade*, Claus Von Der Burchard, Meike Lawin, Stefan Koinzer, Benedikt Schmarbeck, Kerstin Schlott, Yoko Miura, Johann Roider, Reginald Birngruber, Ralf Brinkmann

*Corresponding author for this work
2 Citations (Scopus)

Abstract

Laser photocoagulation has been a treatment method for retinal diseases for decades. Recently, studies have demonstrated therapeutic benefits for subvisible effects. A treatment mode based on an automatic feedback algorithm to reliably generate subvisible and visible irradiations within a constant irradiation time is introduced.Themethodusesasite-individualadaptationofthelaserpowerbymonitoringtheretinaltemperature rise during the treatment using optoacoustics. This provides feedback to adjust the therapy laser power during the irradiation. The technique was demonstrated on rabbits in vivo using a 532-nm continuous wave Nd:YAG laser. The temperature measurement was performed with 523-nm Q-switched Nd:YLF laser pulses with 75-ns pulse duration at 1-kHz repetition rate. The beam diameter on the fundus was 200 m for both lasers, respectively. The aim temperatures ranged from 50°C to 75°C in 11 eyes of 7 rabbits. The results showed ophthalmoscopically invisible effects below 55°C with therapy laser powers over a wide range. The standard deviation for the measured temperatures ranged from 2.1°C for an aim temperature of 50°C to 4.7°C for 75°C. The ED50 temperature value for ophthalmoscopically visible lesions in rabbits was determined as 65.3°C. The introduced method can be used for retinal irradiations with adjustable temperature elevations.

Original languageEnglish
Article number118001
JournalJournal of Biomedical Optics
Volume22
Issue number11
ISSN1083-3668
DOIs
Publication statusPublished - 01.11.2017

Research Areas and Centers

  • Academic Focus: Biomedical Engineering

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