gms | German Medical Science

102. Jahrestagung der DOG

Deutsche Ophthalmologische Gesellschaft e. V.

23. bis 26.09.2004, Berlin

Selective retinal treatment (SRT): analysis of optoacoustic online dosimetry

Meeting Abstract

  • corresponding author E. Pörksen - University Eye Clinic, Lübeck
  • H. Elsner - University Eye Clinic, Lübeck
  • D. Theissen-Kunde - Med Laser Ctr Lübeck, Lübeck
  • H. Roider - University Eye Clinic, Kiel
  • R. Birngruber - Med Laser Ctr Lübeck, Lübeck
  • R. Brinkmann - Med Laser Ctr Lübeck, Lübeck

Evidenzbasierte Medizin - Anspruch und Wirklichkeit. 102. Jahrestagung der Deutschen Ophthalmologischen Gesellschaft. Berlin, 23.-26.09.2004. Düsseldorf, Köln: German Medical Science; 2004. Doc04dogDO.03.02

The electronic version of this article is the complete one and can be found online at:

Published: September 22, 2004

© 2004 Pörksen et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.




Selective retina treatment (SRT) is evaluated in a clinic multicenter trial for patients with diabetic maculopathie and macula edema after retinal vein occlusion. The selective absorption of the laser energy at the melanosomes within retinal pigmentepithilium cells (RPE) forms microbubbles, leading to celldisrupture, sparing retinal photoreceptors. The laserspots are primarily ophthalmoscopic invisible. In order to control dosimetry Indocyaningreen- and Fluoresceinangiographie (ICG-/FLA) were performed postop. to visualise RPE-defect. The microbubble-formation is registrated by an microphone integrated into the contact lense. This optoacoustic procedure is used for dosimitry and is to be evaluated.


In Lübeck 27 patients were treated with an pulsed frequency-doubled Q-switched Nd:YLF-Laser (527nm, each spot with 30 pulses of 1,7μs duration at 100Hz). At the same time the optoacoustic signal was recorded by the microphone and a computed optoacoustic value (OA) was presented to the surgeon (range 0-4). Afterwards the data were analyzed and correlated to the postop recorded ICG-FLA.


The analysis of the optoacoustic and ICG-/FLA data showed, that at an OA-threshold of 0.137 in more than 95% and beyond 0.15 in 100% RPE-lesions were produced by the laserexposition. Below this threshold in less then 30% lesions were visible in ICG-/FLA. In rarely cases ophthalmoscopic lesions were produced (OA>1). As a therapeutic range the intervall of 0.15 to 0.4 was determined.


The optoacoustic online dosimitry proved to be a valid means in SRT. The OA is a reliable parameter for created RPE-lesions. Due to optoacoustic online dosimetry SRT becomes more save, simplified and efficiant.