@inproceedings{Herrmann2007,
   author = {Herrmann, Katharina and Flöhr, Christian and Stalljohann, Jens and Apiou-Sbirlea, Gabriela and Kandulla, Jochen and Birngruber, Reginald and Brinkmann, Ralf},
   title = {Influence of choroidal perfusion on retinal temperature increase during retinal laser treatments},
   volume = {6632},
   pages = {66321D-66321D-7},
   note = {10.1117/12.728222},
   abstract = {In most retinal laser treatments the therapeutic effect is initiated by a transient temperature increase at and around the retinal pigment epithelium (RPE). Especially in long exposure time treatments like Transpupillary Thermotherapy (TTT) choroidal perfusion has a strong influence on the realized temperature at the fundus. The fundus blood circulation and therefore the heat dissipation is influenced by the intraocular pressure (IOP), which is investigated in the study presented here. In order to reduce the choroidal perfusion, the IOP is increased by injection of physiological saline solution into the eye of anaesthetized rabbits. The fundus is irradiated with 3.64 W/cm2 by means of a TTT-laser (λ = 810 nm) for t = 20 s causing a retinal temperature increase. Realtime temperature determination at the irradiated spot is achieved by a non invasive optoacoustic technique. Perfusion can be reduced by increasing IOP, which leads to different temperature increases when irradiating the retina. This should be considered for long time laser treatments.},
   url = {http://dx.doi.org/10.1117/12.728222},
   type = {Conference Proceedings},
year = { 2007}
}

@inproceedings{Schlott2007,
   author = {Schlott, Kerstin and Stalljohann, Jens and Weber, Benjamin and Kandulla, Jochen and Herrmann, Katharina and Birngruber, Reginald and Brinkmann, Ralf},
   title = {Optoacoustic online temperature determination during retinal laser photocoagulation},
   volume = {6632},
   pages = {66321B-66321B-8},
   note = {10.1117/12.728291},
   abstract = {Retinal photocoagulation is an established treatment of different retinal diseases. The treatment relies on a short, local heating of the tissue which induces a denaturation. The resulting scar formation may for example prevent the further detachment of the retina. The extent of the coagulation is besides other parameters mostly dependent on the induced temperature increase. However, until today a temperature based dosimetry for photocoagulation does not exist. The dosage is rather based on the experience of the treating physicians to achieve visible whitish lesions on the retina. In this work a technique is presented, which allows an online temperature monitoring during photocoagulation. If an absorbing material is irradiated with short laser pulses, a thermoelastic expansion of the absorber induces an acoustic wave. Its amplitude is dependent on the temperature of the absorber. For analyzing the applicability of the optoacoustic temperature determination for dosimetry, measurements were performed on enucleated porcine eye globes. The pressure transients are detected by an ultrasonic transducer, which is embedded in an ophthalmologic contact lens. As long as no strong lesions occur, the determined temperatures are almost proportional to the power of the treatment laser. Using a spot diameter of 200 μm and different laser powers, the temperature rise at the end of the 400 ms irradiation was found to be approximately 0.16 °C/mW. The onset of the denaturation was observed around 50°C. The far aim of this project is an automatic regulation of the treatment laser onto a desired temperature course.},
   url = {http://dx.doi.org/10.1117/12.728291},
   type = {Conference Proceedings},
year = { 2007}
}

@inproceedings{Schuele-2002,
   author = {Schuele, Georg and Huettmann, Gereon and Brinkmann, Ralf},
   title = {Noninvasive temperature measurements during laser irradiation of the retina with optoacoustic techniques},
   editor = {Fabrice, Manns and Per, G. Soederberg and Arthur, Ho},
   publisher = {Proc. SPIE},
   volume = {4611},
   pages = {64-71},
year = { 2002},
url = { https://doi.org/10.1117/12.470601} 
}

@inproceedings{Rommerscheid2001,
   author = {Rommerscheid, Jan and Theisen, Dirk and Schmuecker, G. and Brinkmann, Ralf and Broll, R.},
   title = {Myocardial expression of the vascular endothelial growth factor (VEGF) after endocardial laser revascularization (ELR)},
   volume = {4433},
   pages = {39-44},
   note = {10.1117/12.446529},
   abstract = {Background. Endocardial laser revascularization (ELR) is a new technique to treat patients with severe coronary artery disease (CAD) in a percutaneous approach. The results show a significant improvement of symptoms, but the mechanism of action is still unknown. One main theory is the angiogenesis for which Vascular Endothelial Growth Factor (VEGF) is the keypromotor. We investigated immunohistochemically the VEGF-expression after ELR in porcine hearts over a timeperiod of four weeks. Methods. ELR was performed with a single-pulse Thulium:YAG laser. 15 pigs were treated with ELR and the hearts were harvested at five timeperiods: directly (group I), 3 days (group II), 1 week (group III), 2 weeks (group IV) and 4 weeks (group V) after ELR. Each group consisted of three pigs. Immunohistochemically the VEGF-expression was assessed by staining with a polyclonal antibody against VEGF and cellcounting using an expression index (VEGF-EI) Results. A maximum of VEGF-expression was found three days (group II) after ELR with a VEGF-EI of 97%. At 1 week (group III) the VEGF-EI was similar high with 93%. Along the timecourse the index decreased to 22% at 4 weeks (groupV). Conclusions. Our findings show that ELR leads to an local upregulation of VEGF around the channels. The resulting angiogenesis could be the mechanism for the relief of angina.},
   url = {http://dx.doi.org/10.1117/12.446529},
   type = {Conference Proceedings},
year = { 2001}
}