N
Koop,
Ralf
Brinkmann, and
G
Schirner,
Verwendung des konfokalen Laserscanverfahrens zur Bestimmung der Hornhaut-topographie und der kornealen Gewebseffekte bei der refraktiven Hornhautchirurgie: Hornhaut, Der Ophthalmologe (Berlin. Print) , vol. 93(3), pp. 247-251, 1996.
Verwendung des konfokalen Laserscanverfahrens zur Bestimmung der Hornhaut-topographie und der kornealen Gewebseffekte bei der refraktiven Hornhautchirurgie: Hornhaut, Der Ophthalmologe (Berlin. Print) , vol. 93(3), pp. 247-251, 1996.
Ralf
Brinkmann,
Juergen
Kampmeier,
Ulf
Grotehusmann,
Alfred
Vogel,
Norbert
Koop,
Mary
Asiyo-Vogel, and
Reginald
Birngruber,
Corneal collagen denaturation in laser thermokeratoplasty, 1996. pp. 56-63.
Corneal collagen denaturation in laser thermokeratoplasty, 1996. pp. 56-63.
File: | 12.239611 |
Bibtex: | ![]() @inproceedings{Brinkmann1996-7, author = {Brinkmann, Ralf and Kampmeier, Juergen and Grotehusmann, Ulf and Vogel, Alfred and Koop, Norbert and Asiyo-Vogel, Mary and Birngruber, Reginald}, title = {Corneal collagen denaturation in laser thermokeratoplasty}, volume = {2681}, pages = {56-63}, note = {10.1117/12.239611}, abstract = {In laserthermokeratoplasty (LTK) thermal denaturation and shrinkage of corneal collagen is used to correct hyperopia and astigmatism. In order to optimize dosimetry, the temperature at which maximal shrinkage of collagen fibrils occurs is of major interest. Since the exposure time in clinical LTK-treatment is limited to a few seconds, the kinetics of collagen denaturation as a rate process has to be considered, thus the time of exposure is of critical importance for threshold and shrinkage temperatures. We investigated the time-temperature correlation for corneal collagen denaturation within different time domains by turbidimetry of scattered HeNe laser probe light using a temperature controlled water bath and pulsed IR laser irradiation. In the temperature range of 60 degree(s)C to 95 degree(s)C we found an exponential relation between the denaturation time and temperature. For the typical LTK-treatment time of 2 s, a temperature of 95 degree(s)C is needed to induce thermal damage. Use of pulsed Holmium laser radiation gave significant scattering of HeNe laser probe light at calculated temperatures of around 100 degree(s)DC. Rate parameters according to the formalism of Arrhenius were fitted to these results. Force measurements showed the simultaneous onset of light scattering and collagen shrinkage.}, url = {http://dx.doi.org/10.1117/12.239611}, type = {Conference Proceedings}, Year ={ 1996} } |
F.
Schroer,
D.
Mohrenstecher,
G.
Dröge,
Ralf
Brinkmann, and
Reginald
Birngruber,
Ablation Dynamics in Laser Sclerostomy Ab-Externo, Investigative Ophthalmology & Visual Science , vol. 36, no. 4, pp. S558-S558, 1995.
Ablation Dynamics in Laser Sclerostomy Ab-Externo, Investigative Ophthalmology & Visual Science , vol. 36, no. 4, pp. S558-S558, 1995.
G.
Schirner,
Ralf
Brinkmann,
G.
Dröge,
N.
Koop,
E. S.
Elhifnawi, and
Reginald
Birngruber,
Experimental Studies to Optimize Laser-Thermokeratoplasty Using Pulsed and Cw-Laser-Sources, Investigative Ophthalmology & Visual Science , vol. 36, no. 4, pp. S716-S716, 1995.
Experimental Studies to Optimize Laser-Thermokeratoplasty Using Pulsed and Cw-Laser-Sources, Investigative Ophthalmology & Visual Science , vol. 36, no. 4, pp. S716-S716, 1995.
G.
Schirner,
N.
Koop,
E.
ElHifnawi,
Reginald
Birngruber, and
Ralf
Brinkmann,
Experiments with Pulsed and Continuous-Wave Laser Sources to Optimize Laserthermo-Keratoplasty, Vision Research , vol. 35, pp. P167-P167, 1995.
Experiments with Pulsed and Continuous-Wave Laser Sources to Optimize Laserthermo-Keratoplasty, Vision Research , vol. 35, pp. P167-P167, 1995.
G.
Schirner,
A.
Huber,
A.
Wördemann,
G.
Dröge,
E.
el-Hifnawi,
Reginald
Birngruber, and
Ralf
Brinkmann,
Experimental studies on the effect of the Er:glass and Cr:Tm:Ho:YAG laser in thermokeratoplasty, Ophthalmologe , vol. 91, no. 5, pp. 638-45, 1994.
Experimental studies on the effect of the Er:glass and Cr:Tm:Ho:YAG laser in thermokeratoplasty, Ophthalmologe , vol. 91, no. 5, pp. 638-45, 1994.
File: | query.fcgi |
Bibtex: | ![]() @article{Schirner1994, author = {Schirner, G. and Huber, A. and Wordemann, A. and Droge, G. and el-Hifnawi, E. and Birngruber, R. and Brinkmann, R.}, title = {[Experimental studies on the effect of the Er:glass and Cr:Tm:Ho:YAG laser in thermokeratoplasty]}, journal = {Ophthalmologe}, volume = {91}, number = {5}, pages = {638-45}, note = {0941-293X (Print) English Abstract Journal Article}, abstract = {So far the dose-effect ratio of the Holmium laser (wavelength 2.12 microns) and the erbium laser (1.54 microns) for laser thermokeratoplasty (LTK) are not defined in detail. Our study was designed not only to compare the erbium contact and the holmium non-contact applications but also to throw light on the influence of different geometrical application patterns, pulse energies, pulses per coagulation site and repetition rates under experimental conditions. Enucleated sheep and pig eyes were used 2-6 h post mortem, pressurized to 25 mmHg and moisturized with saline solution. Before and after LTK, pachymetry and keratometry were performed. Some specimens were prepared for light and scanning microscopy. The coagulation threshold for the erbium laser in a contact mode with a 200-microns fibre was 25 J/cm2 (ca. 8 mJ/pulse) and for the holmium laser 8 J/cm2 (ca. 2.5 mJ/pulse). The erbium laser was used in a single shot per spot mode, the holmium laser in repeated pulse per spot mode. With the single shot per spot mode, we were able to induce a promising hyperopic shift of up to -3.47 +/- 0.61 D, while myopic changes could only be induced up to +1.89 +/- 0.74 D. Higher changes of up to +8.27 +/- 1.3 D could be achieved by means of repeated pulses per spot (20 pulses, 45 mJ, 10 Hz). Our experiments showed an obvious increase of dioptric changes when using a higher repetition rate while pulse energy and number were kept constant.(ABSTRACT TRUNCATED AT 250 WORDS)}, keywords = {Animals Cornea/pathology Corneal Transplantation/*instrumentation/pathology Laser Coagulation/*instrumentation Microscopy, Electron, Scanning Myopia/pathology/surgery Refraction, Ocular Sheep Swine}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=7812097}, year = {1994}, type = {Journal Article} } |
R
Schirner,
Reginald
Birngruber, and
Ralf
Brinkmann,
Experimentelle Untersuchungen zur Wirkung des Er: Glas-und Cr: TM: Ho: YAG-Lasers bei der Thermokeratoplastik, Der Ophthalmologe (Berlin. Print) , vol. 91, no. 5, pp. 638-645, 1994.
Experimentelle Untersuchungen zur Wirkung des Er: Glas-und Cr: TM: Ho: YAG-Lasers bei der Thermokeratoplastik, Der Ophthalmologe (Berlin. Print) , vol. 91, no. 5, pp. 638-645, 1994.
Ralf
Brinkmann,
G.
Dröge,
N.
Koop,
A.
Wördemann,
G.
Schirner, and
Reginald
Birngruber,
Investigations on laser thermokeratoplasty, Lasers Light Ophthalmol , vol. 6, no. 4, pp. 259 - 270, 1994.
Investigations on laser thermokeratoplasty, Lasers Light Ophthalmol , vol. 6, no. 4, pp. 259 - 270, 1994.
R
Wetzel,
Ralf
Brinkmann, and
Reginald
Birngruber,
Laser sclerostomy ab externo using the erbium: YAG laser. First results of a clinical study, Germ j ophthal , vol. 3(2), no. 2, pp. 112-115, 1994.
Laser sclerostomy ab externo using the erbium: YAG laser. First results of a clinical study, Germ j ophthal , vol. 3(2), no. 2, pp. 112-115, 1994.
File: | query.fcgi |
Bibtex: | ![]() @article{Brinkmann1994, author = {Wetzel, W;Häring, G;Brinkmann, R and Birngruber, R}, title = {Laser sclerostomy ab externo using the erbium: YAG laser. First results of a clinical study}, journal = {Germ j ophthal}, volume = {3(2)}, pages = {112-115}, ISSN = {0941-2921}, year = {1994}, type = {Journal Article} } |
B
Knipper,
D
Jocham, and
Ralf
Brinkmann,
The Holmium-YAG-laser as a new cutting instrument in the ureter, Investigative urology (Berlin, Germany) , vol. 5, pp. 233-235, 1994.
The Holmium-YAG-laser as a new cutting instrument in the ureter, Investigative urology (Berlin, Germany) , vol. 5, pp. 233-235, 1994.
R
Engelhardt,
Ralf
Brinkmann, and
W
Meyer,
1. mu. s Alexandrit-Laser fuer laserinduzierte Schockwellenlithotripsie, Laser und Optoelektronik , vol. 21(6), pp. 56-61, 1989.
1. mu. s Alexandrit-Laser fuer laserinduzierte Schockwellenlithotripsie, Laser und Optoelektronik , vol. 21(6), pp. 56-61, 1989.
M
Hube,
Ralf
Brinkmann,
H
Welling,
R
Beigang, and
B
Wellegehausen,
A Cadmium Photoionization Laser Pumped by Laser Induced Plasma Radiation from a Multi Foci Device, Appl Phys B , vol. 45, pp. 197-201, 1988.
A Cadmium Photoionization Laser Pumped by Laser Induced Plasma Radiation from a Multi Foci Device, Appl Phys B , vol. 45, pp. 197-201, 1988.