Femtosecond laser for glaucoma treatment: the comparison between simulation and experimentation results on ocular tissue removal

2005 ◽  
Author(s):  
Dong Xia Hou ◽  
Bryan K. A. Ngoi ◽  
Sek Tien Hoh ◽  
Lee Huat K. Koh ◽  
Yuan Zi Deng
Keyword(s):  
Femtosecond Laser ◽  
Ocular Tissue ◽  
Tissue Removal ◽  
Glaucoma Treatment

Digital-holographic analysis of femtosecond laser-induced photodisruption in ocular tissue

2014 ◽  
Author(s):  
Emanuel Saerchen ◽  
Kevin Biessy ◽  
Björn Kemper ◽  
Holger Lubatschowski
Keyword(s):  
Femtosecond Laser ◽  
Ocular Tissue

IN VITRO EXPERIMENT STUDY ON ABLATION PARAMETERS IN FEMTOSECOND LASER-OCULAR TISSUE INTERACTION

2005 ◽  
Vol 04 (04) ◽  
pp. 483-488
Author(s):  
K. A. NGOI ◽  
D. X. HOU ◽  
S. T. HOH ◽  
L. H. K. KOH ◽  
Y. Z. DENG
Keyword(s):  
Femtosecond Laser ◽  
Laser System ◽  
Pulse Length ◽  
Ocular Tissue ◽  
Vitro Experiment ◽  
In Vitro Experiment ◽  
Tissue Interaction ◽  
Cutting Effect ◽  
Relationship Of

In order to apply femtosecond laser technology in ophthalmology, especially in glaucoma treatment, femtosecond laser-ocular tissue interaction research was conducted. Focusing angle, output power, irradiance duration are three important laser parameters for ophthalmic microsurgery. In our work, the relationship of the three different laser parameter versus cutting effect was investigated respectively by an in-vitro experiment using an 800 nm-wavelength 150 fs-pulse-length laser system. This experiment aims to minimize the effects of thermal damage, while at the same time maximizing the speed or quality of the tissue ablation process. The experiment result shows that there is a great potential to optimize the surgical effects using femtosecond laser compared to that using a longer pulse laser.

Femtosecond laser for glaucoma treatment: a study on ablation energy in pig iris

2005 ◽  
Vol 19 (4) ◽  
pp. 218-222 ◽  
Author(s):  
B. K. A. Ngoi ◽  
D. X. Hou ◽  
L. H. K. Koh ◽  
S. T. Hoh
Keyword(s):  
Femtosecond Laser ◽  
Glaucoma Treatment

XRF and PIXE Analysis of light and Dark Adapted Ocular Tissue

1982 ◽  
Vol 40 ◽  
pp. 190-191
Author(s):  
B. J. Panessa ◽  
H. W. Kraner ◽  
J. B. Warren ◽  
K. W. Jones
Keyword(s):  
Trace Metals ◽  
Pigment Epithelium ◽  
Nerve Impulse ◽  
Light Response ◽  
Ocular Tissue ◽  
Emission Spectrometry ◽  
Retinol Dehydrogenase ◽  
Pixe Analysis ◽  
X Ray ◽  
Optimal Function

During photoexcitation the retina requires specific electrolytes and trace metals for optimal function (Na, Mg, Cl, K, Ca, S, P, Cu and Zn). According to Hagins (1981), photoexcitation and generation of a nerve impulse involves the movement of Ca from the rhodopsin-ladened membranes of the rod outer segment (ROS) to the plasmalemma, which in turn decreases the in-flow of Na into the photoreceptor, resulting in hyperpolarization. In toad isolated retinas, the presence of Ba has been found to increase the amplitude and prolong the delay of the light response (Brown and Flaming, 1978). Trace metals such as Cu, Zn and Se are essential for the activity of the metalloenzymes of the retina and retina pigment epithelium (RPE) (i.e. carbonic anhydrase, retinol dehydrogenase, tyrosinase, glutathione peroxidase, superoxide dismutase...). Therefore the content and fluctuations of these elements in the retina and choroid are of fundamental importance for the maintenance of vision. This paper presents elemental data from light and dark adapted frog ocular tissues examined by electron beam induced x-ray microanalysis, x-ray fluorescence spectrometry (XRF) and proton induced x-ray emission spectrometry (PIXE).

Nanosecond laser-induced breakdown assisted by femtosecond laser pre-ionization in air: the effect on spatial resolution and continuous radiation

2020 ◽  
Vol 92 (2) ◽  
pp. 20701
Author(s):  
Bo Li ◽  
Xiaofeng Li ◽  
Zhifeng Zhu ◽  
Qiang Gao
Keyword(s):  
Femtosecond Laser ◽  
Spatial Resolution ◽  
Laser Induced Breakdown Spectroscopy ◽  
Nanosecond Laser ◽  
Breakdown Threshold ◽  
Powerful Technique ◽  
Breakdown Spectroscopy ◽  
Continuous Radiation ◽  
Laser Induced Breakdown

Laser-induced breakdown spectroscopy (LIBS) is a powerful technique for quantitative diagnostics of gases. The spatial resolution of LIBS, however, is limited by the volume of plasma. Here femtosecond-nanosecond dual-pulsed LIBS was demonstrated. Using this method, the breakdown threshold was reduced by 80%, and decay of continuous radiation was shortened. In addition, the volume of the plasma was shrunk by 85% and hence, the spatial resolution of LIBS was significantly improved.

Femtosecond laser assisted penetrating keratoplasty

2006 ◽  
Vol 223 (S 1) ◽  
Author(s):  
MP Holzer ◽  
TM Rabsilber ◽  
GU Auffarth
Keyword(s):  
Femtosecond Laser ◽  
Penetrating Keratoplasty
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