Biomaterial Database

[Effect of pulse duration of the Er:YAG laser on photoablation in ocular tissue (cornea and sclera)]. 1993

T Bende, and B Jean, and M Matallana, and T Seiler, and R Steiner

Abt. I, Universitäts-Augenklinik Tübingen.

After photoablation in corneal and scleral tissue with the Er:YAG laser, two zones of thermal damage can be detected: The first zone (about 3 microns thick) consists of thermally denatured debris. The second zone (about 30 microns thick) shows a slightly more intense staining (H&E) compared to the non-influenced tissue. Variation of laser pulse duration between 100 microseconds and 1300 microseconds does not influence the extension of these two thermal damage zones. Furthermore, ablation rate and ablation volume remain nearly constant within this range of pulse durations. These data were obtained by histology (H&E staining) and with a recently published silicon cast replica method. All experiments have been performed on corneas and sclera of pig eyes.

UI	MeSH Term	Description	Entries
D007834	Lasers	An optical source that emits photons in a coherent beam. Light Amplification by Stimulated Emission of Radiation (LASER) is brought about using devices that transform light of varying frequencies into a single intense, nearly nondivergent beam of monochromatic radiation. Lasers operate in the infrared, visible, ultraviolet, or X-ray regions of the spectrum.	Masers,Continuous Wave Lasers,Pulsed Lasers,Q-Switched Lasers,Continuous Wave Laser,Laser,Laser, Continuous Wave,Laser, Pulsed,Laser, Q-Switched,Lasers, Continuous Wave,Lasers, Pulsed,Lasers, Q-Switched,Maser,Pulsed Laser,Q Switched Lasers,Q-Switched Laser
D008028	Light Coagulation	The coagulation of tissue by an intense beam of light, including laser (LASER COAGULATION). In the eye it is used in the treatment of retinal detachments, retinal holes, aneurysms, hemorrhages, and malignant and benign neoplasms. (Dictionary of Visual Science, 3d ed)	Photocoagulation,Coagulation, Light,Coagulations, Light,Light Coagulations,Photocoagulations
D003315	Cornea	The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous CORNEAL EPITHELIUM; BOWMAN MEMBRANE; CORNEAL STROMA; DESCEMET MEMBRANE; and mesenchymal CORNEAL ENDOTHELIUM. It serves as the first refracting medium of the eye. It is structurally continuous with the SCLERA, avascular, receiving its nourishment by permeation through spaces between the lamellae, and is innervated by the ophthalmic division of the TRIGEMINAL NERVE via the ciliary nerves and those of the surrounding conjunctiva which together form plexuses. (Cline et al., Dictionary of Visual Science, 4th ed)	Corneas
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012590	Sclera	The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. It receives the tendons of insertion of the extraocular muscles and at the corneoscleral junction contains the CANAL OF SCHLEMM. (From Cline et al., Dictionary of Visual Science, 4th ed)	Scleral Spur,Scleral Spurs,Scleras