Biomaterial Database

Acoustic transients following excimer laser ablation of the cornea. 1995

P G Gobbi, and F Carones, and R Brancato, and R Pini, and S Siano

Laser Medicine Research, Scientific Institute H S. Raffaele, Milano, Italy.

Pressure transients occurring inside the eyeball as a consequence of excimer laser ablation of the cornea were measured at various distances along the optical axis, on enucleated porcine eyes. Positive (compressive) pressure spikes up to 90 bars were observed, lasting 100 ns, and developing, as they propagated in the eyeball, satellite rarefaction pulses with negative pressure as high as -40 bar. Such rarefaction wavefronts can trigger the formation of cavitation bubbles, in both the anterior and posterior chamber, depending on the ablation geometry. The potential risks associated with these photoacoustic phenomena, particularly for retina and corneal endothelium, are outlined.

UI	MeSH Term	Description	Entries
D011184	Postoperative Period	The period following a surgical operation.	Period, Postoperative,Periods, Postoperative,Postoperative Periods
D011312	Pressure	A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Pressures
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
D000162	Acoustics	The branch of physics that deals with sound and sound waves. In medicine it is often applied in procedures in speech and hearing studies. With regard to the environment, it refers to the characteristics of a room, auditorium, theatre, building, etc. that determines the audibility or fidelity of sounds in it. (From Random House Unabridged Dictionary, 2d ed)	Acoustic
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
D013552	Swine	Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).	Phacochoerus,Pigs,Suidae,Warthogs,Wart Hogs,Hog, Wart,Hogs, Wart,Wart Hog
D054018	Lasers, Excimer	Gas lasers with excited dimers (i.e., excimers) as the active medium. The most commonly used are rare gas monohalides (e.g., argon fluoride, xenon chloride). Their principal emission wavelengths are in the ultraviolet range and depend on the monohalide used (e.g., 193 nm for ArF, 308 nm for Xe Cl). These lasers are operated in pulsed and Q-switched modes and used in photoablative decomposition involving actual removal of tissue. (UMDNS, 2005)	Argon Fluoride Excimer Lasers,Excimer Lasers,Krypton Chloride Excimer Lasers,Xenon Chloride Excimer Lasers,ArF Excimer Lasers,ArF Lasers,Argon Fluoride Lasers,Excimer Laser,Excimer Lasers, ArF,Excimer Lasers, Argon Fluoride,Excimer Lasers, KrCl,Excimer Lasers, Krypton Chloride,Excimer Lasers, XeCl,Excimer Lasers, Xenon Chloride,KrCl Excimer Lasers,Krypton Chloride Lasers,Lasers, ArF Excimer,Lasers, Argon Fluoride Excimer,Lasers, KrCl,Lasers, Krypton Chloride,Lasers, Krypton Chloride Excimer,Lasers, XeCl Excimer,Lasers, Xenon Chloride,Lasers, Xenon Chloride Excimer,XeCl Lasers,Xenon Chloride Lasers,ArF Excimer Laser,ArF Laser,Argon Fluoride Laser,Chloride Laser, Krypton,Chloride Laser, Xenon,Chloride Lasers, Krypton,Chloride Lasers, Xenon,Excimer Laser, ArF,Excimer Laser, KrCl,Excimer Laser, XeCl,Fluoride Laser, Argon,Fluoride Lasers, Argon,KrCl Excimer Laser,KrCl Laser,KrCl Lasers,Krypton Chloride Laser,Laser, ArF,Laser, ArF Excimer,Laser, Argon Fluoride,Laser, Excimer,Laser, KrCl,Laser, KrCl Excimer,Laser, Krypton Chloride,Laser, XeCl,Laser, XeCl Excimer,Laser, Xenon Chloride,Lasers, ArF,Lasers, Argon Fluoride,Lasers, KrCl Excimer,Lasers, XeCl,XeCl Excimer Laser,XeCl Excimer Lasers,XeCl Laser,Xenon Chloride Laser
D018903	Photorefractive Keratectomy	A type of refractive surgery of the CORNEA to correct MYOPIA and ASTIGMATISM. An EXCIMER LASER is used directly on the surface of the EYE to remove some of the CORNEAL EPITHELIUM thus reshaping the anterior curvature of the cornea.	Keratectomies, Photorefractive,Keratectomy, Photorefractive,Photorefractive Keratectomies