Biomaterial Database

[Effects of Nd:YAG microexplosions on heparin-coated PMMA intraocular lenses]. 1995

T Kohnen, and B Dick, and K W Jacobi

Universitts-Augenklinik Giessen.

Surface modification of intraocular lenses (IOL) have improved the quality of cataract surgery. Heparin surface-modified (HSM) IOL are implanted for special indications (e.g., recurrent uveitis, cataract surgery for children, preoperative synechia) because of decreased postoperative inflammatory reactions and higher long-term biocompatibility. Nevertheless, secondary cataract, precipitates and fibrinous membranes appear. The YAG laser is used for treatment. METHODS PMMA intraocular lenses with or without a heparin monolayer were exposed to Nd:YAG laser. The experiment was performed under BSS using different energy levels and distances to the IOL. The heparin monolayer was stained with toluidin blue. Subsequently, the surface of the intraocular lenses was examined with light and scanning electron microscopy. RESULTS The YAG laser marks of HSM IOL and PMMA IOL showed no morphological differences. Microexplosions and pressure waves of the Nd:YAG laser cleared parts of the heparin monolayer in the area of the laser spots dependent on energy distance to the IOL. Even "breakdown" behind the HSM IOL without any PMMA lesion shown circular destruction of the heparin monolayer. CONCLUSIONS The heparin surface defect of HSM IOL after YAG laser treatment should be taken into consideration, because a decreased heparin effect in vivo could be possible.

UI	MeSH Term	Description	Entries
D007910	Lenses, Intraocular	Artificial implanted lenses.	Implantable Contact Lens,Lens, Intraocular,Contact Lens, Implantable,Intraocular Lens,Intraocular Lenses,Lens, Implantable Contact
D008768	Methylmethacrylates	The methyl esters of methacrylic acid that polymerize easily and are used as tissue cements, dental materials, and absorbent for biological substances.
D008855	Microscopy, Electron, Scanning	Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.	Scanning Electron Microscopy,Electron Scanning Microscopy,Electron Microscopies, Scanning,Electron Microscopy, Scanning,Electron Scanning Microscopies,Microscopies, Electron Scanning,Microscopies, Scanning Electron,Microscopy, Electron Scanning,Microscopy, Scanning Electron,Scanning Electron Microscopies,Scanning Microscopies, Electron,Scanning Microscopy, Electron
D006493	Heparin	A highly acidic mucopolysaccharide formed of equal parts of sulfated D-glucosamine and D-glucuronic acid with sulfaminic bridges. The molecular weight ranges from six to twenty thousand. Heparin occurs in and is obtained from liver, lung, mast cells, etc., of vertebrates. Its function is unknown, but it is used to prevent blood clotting in vivo and vitro, in the form of many different salts.	Heparinic Acid,alpha-Heparin,Heparin Sodium,Liquaemin,Sodium Heparin,Unfractionated Heparin,Heparin, Sodium,Heparin, Unfractionated,alpha Heparin
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D013499	Surface Properties	Characteristics or attributes of the outer boundaries of objects, including molecules.	Properties, Surface,Property, Surface,Surface Property
D053685	Laser Therapy	The use of photothermal effects of LASERS to coagulate, incise, vaporize, resect, dissect, or resurface tissue.	Laser Knife,Laser Scalpel,Surgery, Laser,Vaporization, Laser,Laser Ablation,Laser Knives,Laser Photoablation of Tissue,Laser Surgery,Laser Tissue Ablation,Nonablative Laser Treatment,Pulsed Laser Tissue Ablation,Ablation, Laser,Ablation, Laser Tissue,Knife, Laser,Knifes, Laser,Knive, Laser,Knives, Laser,Laser Knifes,Laser Knive,Laser Scalpels,Laser Surgeries,Laser Therapies,Laser Treatment, Nonablative,Laser Treatments, Nonablative,Laser Vaporization,Nonablative Laser Treatments,Scalpel, Laser,Scalpels, Laser,Surgeries, Laser,Therapies, Laser,Therapy, Laser,Tissue Ablation, Laser