chondroitin and Eye-Injuries

Topics: Animals; Basement Membrane; Cattle; Chemical Phenomena; Chemistry; Chondroitin; Choroid; Collagen; Connective Tissue; Cornea; Elastic Tissue; Electrophoresis, Disc; Eye; Eye Injuries; Galactose; Glucose; Glycine; Glycosaminoglycans; Hyaluronic Acid; Hydroxyproline; Keratins; Lens, Crystalline; Peptides; Proline; Rabbits; Sclera; Vertebrates; Vitreous Body

The use of dispersive ophthalmic viscosurgical devices (OVDs) has been shown to provide significant protection against air bubble damage to the corneal endothelium when compared with cohesive OVDs. We compared the corneal endothelial protective effects of a new dispersive OVD, Healon-D, with Viscoat.. Healon-D and Viscoat were used in a randomized and masked fashion in the anterior chamber of 40 rabbit eyes during a procedure where ultrasound at 70% continuous energy was delivered for 2 min. Two millilitres of air bubbles were injected into the anterior chamber during the first minute of the procedure on each eye. Corneas were then stained with trypan blue and alizarin red and evaluated via light microscopy for endothelial injury. Both denuding of the endothelial layer, as well as damage to endothelial cells were quantified by using the Evaluation of Posterior Capsule Opacification digital imaging system.. The denuded area for eyes treated with Healon-D and Viscoat were not significantly different (medians of 0.004167and 0.003333, respectively, P = 0.8908). There was no significant difference in the area of endothelial cell damaged (medians of 0.02183 and 0.01433, respectively, P = 0.4565). When the denuded and damaged areas were calculated together, there was also no difference in the total injured area (medians of 0.05817 and 0.05821, respectively, P = 0.5740).. The new dispersive OVD Healon-D is equally as effective as Viscoat in protecting the corneal endothelial layer from denuding and damage from air bubbles during anterior segment surgery.

Topics: Animals; Anterior Chamber; Chondroitin; Chondroitin Sulfates; Drug Combinations; Endothelium, Corneal; Eye Injuries; Hyaluronic Acid; Phacoemulsification; Rabbits; Viscoelastic Substances

Topics: Chondroitin; Chondroitin Sulfates; Drug Combinations; Eye Injuries; Humans; Hyaluronic Acid; Intraoperative Complications; Lens Capsule, Crystalline; Phacoemulsification; Rupture

To evaluate the usefulness of viscoelastic in protecting the corneal endothelium from desiccation injury associated with fluid-air exchange in a rabbit model.. Experimental study.. Rabbit eyes undergoing pars plana lensectomy and vitrectomy were insufflated with either dry or humidified air for 20 minutes following introduction of either Opegan (sodium hyaluronate 1.0%; Santen, Osaka, Japan) or Viscoat (sodium hyaluronate 3%-chondroitin sulfate 4%; Alcon, Tokyo, Japan) into the anterior chamber. In two other groups of rabbit eyes, the same procedure was performed without using any viscoelastic agent. Corneas obtained from rabbits undergoing surgery were compared with corneas obtained from rabbits not undergoing surgery. Potential alterations in the corneal endothelium were investigated by scanning electron microscopy, by Phalloidin-FITC staining of actin and by in vitro measurements of corneal permeability for carboxyfluorescein using a diffusion chamber.. Scanning electron microscopy displayed less distortion of corneal endothelium with Opegan and Viscoat compared with the dry air-only exposed corneas. Using humidified air in Opegan and Viscoat coated corneas maintained the normal actin cytoskeleton during fluid-air exchange. Paracellular leakage was much less with Opegan and Viscoat use following infusion of dry air comparing to that of dry air-only group (P =.026 and P =.041). The difference was much more striking following humidified air infusion in Opegan or Viscoat coated corneas comparing to dry air-only infused corneas (P <.002 and P <.002).. Coating of rabbit corneal endothelium with Opegan or Viscoat before fluid-air exchange largely prevents dry air damage to the endothelium. Infusion of humidified air further protects corneal endothelium during fluid-air exchange in aphakic rabbit eyes.

Topics: Actins; Air; Animals; Chondroitin; Chondroitin Sulfates; Desiccation; Drug Combinations; Endothelium, Corneal; Eye Injuries; Fluoresceins; Humidity; Hyaluronic Acid; Lens, Crystalline; Microscopy, Electron, Scanning; Permeability; Rabbits; Vitrectomy

To determine whether viscoelastic materials effectively protect the corneal endothelium from air bubbles.. Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.. Human eye-bank and rabbit eyes had a standardized phacoemulsification procedure with or without viscoelastic material (Healon [sodium hyaluronate 1.0%], Healon GV [sodium hyaluronate 1.4%], or Viscoat [chondroitin sulfate 4.0%-sodium hyaluronate 3.0%]). The integrity of the endothelium was examined after the procedure with F-actin staining and scanning electron microscopy. Rabbit eyes with and without viscoelastic material (Healon or Viscoat) had a standardized irrigation/aspiration (I/A) procedure. The mucinous layer of the endothelium was examined after the procedure with transmission electron microscopy.. In the phacoemulsification experiment without viscoelastic material, with Healon, and with Healon GV, the endothelium of human and rabbit corneas had many areas of cell loss in a pattern consistent with air-bubble damage. With Viscoat, endothelial cells remained intact. In the I/A experiment, the mucinous layer of Viscoat-exposed rabbit endothelium appeared thinner. In the same experiments without viscoelastic material or with Healon, the mucinous layer of the endothelium appeared normal.. Viscoat effectively protected the endothelium from air-bubble damage. Viscoat appears to protect the endothelium by acting as a physical barrier. Its adherence is probably related to the way it interacts with the mucinous layer of the endothelium.

Topics: Actins; Adolescent; Adult; Air; Animals; Child; Chondroitin; Chondroitin Sulfates; Drug Combinations; Endothelium, Corneal; Eye Injuries; Humans; Hyaluronic Acid; Microscopy, Electron, Scanning; Middle Aged; Phacoemulsification; Rabbits

The authors' study of the viscosities of various concentrations of sodium hyaluronate, chondroitin sulfate, and methylcellulose revealed that sodium hyaluronate and methylcellulose are pseudoplastic fluids in contrast to chondroitin sulfate, which is a Newtonian fluid. Pseudoplastic fluids are ideal for maintaining the anterior chamber, since they are more viscous at rest. Intermediate viscosity preparations of these three agents used as a thin endothelial coating gave excellent protection from intraocular lens abrasion. A highly viscous agent, eg, sodium hyaluronate 1%, in a thin layer produced extensive endothelial cell damage because it transmitted excessive shear force to the endothelium. A highly viscous agent, sodium hyaluronate 1% in a thick layer produced a physical barrier to compression with little endothelial damage. A low-viscosity agent, balanced salt solution provided insufficient protection against intraocular lens abrasion.

Topics: Animals; Cattle; Chemical Phenomena; Chemistry; Chondroitin; Chondroitin Sulfates; Cornea; Eye Injuries; Hyaluronic Acid; Hydrogen-Ion Concentration; Lenses, Intraocular; Methylcellulose; Viscosity

Topics: Academic Dissertations as Topic; Animals; Biochemical Phenomena; Biochemistry; Cataract; Chondroitin; Colloids; Dogs; Eye Injuries; Fundus Oculi; Gels; Heparin; Hyaluronic Acid; Injections; Ion Exchange; Ion Exchange Resins; Iron; Lens, Crystalline; Models, Biological; Photography; Polysaccharides; Rabbits; Retina; Retinal Detachment; Staining and Labeling; Sulfates; Sulfonic Acids; Tissue Adhesions; Uronic Acids; Vitreous Body