title: Viscoelastic protection from endothelial damage by air bubbles.
abstract: OBJECTIVE
  To determine whether viscoelastic materials effectively protect the corneal endothelium from air bubbles.
  
  
  METHODS
  Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Institute of Vision Research, Department of Ophthalmology,Yonsei University, Seoul, South Korea. eungkkim@yumc.yonsei.ac.kr
authors.forename: Eung Kweon
authors.initials: EK
authors.lastname: Kim
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Cristol
authors.forename: Shin J
authors.initials: SJ
authors.lastname: Kang
authors.forename: Henry F
authors.initials: HF
authors.lastname: Edelhauser
authors.forename: Hyung Lae
authors.initials: HL
authors.lastname: Kim
authors.forename: Jae Bum
authors.initials: JB
authors.lastname: Lee
mesh_terms: D000199:Actins / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000388:Air; D000818:Animals; D002648:Child; D002807:Chondroitin / Q000627:therapeutic use*; D002809:Chondroitin Sulfates; D004338:Drug Combinations; D004728:Endothelium, Corneal / Q000293:injuries* / Q000378:metabolism / Q000648:ultrastructure; D005131:Eye Injuries / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D006801:Humans; D006820:Hyaluronic Acid / Q000627:therapeutic use*; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D018918:Phacoemulsification / Q000379:methods; D011817:Rabbits
chemical_list: D000199:Actins; D004338:Drug Combinations; C501944:chondroitin sulfate, sodium hyaluronate drug combination; D006820:Hyaluronic Acid; D002807:Chondroitin; D002809:Chondroitin Sulfates