title: CO₂ laser welding of corneal cuts with albumin solder using radiometric temperature control.
abstract: OBJECTIVE
  To examine the efficacy and reproducibility of CO₂ laser soldering of corneal cuts using real-time infrared fiber-optic radiometric control of tissue temperature in bovine eyes (in vitro) and to evaluate the duration of this procedure in rabbit eyes (in vivo).
  
  
  METHODS
  In vitro experiment: a 6-mm central perforating cut was induced in 40 fresh bovine eyes and sealed with a CO₂ laser, with or without albumin soldering, following placement of a single approximating nylon suture. A fiber-optic radiometric temperature control system for the CO₂ laser was used. Leaking pressure and histological findings were analyzed and compared between groups. In vivo experiment: following creation of a central perforation, 6 rabbit eyes were treated with a CO₂ laser with albumin solder and 6 rabbit eyes were treated with 10-0 nylon sutures. The amount of time needed for completion of the procedures was compared.
  
  
  RESULTS
  In vitro experiment: effective sealing was achieved by CO₂ laser soldering. Mean (± SD) leaking pressure was 109 ± 30 mm Hg in the bovine corneas treated by the laser with albumin solder compared to 51 ± 7 mm Hg in the sutured control eyes (n = 10 each; p < 0.001). Mean leaking pressures were much lower in the corneal cuts sealed only with the laser without albumin solder (48 ± 12 mm Hg) and in the cuts sealed only with albumin without laser welding (6.3 ± 4 mm Hg) than in the cuts treated with laser welding and albumin solder. In vivo experiment: mean surgical time was 140 ± 17 s in the laser-treated rabbits compared to 330 ± 30 s in the sutured controls (n = 6; p < 0.001). A histopathological study of the rabbit corneas 1 day after laser soldering revealed sealed corneal edges with a small gap bridged by coagulated albumin. The inflammatory reaction was minimal in contrast to the sutured controls. No thermal damage was detected at the wound edges.
  
  
  CONCLUSIONS
  CO₂ laser soldering combined with the fiber-optic radiometer is an effective, reliable, and rapid tool for the closure of corneal wounds, and holds advantages over conventional suturing in terms of leaking pressure and surgical time.
authors.affiliation: Department of Ophthalmology, Hadassah Medical Center and the Hebrew University, Jerusalem, Israel.
authors.forename: Eyal
authors.initials: E
authors.lastname: Strassmann
authors.forename: Eitan
authors.initials: E
authors.lastname: Livny
authors.forename: Nino
authors.initials: N
authors.lastname: Loya
authors.forename: Noam
authors.initials: N
authors.lastname: Kariv
authors.forename: Avi
authors.initials: A
authors.lastname: Ravid
authors.forename: Abraham
authors.initials: A
authors.lastname: Katzir
authors.forename: Dan D
authors.initials: DD
authors.lastname: Gaton
mesh_terms: D000818:Animals; D002245:Carbon Dioxide; D002417:Cattle; D003316:Corneal Diseases / Q000601:surgery*; D065306:Corneal Injuries; D004195:Disease Models, Animal; D005336:Fiber Optic Technology; D006358:Hot Temperature; D054020:Lasers, Gas / Q000627:therapeutic use*; D011874:Radiometry / Q000379:methods; D015203:Reproducibility of Results; D012709:Serum Albumin / Q000008:administration & dosage; D013536:Suture Techniques; D013821:Thermometers
chemical_list: D012709:Serum Albumin; D002245:Carbon Dioxide