title: CO2, excimer and erbium:YAG laser in deep sclerectomy.
abstract: OBJECTIVE
  Deep sclerectomy is a non-penetrating filtering procedure that is not generally accepted, as tissue dissection is difficult and varying success rates have been reported. The purpose of the present study was to compare the use of CO2, excimer and erbium:YAG lasers in dissection of the deep corneoscleral lamella.
  
  
  METHODS
  In enucleated porcine eyes a superficial lamellar scleral flap of 5 x 5 mm was surgically dissected. The deep lamella was removed using a pulsed erbium:YAG, a CO2 or an excimer laser (10 eyes/group). All eyes were analysed histologically and 3 in each group by scanning electron microscopy (SEM).
  
  
  RESULTS
  It is feasible to ablate the deep corneoscleral lamella with the CO2, excimer and erbium:YAG lasers without perforating the anterior chamber. The following histology and SEM showed a smoother surface after dissection with the CO2 and excimer lasers compared to the erbium:YAG laser. There was no thermal damage after excimer laser treatment, compared to a damage zone of 10-30 mum using the erbium laser and one of 70-100 microm with the CO2 laser.
  
  
  CONCLUSIONS
  Excimer,erbium:YAG and CO2 lasers allow the microsurgical dissection of the deep lamella. The excimer and CO2 lasers achieve a more regular and smoother tissue surface. The excimer laser has the advantage to dissect without thermal tissue damage.
authors.affiliation: Department of Ophthalmology, Julius Maximilian University, Wurzburg, Germany. klink_t@klinik.uni-wuerzburg.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Klink
authors.forename: Gunther
authors.initials: G
authors.lastname: Schlunck
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Lieb
authors.forename: Janine
authors.initials: J
authors.lastname: Klink
authors.forename: Franz
authors.initials: F
authors.lastname: Grehn
mesh_terms: D000818:Animals; D002245:Carbon Dioxide; D003315:Cornea / Q000601:surgery* / Q000648:ultrastructure; D004210:Dissection; D004867:Equipment Design; D066298:In Vitro Techniques; D007498:Iris / Q000473:pathology; D053685:Laser Therapy / Q000295:instrumentation / Q000379:methods*; D054018:Lasers, Excimer; D053844:Lasers, Solid-State; D008855:Microscopy, Electron, Scanning; D008866:Microsurgery; D011184:Postoperative Period; D012590:Sclera / Q000601:surgery* / Q000648:ultrastructure; D013552:Swine
chemical_list: D002245:Carbon Dioxide