title: Mid-infrared laser ablation of the cornea: a comparative study.
abstract: The ablation thresholds and patterns of collateral damage in cornea produced by Er:YAG (2.94 microns) and Er:YSGG (2.79 microns) lasers were measured. Two different pulse durations, 200 microseconds (normal spiking mode) and 100 ns (Q-switched mode), were used at both wavelengths. In the normal spiking mode, damage zones of 16 +/- 2 microns and 39 +/- 7 microns and ablation thresholds of 250 +/- 20 mJ/cm2 and 420 +/- 35 mJ/cm2 were measured at 2.94 microns and 2.79 microns, respectively. In the Q-switched mode, damage zones of 4 +/- 2 microns and ablation thresholds of 150 +/- 10 mJ/cm2 were found irrespective of the laser used. The similarity between the results using the Er:YAG and Er:YSGG lasers in the Q-switched mode suggest that either laser can be used with equal effectiveness for corneal trephination.
authors.affiliation: Opthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami School of Medicine, Florida 33136.
authors.forename: Q
authors.initials: Q
authors.lastname: Ren
authors.forename: V
authors.initials: V
authors.lastname: Venugopalan
authors.forename: K
authors.initials: K
authors.lastname: Schomacker
authors.forename: T F
authors.initials: TF
authors.lastname: Deutsch
authors.forename: T J
authors.initials: TJ
authors.lastname: Flotte
authors.forename: C A
authors.initials: CA
authors.lastname: Puliafito
authors.forename: R
authors.initials: R
authors.lastname: Birngruber
mesh_terms: D000818:Animals; D002417:Cattle; D003315:Cornea / Q000473:pathology / Q000601:surgery*; D008028:Light Coagulation / Q000379:methods*