title: Corneal minimal visible lesion thresholds for 2.0 microm laser radiation.
abstract: To support refinement of the ANSI Maximum Permissible Exposure safety limits, a series of experiments were conducted in vivo on Dutch Belted rabbit corneas to determine corneal minimum visible lesion thresholds for 2.0 microm continuous-wave laser irradiation. Single pulse radiant exposures were made at specified pulse durations of 0.1, 0.25, 0.5, 1.0, 2.0, and 4.0 s for spot 1/e(2) diameters of 1.17 mm and 4.02 mm. Threshold lesions were defined as the presence of a superficial surface whitening one hour after irradiation. Temperature measurements indicated that threshold peak temperatures were dependent on spot size and exposure duration. The exposure duration dependence of threshold average radiant exposure was described by an empirical power law equation: threshold radiant exposure[J/cm(2)]=a x exposure duration[s](b).
authors.affiliation: Biomedical Engineering Laser Laboratory, The University of Texas at Austin, Austin, Texas 78712, USA. chenbo@mail.utexas.edu
authors.forename: Bo
authors.initials: B
authors.lastname: Chen
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Oliver
authors.forename: Soumak
authors.initials: S
authors.lastname: Dutta
authors.forename: Grady H
authors.initials: GH
authors.lastname: Rylander
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Thomsen
authors.forename: Ashley J
authors.initials: AJ
authors.lastname: Welch
mesh_terms: D000818:Animals; D003315:Cornea / Q000473:pathology*; D065306:Corneal Injuries; D004307:Dose-Response Relationship, Radiation; D005131:Eye Injuries / Q000209:etiology* / Q000473:pathology*; D007834:Lasers / Q000009:adverse effects*; D011817:Rabbits; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000209:etiology* / Q000473:pathology*