title: Safety of cornea and iris in ocular surgery with 355-nm lasers.
abstract: A recent study showed that 355-nm nanosecond lasers cut cornea with similar precision to infrared femtosecond lasers. However, use of ultraviolet wavelength requires precise assessment of ocular safety to determine the range of possible ophthalmic applications. In this study, the 355-nm nanosecond laser was evaluated for corneal and iris damage in rabbit, porcine, and human donor eyes as determined by minimum visible lesion (MVL) observation, live/dead staining of the endothelium, and apoptosis assay. Single-pulse damage to the iris was evaluated on porcine eyes using live/dead staining. In live rabbits, the cumulative median effective dose (ED50) for corneal damage was 231 J/cm2, as seen by lesion observation. Appearance of endothelial damage in live/dead staining or apoptosis occurred at higher radiant exposure of 287 J/cm2. On enucleated rabbit and porcine corneas, ED50 was 87 and 52 J/cm2, respectively, by MVL, and 241 and 160 J/cm2 for endothelial damage. In human eyes, ED50 for MVL was 110 J/cm2 and endothelial damage at 453 J/cm2. Single-pulse iris damage occurred at ED 50 of 208 mJ/cm2. These values determine the energy permitted for surgical patterns and can guide development of ophthalmic laser systems. Lower damage threshold in corneas of enucleated eyes versus live rabbits is noted for future safety evaluation.
authors.affiliation: Stanford University, Department of Applied Physics, 452 Lomita Mall, Stanford, California 94305, United States.
authors.forename: Jenny
authors.initials: J
authors.lastname: Wang
authors.affiliation: Stanford University, Department of Ophthalmology, 452 Lomita Mall, Stanford, California 94305, United StatescKonyang University, Kim's Eye Hospital, Department of Ophthalmology, 136 Yeongshin-ro, Youngdeungpo-gu, Seoul 150-034, Republic of Korea.
authors.forename: Jae Lim
authors.initials: JL
authors.lastname: Chung
authors.affiliation: Abbott Medical Optics, 1310 Moffett Park Drive, Sunnyvale, California 94089, United States.
authors.forename: Georg
authors.initials: G
authors.lastname: Schuele
authors.affiliation: Abbott Medical Optics, 1310 Moffett Park Drive, Sunnyvale, California 94089, United States.
authors.forename: Alexander
authors.initials: A
authors.lastname: Vankov
authors.affiliation: Stanford University, Department of Ophthalmology, 452 Lomita Mall, Stanford, California 94305, United States.
authors.forename: Roopa
authors.initials: R
authors.lastname: Dalal
authors.affiliation: Abbott Medical Optics, 1310 Moffett Park Drive, Sunnyvale, California 94089, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Wiltberger
authors.affiliation: Stanford University, Department of Ophthalmology, 452 Lomita Mall, Stanford, California 94305, United StateseStanford University, Hansen Experimental Physics Laboratory, 452 Lomita Mall, Stanford, California 94305, United States.
authors.forename: Daniel
authors.initials: D
authors.lastname: Palanker
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D002470:Cell Survival / Q000528:radiation effects; D003315:Cornea / Q000528:radiation effects*; D006801:Humans; D007498:Iris / Q000528:radiation effects*; D020731:Keratomileusis, Laser In Situ / Q000009:adverse effects / Q000295:instrumentation* / Q000592:standards; D007834:Lasers / Q000009:adverse effects* / Q000592:standards; D061214:Patient Safety; D011817:Rabbits; D013552:Swine