Quantitative and ultrastructural studies of excimer laser ablation of the cornea at 193 and 248 nanometers
Excimer laser radiation at 193 nm and 248 nm was used to create linear etch perforations of enucleated calf corneas. The etch depth per pulse was determined for various exposures, and specimens were examined by light and transmission electron microscopy. Compared to 248 nm, excimer laser ablation at 193 nm was found to have a lower threshold for onset of ablation, less increase in etch depth per pulse at increasing fluences, and less structural alteration in adjacent cornea. For 193 nm, structural alterations were minimal, confined to an area less than 0.3 micron wide, and did not increase with increasing fluence. These studies suggest that clinical strategies for excimer laser refractive surgery will employ the 193-nm wavelength, with fluence chosen depending on surgical strategy. Ablation exposures above 600 mJ/cm2 at 193 nm may give the most repeatable etch depth.
- Research Organization:
- Massachusetts Eye and Ear Infirmary, Boston
- OSTI ID:
- 6119274
- Journal Information:
- Lasers Surg. Med.; (United States), Journal Name: Lasers Surg. Med.; (United States) Vol. 7:2; ISSN LSMED
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
560400* -- Other Environmental Pollutant Effects
62 RADIOLOGY AND NUCLEAR MEDICINE
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOLOGICAL EFFECTS
BODY
BODY AREAS
CALVES
CATTLE
CORNEA
DOMESTIC ANIMALS
DOSE-RESPONSE RELATIONSHIPS
ELECTROMAGNETIC RADIATION
ELECTRON MICROSCOPY
EYES
FACE
HEAD
LASER RADIATION
MAMMALS
MEDICINE
MICROSCOPY
MORPHOLOGICAL CHANGES
ORGANS
RADIATIONS
RUMINANTS
SENSE ORGANS
SURGERY
ULTRASTRUCTURAL CHANGES
VERTEBRATES
WAVELENGTHS