Theory concerning the ablation of corneal tissue with large-area, 193-nm excimer laser beams.

Excimer laser beams (193 nm) of uniform fluence were studied to find out why they produce corneal ablations deeper at the edge than the center. Ablation depth profiles were taken of porcine corneas, including five dehydrated samples. Hydrated corneas and polymethyl methacrylate were ablated with and without central masks.

Fluorescence-guided laser removal of chemically damaged cornea.

Purpose: To correlate the observed fluorescence spectrum with the depth of ablation during 193 nm argon-fluoride excimer laser ablation of chemically damaged corneas.

Setting: Laser facility, Cedars-Sinai Medical Center, Los Angeles, California, USA.

Methods: Three cadaver New Zealand white rabbit corneas were exposed to 1 N hydrogen chloride for 10 seconds.