Solid-State Ultraviolet-Laser (213 Nm) Ablation Of The Cornea And Synthetic Collagen Lenticules
Collagen; Excimer Lasers; Nonlinear Optical Crystals; Refractive Surgery; Excimer Laser; Keratectomy; Eye; Surgery
We used a Q-switched Nd:YAG laser with non-linear optical crystals to produce the 5th (213 nm) and the 4th (266 nm) harmonic frequencies. Using these two wavelengths, we ablated fresh porcine corneas and type I collagen synthetic epikeratoplasty lenticules. For the 213-nm ablation, radiant exposure was 1.3 J/cm2. The ablation rate was 0.23-mu-m per pulse for the epikeratoplasty lenticules. We examined all tissues with light microscopy, transmission electron microscopy, and scanning electron microscopy. Histology for the 213-nm ablation showed a clean ablation crater with minimal collagen lamellae disruption and a damage zone less than 1-mu-m. In comparison, the 266 nm radiation showed more charring at the edges with a damage zone approximately 25-mu-m deep with disruption of the stromal lamella. Our results show that this solid state UV laser is a potential alternative to the excimer laser for cornea surgery.
Lasers in Surgery and Medicine
Gailitis, R. P.; Ren, Q. S.; Thompson, K. P.; Lin, J. T.; and Waring, G. O., "Solid-State Ultraviolet-Laser (213 Nm) Ablation Of The Cornea And Synthetic Collagen Lenticules" (1991). Faculty Bibliography. 2086.