Excimer laser ablation of the lens
T. M. Nanevicz, M. R. Prince, A. A. Gawande and C. A. Puliafito
Ablation of the bovine crystalline lens was studied using radiation from an
excimer laser at four ultraviolet wave lengths as follows: 193 nm (argon
fluoride), 248 nm (krypton fluoride), 308 nm (xenon chloride), and 351 nm
(xenon fluoride). The ablation process was quantitated by measuring mass
ablated with an electronic balance, and characterized by examining ablation
craters with scanning electron microscopy. The highest ablation rate was
observed at 248 nm with lower rates at 193 and 308 nm. No ablation was
observed at 351 nm. Scanning electron microscopy revealed the smoothest
craters at 193 nm while at 248 nm there was vacuolization in the crater
walls and greater disruption of surrounding tissue. The craters made at 308
nm did not have as smooth a contour as the 193-nm lesions. The spectral
absorbance of the bovine lens was calculated at the wavelengths used for
ablation and correlated with ablation rates and thresholds. High
peak-power, pulsed ultraviolet laser radiation may have a role in surgical
removal of the lens.
