Transient changes in the transmission of a 355 nm probe pulse through corneal tissue during 193 nm ArF laser ablation have been examined. A significant decrease in collimated transmission of the probe beam was observed for time delays between 10 ns and 1 ms after the 193 nm laser pulse. At 10 ns del
Transmission of corneal collagen during arf excimer laser ablation
β Scribed by M. N. Ediger; G. H. Pettit; R. P. Weiblinger; C. H. Chen
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 667 KB
- Volume
- 13
- Category
- Article
- ISSN
- 0196-8092
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β¦ Synopsis
The time-resolved transmission of collagen films and 10-pm sections of bovine cornea during ArF laser ablation has been investigated. The film studies were performed on thin layers of extracted bovine corneal collagen, the principal chromophore in 193 nm photoablation. Transmission measurements were made on both dry and water-saturated films to assess the sensitivity of the ablation process to hydration. Distinct transient optical changes were observed in both fully desiccated and rehydrated films. Dehydrated films exhibit rapid reduction in fdm absorption over the time-course of the ablating laser pulse, presumably due to chromophore bleaching or annihilation. In contrast, rehydrated films demonstrate a short-lived enhancement of the attenuation. In either case, a single ablative laser pulse increased the long-term transmission of the film, although this increase was a factor of five greater for dehydrated films than for rehydrated samples. Results obtained from corneal tissue sections were essentially identical to those derived from hydrated collagen films.
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