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Proceedings Paper

Corneal effects produced by IR laser radiation
Author(s): Richard A. Farrell; C. Brent Bargeron; Russell L. McCally; W. Richard Green
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Paper Abstract

Infrared radiation from a CO2 laser at a wavelength of 10.6 im is strongly absorbed by the cornea. Indeed, 99% is absorbed within the first 50 itm of tear film and epithelium. This energy is rapidly converted to heat that initially is concentrated in the volume of absorption and subsequently is conducted to deeper layers of the cornea and beyond. Consequently, various layers of the cornea can sustain thermal damage, depending on the exposure conditions. In this review we summarize very briefly our past work on: epithelial damage thresholds for single- and multiple-pulse exposures having individual pulse durations between 1 ms and 10 s12; endothelial damage thresholds and endothelial temperature histories34; and damage thresholds for stromal cells.5 For very short duration pulses that have extremely high peak irradiance, the possibility for acoustic as well as thermal damage exists. Here we give a more extensive report of new epithelial damage thresholds for single- and multiple-pulse exposures with an individual pulse duration of 80 ns. We note that material is ejected from the corneal surface at near-threshold exposures. This observation is used in conjunction with lesion histology and temperature computations to discuss possible damage mechanisms.

Paper Details

Date Published: 1 July 1990
PDF: 12 pages
Proc. SPIE 1207, Laser Safety, Eyesafe Laser Systems, and Laser Eye Protection, (1 July 1990); doi: 10.1117/12.17831
Show Author Affiliations
Richard A. Farrell, Johns Hopkins Univ. (United States)
C. Brent Bargeron, Johns Hopkins Univ. (United States)
Russell L. McCally, Johns Hopkins Univ. (United States)
W. Richard Green, Wilmer Institute of the Johns Hopkins Medical Institutions (United States)


Published in SPIE Proceedings Vol. 1207:
Laser Safety, Eyesafe Laser Systems, and Laser Eye Protection
Penelope K. Bryan; David H. Sliney, Editor(s)

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