Accession Number : ADA295024

Title :   Ultrashort Pulse Laser Effects in the Primate Eye.

Descriptive Note : Interim rept. Mar 93-Jun 94,

Corporate Author : ANALYTIC SCIENCES CORP SAN ANTONIO TX

Personal Author(s) : Cain, Clarence P. ; Noojin, Gary D. ; Stolarski, David J. ; Toth, Cynthia A. ; DiCarlo, Cheryl D.

PDF Url : ADA295024

Report Date : NOV 1994

Pagination or Media Count : 121

Abstract : Minimum visible lesion (MVL) threshold measurements at the retina for rhesus monkey eyes are reported for femtosecond, picosecond, and nanosecond single laser pulses using visible wavelengths. Estimates of the dose causing 50% probability for damage (ED50) are calculated for 1-hour and 24-hours postexposure as well as the 95% fiducial intervals for ED. The ED values are found to be dependent on both wavelength and pulsewidth, and for a single wavelength are, in general, lower for short pulsewidths, with the exception of values at the shortest pulsewidth of 90 fs at 580 nm. At 90 fs the ED(50) dosages were noted to increase slightly when compared with the 3-ps and 600-fs values, all three delivered at 580-nm wavelength. The 4-ns ED(50) value was more than double the value at 60 ps delivered at 532-nm wavelength. Fluorescein angiography was accomplished at 1-hour and 24-hours postexposure and did not demonstrate lower threshold for damage, which has been the case for MVLs created with longer pulse duration (greater than 1 ns) or for rabbit eyes at the same pulse-widths as measured in our laboratory.

Descriptors :   *PULSED LASERS, *EYE, FREQUENCY, MEASUREMENT, THRESHOLD EFFECTS, LASER BEAMS, ESTIMATES, PULSE RATE, VISIBILITY, DOSAGE, RETINA, LASER SAFETY, PRIMATES, SHORT PULSES, LESIONS, RABBITS, RHESUS MONKEYS, EXPOSURE(PHYSIOLOGY).

Subject Categories : Anatomy and Physiology
      Stress Physiology
      Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE