Temperature Rise in Fundus Exposed to Laser Radiation.
Abstract
Temperature measurements were made in the eyes of living rhesus monkeys with 20 micrometers copper-nickel thermocouples. The temperature rise at the center of 100 micrometers - 200 micrometers (half-power diameter) ophthalmoscopically visible lesions was used as a measurement of the threshold of damage to the eye. The appearance of a minimal visible lesion 5 minutes postexposure was the criterion for damage. Threshold temperature rise was measured for 0.1-sec, 1-sec, and 10-sec exposures to an argon (4880 A) laser. Thresholds were acquired for both macular and paramacular (temporal) exposure sites. The average macular threshold temperatures at 0.1 sec, 1 sec, and 10 sec were 29.8 C, 24.4 C, and 20.0 C respectively. For paramacular insertions the average temperature rise above ambient (37 C) was 39.0 C for a 0.1-sec exposure, 28.8 C for a 1-sec exposure, and 24.7 C for a 10-sec exposure. The temperature rise was predicted by a finite differences model solution to the heat conduction equation. The model was 10%-20% lower than the experimentally measured temperature for a 10-sec exposure and approximately 10% higher for a 0.1-sec exposure. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1975
- Accession Number
- ADA014819
Entities
People
- Ashley J. Welch
- Clarence P. Cain
- Leslie A. Priebe
Organizations
- University of Texas at Austin