These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Computer model to investigate the effect of eye movements on retinal heating during long-duration fixation on a laser source.
    Author: Lund BJ.
    Journal: J Biomed Opt; 2004; 9(5):1093-102. PubMed ID: 15447030.
    Abstract:
    A computer simulation called RHME (Retinal Heating in Moving Eye) is developed to simulate the heating pattern that occurs in the retina during a long-duration exposure to a continuous wave laser beam. The simulation takes into account eye movements that occur during a deliberate fixation. Due to the rapid (millisecond) thermal time scale for heating and cooling, only the area of the retina directly exposed to the laser sustains an increased temperature. Once the laser spot is removed from a particular location of the retina (because of eye movements) that location quickly cools. Points of the retina will therefore have a complex thermal history during a long-duration exposure. Simulation results for a minimal retinal spot size indicate that subjects staring at a helium-neon laser (lambda=632.8 nm) beam producing the small-source maximum permissible exposure (MPE) level corneal irradiance of 1 mW cm(-2) (>10-s exposure) will experience a maximum although transient temperature increase in the retina of less than 2 degrees C during a 50-s fixation trial. The large increase in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) and ANSI Z136.1 safety limits for a long-duration small-source exposure to visible continuous wave lasers that was adopted in 2000 therefore appears appropriate.
    [Abstract] [Full Text] [Related] [New Search]