Retinal damage thresholds from single-pulse laser exposures in the visible spectrum

Journal Article · Mon May 01 04:00:00 EDT 1989 · Health Phys.; (United States)

DOI:https://doi.org/10.1097/00004032-198905000-00006· OSTI ID:6020333

Courant, D; Court, L; Abadie, B; Brouillet, B

The risks of using lasers, particularly ocular hazards, have called for the definition of exposure limits. Our investigations involved the retinal effects of the laser beam in the visible spectrum and were directed toward verifying the limit values by defining the thresholds of retinal damage in experiments carried out on the rabbit and the monkey. The wavelengths emitted by the experimental set-ups were 593 and 532 nm, the pulse durations were 600 and 40 ns, and the retinal image diameter varied from approximately 30 to 570 microns. A direct ophthalmoscopic observation and a method using fluorescein angiography were employed to detect a pathologic change in the retina. The energy correlates of retinal lesions were statistically analyzed by a method of probit analysis. The results showed that determining funduscopic thresholds is chiefly a function of the investigation technique used and the delay in observation after the exposure. Our results obtained with fluorescein angiography extrapolated to the human eye support the exposure limit established for intrabeam viewing, but not for an extended source laser which corresponds to a probability of damage increasing with the retinal image diameter. The exposure limit related to the experimental retinal spot size of 285 and 570 microns corresponds to damage probabilities of 7% and 32%, respectively.

• Research Organization: Centre d'Etudes Nucleaires, Fontenay-aux-Roses (France)
• OSTI ID: 6020333
• Journal Information: Health Phys.; (United States), Journal Name: Health Phys.; (United States) Vol. 56:5; ISSN HLTPA
• Country of Publication: United States
• Language: English

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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOLOGICAL EFFECTS
BODY
BODY AREAS
ELECTROMAGNETIC RADIATION
EYES
FACE
HEAD
LASER RADIATION
LASERS
MAMMALS
MAXIMUM PERMISSIBLE EXPOSURE
MONKEYS
ORGANS
PATHOLOGICAL CHANGES
PRIMATES
RABBITS
RADIATIONS
RETINA
SAFETY STANDARDS
SENSE ORGANS
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WAVELENGTHS