Mechanisms of retinal damage from chronic laser radiation. Annual report, 1 September 1973-31 October 1976

Technical Report · Mon Nov 01 04:00:00 EST 1976

OSTI ID:7232460

Lawwill,; Crockett, S; Currier, G J

The effect upon the retina of exposure to large fields of bright visible light was evaluated. The thresholds for retinal damage for four-hour exposures in rhesus monkeys were established for white light, argon laser lines of 514.5 nm, 488 nm, and 457.9 nm, and for 590 nm light from a dye laser. The damage was evaluated by ophthalmoscopy, electroretinography, light, and electron microscopy. The 457.9-nm light is more effective in causing damage, particularly histological damage, which is spread throughout the fundus and throughout the retinal layers. Functional damage shown by the electroretinogram follows a different spectral sensitivity curve without the increased effect in the blue. There appears to be more than one mechanism for retinal damage in chronic light exposure, and at least one mechanism is not dependent upon the visual pigment or the pigment epithelium. Thresholds appear to be within one or two log units of light levels encountered in normal visual experience. The model here considers exposing most of the posterior pole to an even illumination of moderately bright light for a period of hours. Thermal damage caused by small spot laser burns and photocoagulation is not the object; rather it is shown. That not only is the threshold lower with blue light, but that the morphological changes are different from those previously described. Primary damage occurs in retinal layers thought of as transparent to the damaging wavelength.

• Research Organization: Louisville Univ., KY (USA). Dept. of Ophthalmology
• OSTI ID: 7232460
• Report Number(s): AD-A-172458/2/XAB
• Country of Publication: United States
• Language: English

Related Subjects

560400* -- Other Environmental Pollutant Effects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL TISSUES
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BODY
BODY AREAS
BRIGHTNESS
DAMAGE
DYE LASERS
ELECTROMAGNETIC RADIATION
ELECTRON MICROSCOPY
EPITHELIUM
EYES
FACE
HEAD
HISTOLOGY
LASER RADIATION
LASERS
LAYERS
LIQUID LASERS
MAMMALS
MICROSCOPY
NECROSIS
OPTICAL PROPERTIES
ORGANS
PATHOLOGICAL CHANGES
PHYSICAL PROPERTIES
PIGMENTS
RABBITS
RADIATION EFFECTS
RADIATIONS
RATS
RETINA
RODENTS
SENSE ORGANS
SENSITIVITY
SPECTRA
TISSUES
VERTEBRATES
VISIBILITY