Accession Number:

ADA058449

Title:

Mechanisms of Retinal Damage from Chronic Laser Radiation. Thresholds and Mechanisms.

Descriptive Note:

Annual rept. no. 4. 1 Nov 76-31 Oct 77,

Corporate Author:

LOUISVILLE UNIV KY DEPT OF OPHTHALMOLOGY

Report Date:

1977-08-01

Pagination or Media Count:

43.0

Abstract:

The effect upon the retina of exposure to large fields of bright visible light has been evaluated. The thresholds for permanent retinal damage for four hour exposures in rhesus monkeys have been established for white light, and laser lines of 514.5 nm, 488 nm, 457.9 nm, and 590 nm. The damage has been evaluated by ophthalmoscopy, electroretinography and light and electron microscopy. The shortest wavelength light 457.9 nm is more effective in causing damage, particularly histological damage, which is spread throughout the fundus and throughout the retina layers. Functional damage shown by the electroretinogram follows a different action spectrum 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 solely upon the visual pigment and the pigment epithelium. Thresholds of permanent damage appear to be within one or two log units of light levels encountered in the normal visual environment. Newer data suggest that this damage is additive. Daily one hour exposures for four days produce damage equivalent to a single four hour exposure at the same retinal irradiance. Author

Subject Categories:

  • Lasers and Masers

Distribution Statement:

APPROVED FOR PUBLIC RELEASE