Accession Number:

ADA379774

Title:

Study of Short-Pulsed Laser Retinal Injury Mechanisms By Time-Resolved Imaging of Photomechanical Transients in RPE

Descriptive Note:

Final rept. 1 Jul 1996-30 Jun 1999

Corporate Author:

MASSACHUSETTS GENERAL HOSPITAL BOSTON WELLMAN LABS OF PHOTOMEDICINE

Personal Author(s):

• Lin, Charles P.

Report Date:

2000-05-14

Pagination or Media Count:

9.0

Abstract:

We studied RPE cell damage mechanism for laser duration from 100 femtosec to 5 microsec, and we have investigated the dependence of threshold fluence for cell damage on the laser spot size on the RPE. These results will be summarized in the report. Our current method for studying call damage mechanism in the RPE is stroboscopic time resolved microscopy, which allows us to image the transient microscopic bubble formation inside the RPE tissue ex vivo where the cells following pulse laser irradiation. This technique works well in RPE tissue ex vivo where the strobe light transilluminates the specimen. Since our ultimate goal is to detect the existence of these micobubbles in vivo, we have set up a stroboscopic imaging system in epi-illumination geometry. However, the image quality obtained in this way is inferior to that obtained by transillumination, most likely because of the strong angular dependence of the back-scattered light by the spherical bubbles. It is thus difficult to identify the extent of bubble formation at the RPE by this method.

Descriptors:

• *EYE SAFETY
• *LASER DAMAGE
• EPITHELIUM
• PULSED LASERS
• RETINA
• IRRADIATION
• STROBOSCOPES
• LASER SPOTS

Subject Categories:

• Medicine and Medical Research
• Lasers and Masers

Distribution Statement:

APPROVED FOR PUBLIC RELEASE