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U.S. Department of Energy
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Retinal-hemorrhage thresholds for Q-switched neodymium-YAG laser exposures

Technical Report ·
OSTI ID:6984803
Thresholds for retinal vitreal and contained hemorrhages were determined for 1064-nm laser light at 30-ns and 4-ns pulsewidths. Rhesus monkeys received graded exposures from a neodymium-YAG laser onto either the macular or extramacular region of the retina. Contained hemorrhages appeared as concentric-ring structures with white punctuate centers. The vitreal hemorrhage was characterized by the presence of choroidal blood in the vitreal chamber at the exposure site. The 30-ns contained-hemorrhage threshold (ED50) was 1.7 mJ on the macula and 2.1 mJ for an extramacular exposure. The 30-ns vitreal-hemorrhage macular threshold was 2.3 mJ, and the extramacular threshold was 6.6 Mj. The threshold for the 4-ns pulse widths to produce a hemorrhage (vitreal or contained) on the retina (macula or extramacular) was 340 uJ.
Research Organization:
Technology, Inc., San Antonio, TX (USA). Life Sciences Div.
OSTI ID:
6984803
Report Number(s):
AD-A-171977/2/XAB
Country of Publication:
United States
Language:
English