| Autor: |
Lizzi, F. L., Packer, A., Coleman, D. J. |
| Zdroj: |
Journal of the Acoustical Society of America; 1976, Vol. 59 Issue S1, pS59-S60, 2p |
| Abstrakt: |
Animal experimentation has been performed to study the effects of high-intensity, high-frequency (9.8 MHz) ultrasound on tissues of the eye. Several sets of rabbits have been exposed to examine alterations of the cornea, lens, retina, and choroid. Lenticular damage appeared first as haze cataracts observable with slit-lamp techniques. These were found to remain unchanged over observation periods as long as four months. Larger exposure levels resulted in the formation of totally opaque cataracts within the hazed lens segment. The appearance of haze together with their threshold exposure levels is consistent with thermally induced damage. Threshold curves resemble those predicted for thermal lesions in brain tissue. The shortest exposure time resulting in cataract formation was 35 msec. Irreversible corneal damage could also be produced after short exposures (100 msec). Corneal lesions appeared on slit-lamp examination as spherical opacities centrally situated within the corneal stroma. Chorio-retinal lesions were produced via trans-scleral insonification. Visible changes in the choroid are clearly observed during high-intensity insonification of albino rabbits. Transitory and permanent changes in the choroid were produced. Alterations in the overlying retina became visible within approximately one day subsequent to insonification. [Work supported by NIH.] [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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