LASER-INDUCED ACOUSTIC TRANSIENTS IN MAMMALIAN EYE

Acoustic transients resulting from the absorption of normal mode and Q switched laser pulses in the mammalian eye have been implicated in damage to retinal tissue. A theoretical analysis indicated that acoustic transients with durations of the same order as the laser pulse (e.g., 100 msec for a Q switched pulse) and amplitudes of greater than 100 atm could be produced in model systems that simulate the retina. Piezoelectric transducers and a schlieren optical system were used to verify experimentally the theoretical predictions. By the use of these devices, studies were made of the production of laser induced acoustic transients in the rabbit eye. An 18 mJ Q switched ruby laser pulse produced acoustic transients with amplitudes of 1000 atm in the immediate vicinity of the site of absorption, a 750 μ diam spot on the retina. Normal mode laser pulses of the same energy but with durations of 0.5 msec produced a train of pulses with amplitudes 500 1000 times less than the Q switched pulse. The biological significance of these findings is discussed. © 1969, Acoustical Society of America. All rights reserved.