EXPERIMENTAL, ULTRASONICALLY INDUCED LESIONS IN RETINA, CHOROID, AND SCLERA

Google Scholar
  • 1 January 1978
    • journal article
    • research article
    • Vol. 17  (4) , 350-360
Abstract
Lesions of the retina, choroid and sclera were created in the proptosed eye of the rabbit with the use of focused ultrasound at 9.8 MHz. Exposure levels greatly exceeding those encountered in diagnostic systems were required. Histological examination of selected tissue samples, analysis of lesion-producing exposures and lesion size variations suggested that thermal mechanisms were the principal cause of permanent tissue alterations. Subthreshold lesions, which consisted of transitory effects, were observed. Threshold lesions first manifested transitory effects followed by permanent alterations which appeared within 24 h. Suprathreshold lesions were evidenced by the immediate appearance of a highly blanced area with an overlying edema and occasional hemorrhage, appearing within 24 h. The edema in these cases was resorbed within a few days, leaving behind a permanently blanched region. The threshold curve developed from these data was similar in shape to the threshold curve for light-induced lesions created with a commensurate focal spot.