Ultrasonic Hyperthermia for Ophthalmic Therapy

Absfrucct-A theoretical model was developed to compute the spatiotemporal features of temperature rises induced in ocular tissue during exposure to high-intensity focused ultrasound. The model incorporates damage integral evaluation to predict the Occurrence and dimensions of thermally induced lesions. Experimental data confirmed the accuracy of computed lesion dimensions for scleral and chorioretinal lesions. Computed results also are in agreement with measured threshold exposure levels needed to produce minimal chorioretinal lesions. The model is being improved to account for blood-flow cooling effects during longterm hyperthermia. Data were collected using this long-term mode on Greene’s melanoma implanted in the rabbit choroid, and these data indicate that tumor regression can be achieved at levels that are consistent with damage integral predictions.