Localized current field hyperthermia: effect on normal ocular tissue.
Using a 500 kHz radiofrequency electromagnetic heating system, the effects of localized current field hyperthermia in normal rabbit eyes were examined. A specially designed scleral plaque placed on normal rabbit eyes was heated to temperatures of 43 degrees C, 45 degrees C, and 47 degrees C for a period of 45 min. The effects of hyperthermia were monitored by clinical examination, fluorescein angiography, electroretinography and histopathology. A graded effect with increasing temperature was found at the lower temperature, and it was confined to the treatment field. At 47 degrees C the electroretinogram was extinguished due to diffuse photoreceptor damage outside the treatment field, as demonstrated by histopathology and electron microscopy. This study indicates that hyperthermia at 45 degrees C for 45 min is the maximum allowable temperature without causing diffuse retinal damage in the normal rabbit eye.
Liggett
P E
PE
Department of Opthalmology, University of Southern California School of Medicine, Los Angeles.
Pince
K J
KJ
Astrahan
M
M
Rao
N
N
Petrovich
Z
Z
D000818:Animals; D005131:Eye Injuries / Q000209:etiology* / Q000473:pathology; D006358:Hot Temperature / Q000009:adverse effects* / Q000627:therapeutic use; D006801:Humans; D008545:Melanoma / Q000628:therapy; D010786:Photoreceptor Cells / Q000293:injuries / Q000473:pathology; D011817:Rabbits; D014604:Uveal Neoplasms / Q000628:therapy