Acute ocular injuries caused by 60-Ghz millimeter-wave exposure.
The goal of this study was to examine the clinical course of 60-GHz millimeter-wave induced damages to the rabbit eye and to report experimental conditions that allow reproducible induction of these injuries. The eyes of pigmented rabbits (total number was 40) were irradiated with 60-GHz millimeter-waves using either a horn antenna or one of two lens antennas (6 and 9 mm diameter; phi6, phi9) Morphological changes were assessed by slit-lamp microscopy. Additional assessments included corneal fluorescein staining, iris fluorescein angiography, and lens epithelium light microscopy. Under the standardized eye-antenna positioning, the three antennas caused varying damages to the eyelids or eyeglobes. The most reproducible injuries without concurrent eyelid edema and corneal desiccation were achieved using the phi6 lens antenna: irradiation for 6 min led to an elevation of the corneal surface temperature (reaching 54.2 +/- 0.9 degrees C) plus corneal edema and epithelial cell loss. Furthermore, mitotic cells appeared in the pupillary area of the lens epithelium. Anterior uveitis also occurred resulting in acute miosis (from 6.6 +/- 1.4 to 2.2 +/- 1.4 mm), an increase in flares (from 6.7 +/- 0.9 to 334.3 +/- 130.8 photons per second), and iris vasodilation or vessel leakage. These findings indicate that the three types of millimeter-wave antennas can cause thermal injuries of varying types and levels. The thermal effects induced by millimeter-waves can apparently penetrate below the surface of the eye.
Kojima
Masami
M
Division of Vision Research for Environmental Health, Medical Research Institute, Kanazawa Medical University, 1-1, Daigaku, Uchinada-machi, Ishikawa, 920-0293, Japan. m-kojima@kanazawa-med.ac.jp
Hanazawa
Masahiro
M
Yamashiro
Yoko
Y
Sasaki
Hiroshi
H
Watanabe
Soichi
S
Taki
Masao
M
Suzuki
Yukihisa
Y
Hirata
Akimasa
A
Kamimura
Yoshitsugu
Y
Sasaki
Kazuyuki
K
D000208:Acute Disease; D000818:Animals; D002056:Burns / Q000209:etiology / Q000473:pathology; D003318:Corneal Opacity / Q000209:etiology / Q000473:pathology; D004195:Disease Models, Animal; D004574:Electromagnetic Fields / Q000009:adverse effects*; D005131:Eye Injuries / Q000209:etiology* / Q000473:pathology; D007498:Iris / Q000098:blood supply / Q000293:injuries; D008297:Male; D015877:Miosis / Q000209:etiology / Q000473:pathology; D011817:Rabbits; D011829:Radiation Dosage; D011833:Radiation Injuries, Experimental / Q000209:etiology* / Q000473:pathology; D015203:Reproducibility of Results; D014664:Vasodilation / Q000528:radiation effects