Study type: Medical/biological study (experimental study)

Acute ocular injuries caused by 60-GHz millimeter-wave exposure. med./bio.

Published in: Health Phys 2009; 97 (3): 212-218

Aim of study (acc. to author)

The authors have developed an acute ocular injury model and they used this model to examine the clinical course of millimeter wave-induced damages (examination until seven weeks after exposure). They also determined the experimental conditions leading to reproducible induction of ocular injuries caused by millimeter wave exposure.

Background/further details

40 rabbits 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).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 60 GHz
Exposure duration: continuous for 30 min
Exposure 2: 60 GHz
Exposure duration: continuous for 6 min
Exposure 3: 60 GHz
Exposure duration: continuous for 6 min

Exposure 1

Main characteristics
Frequency 60 GHz
Type
Exposure duration continuous for 30 min
Exposure setup
Exposure source
Setup horn antenna with a diameter of 15.5 mm placed 10 mm from the corneal apex; rabbit fixed in a holder; eyelids kept open with surgical tape
Parameters
Measurand Value Type Method Mass Remarks
power density 475 mW/cm² - - - -

Exposure 2

Main characteristics
Frequency 60 GHz
Type
Exposure duration continuous for 6 min
Exposure setup
Exposure source
Setup antenna with a diameter of 6 mm and 150 mm focal point; rabbit fixed in a holder; eyelids kept open with surgical tape
Parameters
Measurand Value Type Method Mass Remarks
power density 1.898 mW/cm² - - - -

Exposure 3

Main characteristics
Frequency 60 GHz
Type
Exposure duration continuous for 6 min
Exposure setup
Exposure source
Setup antenna with a diameter of 9 mm and 250 mm focal point; rabbit fixed in a holder; eyelids kept open with surgical tape
Parameters
Measurand Value Type Method Mass Remarks
power density 1.898 mW/cm² - - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • before exposure
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

The three antennas caused varying damages to the eyelids or eyeglobes. They all caused thermal burns to the eyelids that eventually affected the degree of intraocular injury. The most reproducible injuries without concurrent eyelid edema and corneal desiccation (that also can cause corneal epithelium damage) were achieved using the phi6 lens antenna: exposure for six minutes led to an elevation of the corneal surface temperature (reaching 54.2 +/- 0.9°C) plus corneal edema and epithelial cell loss. Furthermore, mitotic cells appeared in the pupillary area of the eye lens epithelium. Anterior uveitis also occurred resulting in acute miosis, an increase in flares (as marker for ocular inflammation), and iris vasodilation or vessel leakage.
These data 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.

Study character:

Study funded by

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