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| Ocular Effects The eye is potentially susceptible to RF radiation since its limited blood supply means that it cannot easily dissipate heat (IEGMP, 2000). In addition it does not have the same degree of bony protection that the brain receives from the skull. Studies
on the effect of RF exposure on animals have been largely negative,
despite the fact that most studies employed exposure levels greatly
in excess of that seen with mobile phones (Carpenter, 1979; Guy
et al. 1980; Kamimura, 1994; Kues, 1994). Kues did show lesions
in the cornea of the eye and in vascular permeability (Kues, 1985,
1992, 1992a). This was seen using pulsed 2.45 GHz fields at a SAR
in the eye of 1.3-3.9 W/kg. Three exposures of 4 hours were given.
These changes were modified by pretreatment with ophthalmic drugs,
such as timolol maleate and pilocarpine. The threshold for the observed
effects was reduced to 0.26 W/kg. Kamimura (1994) did not observe
these changes, though they used continuous-wave exposure, rather
than pulsed. Kues (1999) found no ocular effects in rabbits or monkeys
after either single or repeated exposure to 10 mW/cm2 from a 60GHz
CW source, and Lu (2000) did not detect any eye damage in Rhesus
monkeys following exposure to 1.25 GHz microwaves. The latter authors
suggested that the retinal changes seen in Kues' 1992 study could
have been due to the fluorophotometric technique they used, and
repeated use of ketamine as an anaesthetic. Kojima (2004) showed
that lens changes after RFR at a high SAR were much more pronounced
in anesthetized rabbits than in non-anesthetized animals. They also
showed that the intraocular temperature was much higher in the anesthetized
rabbits. The same group (Hirata 2006) confirmed this result, and
also showed that a computational rabbit phantom gave results that
were in good agreement with results seen in experiments with live
animals. Ye (2002) found changes in the lens of rabbits exposed
to 5 or 10 mW/cm² microwave radiation at 2450 MHz frequency
for 3 hours. Dovrat (2005) exposed bovine lenses to 1.1 GHz at 2mW
and found that after 36 hours of exposure the optical function of
the lens was affected. At the microscopic level changes were seen
that were different from the cataracts seen with temperature increase. Elder (2003) published an extensive review of this subject. Further research appears warranted, in view of the different results seen in the reported studies. References: Authors
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