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.

Flyckt (2007) used a detailed anatomical equivalent of the human eye and orbit inserted in a whole-head model to assess SARs and temperature increases within the eye when a cell phone is in use. Their results suggested that the maximum temperature rises within the eye are too small to give harmful effects.

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
Dovrat A, Berenson R, Bormusov E, Lahav A, et al. (2005)
Title
Localised effects of microwave radiation on the intact eye lens in culture conditions.
Journal
Bioelectromagnetics 26:398-405.
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Authors
Flyckt VMM, Raaymakers BW, Kroeze H, Lagendijk JJW (2007):
Title
Calculation of SAR and temperature rise in a high-resolution vascularized model of the human eye and orbit when exposed to a dipole antenna at 900, 1500 and 1800 MHz. 
BJournal
Phys. Med. Biol. 52: 2691-2701.
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Authors

Hirata A, Watanabe S, Kojima M, Hata I, et al. (2006)
Title
Computational verification of anesthesia effect on temperature variations in rabbit eyes exposed to 2.45 GHz microwave energy.
Journal
Bioelectromagnetics 27:602-612.
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Authors
Kamimura Y, Saito K-I, Saiga T, Amenyima Y. (1994)
Title
Effect of 2.45 GHz microwave irradiation on monkey eyes.
Journal
IEICE Trans Commun. E77-B: 762-765.
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Authors

Kojima M, Hata I, Wake K, Watanabe S-i, et al. (2004)
Title
Influence of anesthesia and temperature in rabbit eyes exposed to microwaves.
Journal
Bioelectromagnetics 25:228-233.
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Authors

Kues HA, Hirst LW, Lutty GA, D'Anna SA, et al. (1995)
Title
Effects of 2.45 GHz microwaves on primate corneal endothelium.
Journal
Bioelectromagnetics 6:177-188.
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Authors

Kues HA, Monahan JC (1992)
Title
Microwave-induced changes to the primate eye.
Journal
Johns Hopkins APL Technical Digest 13:244-255.
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Authors

Kues HA, Monahan JC, D'Anna SA, McLeod DS, et al. (1992)
Title
Increased sensitivity of the non-human primate eye to microwave radiation following ophthalmic drug pretreatment.
Journal
Bioelectromagnetics 13:379-393.
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Authors

Kues HA, D'Anna SA, Oslander R, Green WR, et al. (1999)
Title
Absence of ocular effects after either single or repeated exposure to 10 mW/cm² from a 60GHz CW source.
Journal
Bioelectromagnetics 20:463-473.
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Authors

Lu S-T, Mathur SP, Stuck B, Zwick H, et al. (2000)
Title
Effects of high peak power microwaves on the retina of the Rhesus monkey.
Journal
Bioelectromagnetics 21:439-454.
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Authors
Yang L, Ge M, Guo J, Wang Q, Jiang X, Yan W. (2007).
Title
A simulation for effects of RF electromagnetic radiation from a mobile handset on eyes model using the finite-difference time-domain method.
Journal
Conf Proc IEEE Eng Med Biol Soc. 2007: 5294-7.

Authors
Ye J, Yao K, Zeng Q, Lu D (2002)
Title
Changes in gap junctional intercellular communication in rabbits' lens epithelial cells induced by low power density microwave radiation.
Journal
Chin Med J 115:1873-1876.
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Authors
Zareen N, Khan MY, Minhas LA. (2009)
Title
Derangement of chick embryo retinal differentiation caused by radiofrequency electromagnetic fields.
Journal
Congenit Anom (Kyoto). 49(1):15-9.

 

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