Eye Conditions & mercury exposure: references with snips from abstracts

Toimela and Tähti studied the effect of HgCl2 on cultured retinal pigment epithelial cells from pig and from a human cell line. They observed that 0.1 mM mercury reduced glutamate uptake by some 25 per cent. They interpreted this effect as due to inhibition of protein kinase C (PKC).

Toimela TA, Tahti H (2001) Effects of mercuric chloride exposure on the glutamate uptake by cultured retinal pigment epithelial cells. Toxicology In Vitro : an International Journal Published in Association with BIBRA 15: 7-12

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The retina of the eye accumulates mercury when there is exposure to mercury vapour. Mercury remains in the retina for a very long time -- often for years. Accumulation of mercury is seen, in monkeys, in the inner portion of the retina, in pigment epithelial cells and capillary walls (Warfvinge and Bruun 2000).

Warfvinge K (2000) Mercury distribution in the neonatal and adult cerebellum after vapor exposure of pregnant squirrel monkeys. Environ Res 83: 93-101

& Warfvinge K, Bruun A (2000) Mercury distribution in the squirrel monkey retina after in Utero exposure to vapor. Environ Res 83: 102-109

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Squirrel monkeys were exposed to mercury vapour at different concentrations and for different numbers of days. The calculated total mercury absorption ranged between 1.4-2.9 mg (range of daily absorption 0.02-0.04 mg). The monkeys were killed at different intervals after the end of exposure (range 1 month - 3 years) and the eyes were enucleated. Mapping of the mercury distribution in the eye revealed that the non-myelin-containing portion of the optic disc was densely loaded with mercury deposits, which are mostly confined to the capillary walls and the glial columns. The pigmented epithelium of the pars plicata of the ciliary body and of the retina contained a considerable amount of mercury. In addition, the retinal capillary walls were densely loaded with mercury deposits, even 3 years after exposure. It was also found that the inner layers of the retina accumulated mercury during a 3-year period. It is known that the biological half-time of mercury in the brain may exceed years. This seems also to be the case for the ocular tissue.

Warfvinge K, Bruun A. Mercury accumulation in the squirrel monkey eye after mercury vapour exposure. Toxicology. 1996 Mar 18;107(3):189-200.

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These data indicate that metallic Hg can induce a reversible impairment in color perception. This suggests that color vision testing should be included in studies on the early effects of Hg.

Cavalleri A, Gobba F. Reversible color vision loss in occupational exposure to metallic mercury. Environ Res 1998 May;77(2):173-7

& Cavalleri A, Belotti L, Gobba FM, Luzzana G, Rosa P & Seghizzi P. Colour vision loss in workers exposed to elemental mercury vapour. Toxicology Letters 77(1-3):351-356 (1995)

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Rudolph CJ, Samuels RT, McDanagh EW. Cheraskin E. Visual Field Evidence of Macular Degeneration Reversal Using a Combination of EDTA Chelation and Multiple Vitamin and Trace Mineral Therapy.In: Cranton EM, ed. A Textbook on EDTA Chelation Therapy, Second Edition. Charlottesville, Virginia: Hampton Roads Publishing Company; 2001

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Mercury can induce retinitis pigmentosa and cataracts

Uchino M, Tanaka Y, Ando Y, Yonehara T, Hara A, Mishima I, Okajima T, Ando M: Neurologic features of chronic minamata disease (organic mercury poisoning) and incidence of complications with aging. J Environ Sci Health B 1995 Sep;30(5):699-715

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Subclinical colour vision loss, mainly in the blue-yellow range, was observed in the workers. This effect was related to exposure, as indicated by the correlation between HgU and CCI (r=0.488, P<0.001).

Cavalleri A, Belotti L, Gobba FM, Luzzana G, Rosa P & Seghizzi P. Colour vision loss in workers exposed to elemental mercury vapour. Toxicology Letters 77(1-3):351-356 (1995)

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The effect of inorganic mercury on the integrity of the endothelium of isolated bullfrog (Rana catesbeiana) corneas was examined by spectrophotometric analysis of corneal uptake of the vital stain Janus green, and by both transmission (TEM) and scanning (SEM) electron microscopy.

TEM and SEM demonstrate significant ultrastructural damage to the endothelium exposed to inorganic mercury, including cellular swelling, increased vacuolization, focal denuding of Descemet's membrane, and diminished integrity at the intercellular junctions.

Sillman AJ, Weidner WJ. Low levels of inorganic mercury damage the corneal endothelium.
Exp Eye Res. 1993 Nov;57(5):549-55.

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Ubels JL, Osgood TB. Inhibition of corneal epithelial cell migration by cadmium and mercury.

Bull Environ Contam Toxicol. 1991 Feb;46(2):230-6.