Cornea damage

Symptoms of exposure May irritate eyes and throat. Contact with eyes may cause cornea damage (Patnaik, 1992). An irritation concentration of 100.00 mg/m in air was reported by Ruth (1986). 

A Roles in vision, growth, reproduction Night blindness, cornea damage, damage to respiratory and... 

Other human-health effects of ultraviolet exposure include increased risks of developing cataracts and other damage to the cornea, damage to the retina, a suppressed immune system, sunburns of exposed skin, skin allergies, and an accelerated aging of the skin. 

Eyes, conjunctivae - edema Eyes, conjunctivae - injected Eyes, cornea - damage Eyes, lids - (edema) swelling... 

HUMAN HEALTH RISKS Acute risks irritation of eyes, skin and mucous membranes congestion in pharynx and trachea skin burns stenosis of upper respiratory system cornea damage polyps Chronic Risks chronic bronchitis bronchial constriction wheezing chemical pneumonitis pulmonary edema. 

CHRONIC HEALTH RISKS serious injury to liver and kidneys pulmonary edema jaundice prostration suppression of urine albuminuria hematuria cornea damage EPA Group B2 probable human carcinogen. 

Texicelegy Severe eye Irritant, may cause cornea damage severe skin Irritant Ing. can damage mucous membranes Inh. of vapors, esp. on heating. Is Irritating ethylene oxide (cancer and reprodudive hazard) may accumulate In storage and transport vessels... 

Hydraziae is toxic and readily absorbed by oral, dermal, or inhalation routes of exposure. Contact with hydraziae irritates the skin, eyes, and respiratory tract. Liquid splashed iato the eyes may cause permanent damage to the cornea. At high doses it can cause convulsions, but even low doses may result ia ceatral aervous system depressioa. Death from acute exposure results from coavulsioas, respiratory arrest, and cardiovascular coUapse. Repeated exposure may affect the lungs, Hver, and kidneys. Of the hydraziae derivatives studied, 1,1-dimethylhydrazine (UDMH) appears to be the least hepatotoxic monomethyl-hydrazine (MMH) seems to be more toxic to the kidneys. Evidence is limited as to the effect of hydraziae oa reproductioa and/or development however, animal studies demonstrate that only doses that produce toxicity ia pregaant rats result ia embryotoxicity (164). 

Vision is vital for human activities, and eyes are very sensitive to a number of toxic insults induced by chemical compounds. The most serious outcome is permanent eye damage which may be so severe as to cause loss of vision. The eye consists of the cornea and conjunctiva, the choroid, the iris, and the ciliary body. It also contains the retina, which is of neural origin, and the optic nerve. The retina contains photoreceptors, a highly specific light-sensitive type of neural tissue. The eye also contains the lens and a small cerebrospinal fluid system, the aqueous humor system, that is important for the maintenance of the steady state of hydration of the lens and thus the transparency of the eye. 

Toxicity. MEDINA is apparently non-toxic to rabbit penile mucosa its cumulative effect on abraded and intact rabbit skin is slightly greater than Tetryl no damage was observed to rabbit cornea and there was no evidence of sensitization by subcutaneous injection in guinea pigs. It was concluded that its toxicity is similar to that of Tetryl (Ref 11, p 138)... 

Injury (either physical or chemical) to the comeal endothelial cells has a marked efiect on occular function as these cells are responsible for maintaining the thickness and clarity of the cornea, yet they cannot be replaced if damaged. Immunohistochemical studies have revealed that enzymatic antioxidant defences, SOD, CAT and GSHPx, are similarly distributed in the corneal epithelium and endothelium (Rao etal., 1985 Attala et d., 1987, 1988). Other antioxidants include ascorbate, carotenoids and vitamin E (Fleath, 1962). 

In recent years considerable attention has focused on the mechanisms of oxidative damage to the cornea. In a study to determine the interaction of ascorbate, hydrogen peroxide and oxygen in the eye, Riley et al. (1986) found that ascorbate promoted corneal swelling when isolated corneas were perfused with glucose-deficient medium. This was due to the rapid oxidation of... 

GSHPx, CAT and SOD, which normally protect cells from free-radical damage have not been detected in aqueous humour. It has therefore been su ested that damage by free radicals and hydrogen peroxide to the anterior segment is prevented by a non-enzymatic extracellular oxidoreduction system involving a constant supply of reduced glutathione to the aqueous fluid from the ciliary epithelium, cornea and lens (Riley, 1983). 

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