Contact lens cleaning

Sulfides, thiols, and proteinacious organic matter, particularly plasma and whole blood, seriously depress and may even aboHsh the germicidal action of mercury compounds (qv). As of this writing approved uses for mercurials are limited to contact lens cleaning fluids, spoilage prevention of stored... 

The management of GPC depends on the severity of symptoms. Management includes frequent lens replacement or disposable contact lenses, appropriate contact lens cleaning, and vigilant monitoring of contact lens wearing time. Medical management includes use of mast cell stabilizers, topical NSAIDs, and steroids. 

In addition, assessment of the patient s contact lens cleaning regimen is also important. Cleaning regimen, once a critical component to lens care, has been eliminated with daily disposable lens replacement and has evolved with frequent lens replacement. Daily cleaning is essential, and when applicable, disinfection with a hydrogen peroxide system may still be an important consideration.The use of enzymatic cleaning has diminished because disposable lenses have replaced the need for it, but it may be a consideration in select cases. 

Write a set of instructions that could be included in a package of contact-lens cleaning solution containing an enzyme. This enzyme catalyzes the breakdown of protein residues that adhere to the lenses. Include information about the structure and function of enzymes and the care that must be taken to avoid their denaturation during use. 

Other Uses Enzymes work outside your body, too. One class of enzymes, called proteases (PROH tee ay ses), specializes in protein reactions. They work within cells to break down large, complex molecules called proteins. The meat tenderizer shown in Figure 20 contains proteases that break down protein in meat, making it more tender. Contact lens cleaning solutions also contain proteases that break down proteins from your eyes that can collect on your lenses and cloud your view. 

Many different compormds are able to act as catalysts. The most powerful catalysts are those foimd in nature. They are needed to speed up the reactions necessary for a cell to function efficiently. These biological catalysts are called enzymes. Enzymes help your body use food for fuel, build up your bones and muscles, and store extra energy as fat. Enzymes are involved in almost every process in a cell. For example, proteases are enzymes that break down proteins, as shown in Figure 6.22. These enzymes occur naturally in cells to help with recycling proteins so their parts can be used over and over. Proteases are also used in many common products, including contact lens-cleaning solution and meat tenderizer. 

Proteases in contact lens-cleaning solutions help remove the grimy buildup on lenses that results from proteins secreted by cells around the eyes. 

Real-World Reading Link Some cleaning products, such as contact lens cleaning solution, contain enzymes. Did you ever wonder what an enzyme was ... 

Occupational allergic contact dermatitis to metallic mercury is rare and is mainly seen among dental personnel (Goh and Ng 1988 Ancona et al. 1982 Kanerva et al. 1993). The majority of positive patch-test reactions to mercury and to mercury compounds are related to non-occupational exposure, e.g., dental amalgam, mercury from broken thermometers, thio-mersal in vaccines, and contact lens cleaning solutions. 

The diminution of electrode fouling in oxido-reductive mode is shown in Fig. 22. Other ECL systems were also examined and sonoelectrochemical enhancement was observed for luminol (3-aminophthalhydrazide). This system has been thoroughly studied for the detection of low concentrations of residual hydrogen peroxide in contact-lens cleaning solutions. The ECL intensity of 9,10-diphenyl-anthracene in sonicated DMF solutions was increased by factors of 20-30 depending on the concentration of the solutions, ultrasound power, and fre-quencyT Similar effects were observed from l,5-diphenyl-3-styrylpyrazoline, rubrene, 9,10-dimethyl-anthracene, and perylene. ... 

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