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84 Cards in this Set
- Front
- Back
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What are the 3 products in a lens care system?
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Product to: clean, rinse, disinfect.
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The majority of microorganisms is removed during which step?
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Cleaning step
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Daily cleaning removes _____ proteins, but not ____ proteins.
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loose proteins, bound proteins.
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What are the 5 qualities of an ideal care system?
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Efficacy, non-toxic, compatibility, simplicity, affordability.
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What does tonicity describe in a contact lens solution?
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Salt concentration.
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What is the normal salt concentration in a contact lens solution?
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.9% (same as intracelluar fluid)
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If a soaking solution is hypertonic, what will this do to the contact lens?
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Contact lens becomes smaller and steeper.
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If a soaking solution is hypertonic what will this do to the cornea?
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Pulls water from the cornea.
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If a soaking solution is hypotonic, what will this do the the contact lens?
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Contact lens becomes thicker, larger and flatter?
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If a soaking solution is hypotonic, what will this do the the cornea?
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Causes corneal edema.
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What pH must the solution be for it to be comfortable for the eye?
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6.6-7.8
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What is added to contact lens solutions to adjust for proper pH?
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HCL and NaOH
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What are four common buffers?
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Borate, Phosphate, Citrate, Tromethamine.
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What is borate?
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buffer
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What is phosphate?
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buffer
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What is citrate?
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Buffer
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What is tromethamine?
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Buffer
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Why is it a bad idea to leave contact lens solution containers open?
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CO2 can go in, causing it to form carbonic acid, which lowers the pH of the solution.
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What does the viscosity of a solution refer to?
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thickness
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Cleansers tend to have ___ viscosity to enhance contact with the lens surface.
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high
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What are four common viscosity agents?
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Glycols, Polyvinyl alcohol, methylcellulose, Hydroxymethylcellulose.
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What are glycols?
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viscosity agent
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What is polyvinyl alcohol?
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viscosity agent
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What is methylcellulose?
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viscosity agent
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What is hydroxymethylcellulose?
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viscosity agent
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What resists or prevents growth of an organism in solution?
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Preservative
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What eliminates organisms from a contact lens?
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Disinfectant
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Can a preservative be a disinfectant?
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Yes, if it is strong enough to be cidal.
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Besides using chemicals, what is another form of disinfectant for hydrogels?
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Heat
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What class of hydrogels can you not heat up to disinfect?
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Group 4
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What can heat do to deposits on lenses?
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Cook the deposits on.
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What is one of the first soft contact lens preservative that is mercury based?
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Thimerosal
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Why is thimerosal no longer used?
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It causes hypersensitivity reactions. Can also cause SLK.
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Is thimerosal a small or large molecule? What implication does this have?
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Small molecule, so it can be absorbed into the contact lens and then released throughout the day as it is being worn.
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What is chlorhexidine?
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Preservative and disinfectant.
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What organisms does chlorhexidine kill? Not kill?
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Kills bacteria, not fungi.
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What is a side affect of chlorhexidine?
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Allergies and toxic reactions.
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What type of contact lenses is chlorhexidine often used in combo with?
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Used for RGP's, not used for soft CL at all.
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What is chlorhexadine often used in combo with?
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Thimerosal
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Is chlorhexidine a small or large molecule?
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Small
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What are three types of biguanides?
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Polyaminopropyl biguanide, PHMB (Polyhexamethylamine biguanide), Polyhexadine.
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Are biguanides small or large molecules? What is the implication of this?
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Big molecules so it is not absorbed into the CL or bound onto the CL.
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What organisms is hydrogen peroxide a good disinfectant for?
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Good for bacteria and fungi. Not good for acanthomoeba cysts.
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At what concentration is hydrogen peroxide a good disinfectant?
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3%
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Can hydrogen peroxide be a preservative?
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Yes, if it is at a low concentration.
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What is an important component when using a hydrogen peroxide as a disinfectant?
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It must be neutralized.
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Hydrogen peroxide penetrates the ____ ____, possibly improving efficacy.
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Lens matrix
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What type of people are hydrogen peroxide cleaners good for?
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People with allergies or long-term contact lens users.
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Why can't you use hydrogen peroxide in a brown bottle as a disinfectant?
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It is not purified (may contain heavy metals that can bind to the eye.)
The labeled concentration on the bottle is not exact so it may not provide the proper disinfection. |
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What company makes polyquad?
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Alcon
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What is polyquad?
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Preservative or disinfectant, depending on the concentration.
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Is polyquad a large or small molecule?
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Large
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What is another name for aldox?
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Myristamidopropyl dimethylamine
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What is another name for myristamidopropyl dimethylamine?
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Aldol
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What is the only solution on the market that has "stand-alone" approval as a disinfecting solution?
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Opti-free, because it contains Aldox.
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Aldox is good against what organisms?
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Bacteria and fungi.
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What ingredient in a disinfecting solution is good at killing both bacteria and fungi?
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Aldox
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What does BAK stand for?
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Benzoalkonium chloride
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BAK is found in what type of solutions?
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RGP solutions, artificial tears, pharmaceuticals.
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Why is BAK not used with soft CL?
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It easily binds and causes toxic reaction.
*Therefore, be careful not to use eye-washes with soft contact lenses. |
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What type of contact lens is BAK not used with?
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Soft contact lenses.
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What does EDTA stand for?
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Ethylenediamine-tetra-acetic acid
AKA: edatate disodium |
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How does BAK work?
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Like a detergent which disrupts cell membranes.
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What type of agent is EDTA?
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Chelating agent.
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How does EDTA work?
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It is a chelating agent that binds onto metal ions needed for bacterial growth.
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Why is EDTA used to enhance the activity of other preservatives?
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It kills gram negetive bacteria.
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What is sorbic acid?
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A preservative (static agent).
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Why does sorbic acid cause stinging?
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Because it is best at low pH. Low pH causes stinging.
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What are some side effects of using sorbic acid?
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Causes stinging due to low pH.
Can cause soft contact lenses to become yellow. |
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Since sorbic acid can cause soft contact lenses to become yellow, what type of solutions is it not used much with anymore? What solutions can it be found in?
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Not used in salines much. Can be in cleaners.
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Most contact lens cleaning agents are _______.
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Surfactants
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How does a surfactant work?
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It is similar to phospholipids. It removes debris by forming a micelle.
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Which of the following is not a surfactant?
a) Poloxamine b) Pluronic c) Sodium citrate d) Isopropyl alcohol |
c) Sodium citrate
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What are 3 surfactants?
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Pluronic, Poloxamine, Isopropyl alcohol.
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What type of surfactant is found in Miraflow?
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Isopropyl alcohol.
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What is sodium citrate?
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A cleaning and buffering agent.
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What does isopropyl alcohol kill?
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Active (trophozoite) and inactive (cyst) form of acanthamoeba.
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What type of surfactant can kill the inactive and active form of acanthomoeba?
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Isopropyl alcohol
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Traditionally, what form were protein removers in?
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A tablet form. Today drops are available.
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_____ is claimed to be able to remove proteins during soak.
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Sodium citrate
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What is hydranate?
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Protein remover.
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How does hydranate work?
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Chelates calcium, thought to be a link between proteins and lens surface.
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What product is hydranate found in?
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ReNu
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What type of care systems are available?
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Multi-purpose solutions, Two-bottle systems, Three-bottle systems.
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