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Preparations for contact care
Trading in your spectacles for a 360-degree view used to mean inheriting a complex bathroom routine, performed every morning and evening to the accompaniment of various bottled solutions, cleaners, and gadgets. Today, the wide choice of lenses and advanced maintenance routines makes life a little easier. Still, contacts do require some extra attention and care. What's more, contacts present an extra risk of eye injury or damage. Doing things right will extend the life of your lenses and ensure safe, comfortable day-in and day-out wear. And always heed the advice of your eye doctor. After all, these are the only eyes you've got.br>
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Contact Caveats
Proper contact care varies with different types of lenses, but a few red flags apply to all. Stick to products approved by the FDA for use with your lenses and don't mix solutions from different manufacturers. Since many products can become contaminated with nasty bacteria over time, never keep a solution beyond its recommended disposal date.
Solutions, Solutions
Whatever type of lens you use (hard, soft, or rigid gas-permeable, better known as RGP), your care regimen will involve some bottled solutions -- liquids used to clean, rinse, soak, or wet the contacts. Know the type of lens you use and follow your eye care professional's recommendations. The following is a rundown of the types of solutions that may be included in your lens care arsenal:
- Cleaning solutions: lenses of all types become caked with substances from both the eye and the atmosphere. You can't always see them (especially without your contacts), but they're there. Cleaning agents gently break down and loosen these undesirables.
- Enzymatic cleaners: soft lenses and silicone acrylate RGP lenses are prone to a buildup of proteins not unlike the soap scum that accumulates on shower walls, so they need a little extra housekeeping in the form of a once-a-week enzyme cleaning. Most products come in tablets that are dissolved in a solution recommended by the manufacturer. Soft lenses must be disinfected after an enzymatic cleaning and some products incorporate this function into a one-step process.
- Disinfectants: soft lenses need to be disinfected each time prior to reinsertion. There are two basic types of disinfectants. Those containing disinfecting preservatives require a soaking time of anywhere from five minutes to four hours. Those based on hydrogen peroxide require neutralization using either a neutralizing solution, a delayed-release neutralizing tablet placed in the disinfectant itself, a platinum disc system, or a heat-based unit.
- Saline solutions: with soft contacts, saline solutions are used for rinsing, storing, and even disinfecting in heat-based devices. They're available with or without preservatives that prolong their shelf life, but may irritate some wearers' eyes. Preservative-free solutions are available in single-use, throwaway containers as well as larger bottles that must be discarded within two weeks to a month. Always use saline solutions specifically made for use with contacts as others may cause trouble.
- Soaking solutions: hard and RGP lenses dry out as you wear them. Soaking solutions put eye-comforting moisture back in and help lift away any deposits that cleaning didn't remove. Some high-silicone RGP lenses need special soaking solutions called conditioning solutions. An important note: don't reuse soaking solution. Replace it after each use.
- Wetting solutions: for RGP and hard lenses, wetting solutions create a cushion between your eye and the lens and also help protect lenses as you insert them.
- Rewetting solutions: essentially eye drops for lens wearers, rewetting solutions clean and rewet lenses while they're in the eye -- especially helpful with extended-wear lenses. When inserting any type of lens, if a few blinks don't clear your vision, try using a drop or two of rewetting solution.
- Combination products: some solutions are multifunctional, combining cleaning, soaking, and wetting in a single product. While this is great for freeing up space in the medicine cabinet, the ingredients needed for wetting may gum up the works when it comes to cleaning.
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Hard lenses
Hard lenses are made from an organic polymer (plastic). They do not allow oxygen to pass through freely and are associated with many eye disorders.
Soft lenses
Soft lenses are also made from polymers, but they contain a high concentration of water. Some lenses are 70% water when fully hydrated. This gives them a soft and comfortable feel. But these lenses require more care.
Rigid gas-permeable lenses
Rigid gas-permeable lenses combine a few qualities of hard and soft lenses. They have the structure and firmness of hard lenses, but do not cut off the flow of oxygen to the eye. Unfortunately, they do not feel as comfortable as soft lenses, but they require less care when handling.
Demulcents
Demulcents serve to coat, moisten, and lubricate the eyes. Though demulcents comprise a small portion of artificial tears, they help hold moisture in the eye. They are relatively inert substances when used in the eye and should not cause eye irritation.
Enzymatic agents
Enzymatic agents are proteins that help perform many chemical reactions. They are usually found in contact lens tablets and in some solutions for soft and gas-permeable contact lenses. These enzymes help to break up protein and other buildup stuck on your contact lenses. They can help preserve, comfort, and lengthen the amount of time contact lenses can be used.
Neutralizers
Neutralizers are needed for some soft contact lens disinfectant products that contain hydrogen peroxide, which is a good disinfectant, but will irritate your eyes. Neutralizers break down hydrogen peroxide into water and oxygen so that no hydrogen peroxide will be left when the contact is put back in your eye.
Surfactants
Getting dirt and oil off your contacts would be hard without surfactants. They are equally at home in oily or watery substances, or both at once. You can think of surfactants as having two parts. One part likes to be nestled in oil and the other part prefers water. The net result: when you wash away the surfactant with water, the water-like half follows, dragging along the oil-like half, which drags away the dirt.
Preservatives
Preservatives keep those pesky microbes from roosting in your contact lenses. They do this in one of two ways: they either stop bacteria and fungi from growing or they kill microbes. Either way, the result is that you'll feel more comfortable wearing your contacts.
| Hard Lenses | Ingredient | Description |
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| Polymethylmethacrylate (PMMA) | ? | The first contact lens material, it's hard and oxygen-impermeable. Less than 1% of contact wearers use PMMA and for good reason. PMMA-based hard lenses seem to make wearers more prone to developing vision and eye problems. | | Soft Lenses | Ingredient | Description |
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| Hydroxyethylmethacrylate (HEMA) | ? | The first soft contact lens material, used for daily wear, disposable, planned replacement, and extended wear lenses. Contains 38% water. | | Hefilcon | ? | The second polymer used for soft lenses. It's a copolymer of HEMA and N-vinyl-2-pyrrolidone (NVP), and is 45% water. | | Hioxifilcon | ? | Another soft lens material, it's a copolymer of HEMA and glycerylmonomethacrylate (GMA). Hioxifilcon is 48% water. | | Methafilcon | ? | A soft lens material that's relatively strong. It's a copolymer of HEMA and methacrylic acid (MAA), and contains 55% water when hydrated. | | Lidofilcon | ? | A copolymer of methylmethacrylate (MMA) and N-vinyl-2-pyrrolidone (NVP), it was developed for use in extended wear lenses and contains 70% water when hydrated. | | Rigid Gas-Permeable Lenses | Ingredient | Description |
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| Cellulose acetate butyrate | ? | An inflexible material that forms RGP lenses. More gas-permeable than materials that compose hard lenses, but less gas-permeable than other materials used for RGP lenses. Tends to warp and scratch easily. | | Alkyl styrene copolymers | ? | An RGP lens material that's lighter and less gas-permeable than other RGP lenses. Unfortunately, it's also comparatively more brittle and dries easily. | | Demulcents | Ingredient | Description |
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| Cellulose derivatives | ? | Some include methylcellulose and hydroxypropylmethylcellulose. Cellulose-derived demulcents are effective but known to cause adverse reactions. | | Dextran 70 | ? | Produced by bacteria grown on sucrose (table sugar), it's safe and effective. | | Liquid polyols | ? | Some include polyethylene glycols, glycerin, and propylene glycol. These are safe and effective demulcents. | | Polyvinyl alcohol | ? | A safe product that is less viscous than other artificial tear substances. | | Enzymatic Agents | Ingredient | Description |
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| Papain | ? | An enzyme also found in meat tenderizers, papain helps remove protein deposits on contacts by dissolving materials away. Allergic reactions may occur. | | Pancreatin | ? | A purified pancreatic enzyme, pancreatin is used to digest proteins and thus is effective on protein deposits on contacts. Allergic reactions may occur. | | Subtilisin | ? | An enzyme that helps remove protein deposit buildups on contacts. | | Neutralizers | Ingredient | Description |
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| Platinum | ? | This metal forms the platinum disc that neutralizes the hydrogen peroxide in contact lens disinfecting products. | | Catalase | ? | An enzyme that helps convert hydrogen peroxide into harmless oxygen and water. | | Sodium pyruvate | ? | Helps to inactivate hydrogen peroxide. | | Sodium thiosulfate | ? | Helps to inactivate hydrogen peroxide. | | Surfactants | Ingredient | Description |
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| Sodium lauryl sulfate | ? | Also known as sodium dodecylsulfate (SDS), it's a strong detergent needed to loosen dirt from your contacts. | | Preservatives | Ingredient | Description |
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| Sorbic acid | ? | Used to inhibit the growth of fungi (mold and yeast), which is dependent on pH. | | Thimerosal (mercurochrome) | ? | Contains mercury and is effective at preventing both bacterial and fungal growth. Don't use it if you're allergic to mercury or salicylates. | | Benzalkonium chloride (BAK) | ? | Used as a surfactant in many cosmetic products, but it also has antimicrobial activity. | | Chlorhexidine | ? | A basic topical antiseptic. It also has the potential to be very irritating. | | Polyquarternium-1 | ? | One of the new preservatives, it's a quaternary ammonium compound that has antimicrobial activity. | | Phenylmercuric nitrate | ? | Contains mercury. | | Polyaminopropylbiguanide | ? | One of the newer and more popular ingredients in contact lens solutions, it has antimicrobial properties. | | Hydrogen peroxide | ? | A strong oxidizing agent that is effective against both bacteria and fungi, it is highly irritating to your eyes if not properly neutralized. |
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Appropriate Uses
Cleaning solution
Contains surfactant cleaners that remove oil, protein, and debris from the lens surface. Also prevents bacterial contamination and growth.
Conditioning solution
Disinfects and increases comfort of RGP lenses.
Enzymatic cleaning solution
Removes protein and other deposits on lenses that can't be removed by daily cleaning solutions.
Rewetting solution
Rehydrates the contact lens while it's in the eye, increasing comfort.
Saline solution
Rinses and disinfects soft contact lenses. Also used to store soft lenses in a sterile, buffered environment whenever they are not in the eye. Prevents calcium deposits from forming on the lenses if it contains EDTA.
Soaking solution
Stores lenses in a sterile environment whenever they are not being used and keeps lenses hydrated to maintain optimum comfort and vision when worn.
Wetting solution
Wets the surface of the lens so it can easily adhere to the eye. Also places a lubricating layer between the lens and eye so the contacts are more comfortable to wear.
Common Misconceptions
Saline solution
Using saline made at home by dissolving salt tablets in water is not recommended due to risk of serious infection.
Soaking solution
Using saline made at home by dissolving salt tablets in water is not recommended due to risk of serious infection.
Wetting solution
Using saline made at home by dissolving salt tablets in water is not recommended due to risk of serious infection.
Keeping Your Vision Clear
- You will receive instructions from your eye care practitioner on how to care for your lenses. Follow those instructions when in doubt.
- Refer to individual package instructions as well.
- Each of the daily steps should be performed each time lenses are removed from the eye to ensure optimal lens care. None of the steps alone is adequate.
- Use products specifically designed for your lens type. Do not substitute products from different manufacturers.
- Make sure your hands are clean and free of lotions and cosmetics before touching eyes or handling lenses.
- See your eye care practitioner regularly (at least once per year).
Basic Hard Lens Care
- There are three steps in hard lens care: cleaning, soaking, and wetting.
- You can clean hard lenses one of four different ways: friction rubbing, spray cleaning, hydraulic cleaning, or ultrasonic cleaning.
- To clean your lenses by friction rubbing, add cleaning solution to each side of the lens and gently rub the lens for about 20 seconds between your thumb and forefinger or between one forefinger and the palm of the opposite hand.
- Spray cleaning requires the use of a perforated holder. The lens is placed into the holder and held under running water. Do not rinse lenses with very hot or very cold water as lenses may warp.
- To clean lenses hydraulically, place lenses in the baskets, fill the container with cleaning solution, and rotate the cap for 20 to 30 seconds.
- Ultrasonic cleaning units use ultrasonic waves to loosen debris.
- Contact lenses must be soaked when stored. Use special soaking solutions rather than tap water.
- Dehydrated lenses will cause discomfort if placed in the eye, as well as make cleaning more difficult.
- Wet the lens with a wetting solution before inserting into the eye.
- Rewetting solution can be used to clean and rewet the lens while it's in the eye, but it's better to take the lens out to clean and rewet it.
Basic Rigid Gas-Permeable (RGP) Lens Care
- RGP lens care is very similar to that of hard lenses: cleaning, weekly enzymatic cleaning, soaking with conditioning solution, and wetting.
- To clean your lenses by friction rubbing, add cleaning solution to each side of the lens and very gently rub both sides of the lens for about 20 seconds between one forefinger and the palm of the opposite hand.
- Conditioning solutions are usually preferred to soaking solutions because of the low surface wetability of RGP lenses.
- You must soak lenses in solution for at least four hours before reinsertion into your eyes.
- Rewetting solution can be used to rewet the lens and eye if the lens begins to dry out.
- To remove protein buildup on the lens, use an enzymatic cleaner once a week.
Basic Soft Lens Care
- Soft lens care involves multiple steps: daily cleaning, weekly enzymatic cleaning, disinfection and neutralization, soaking, and wetting.
- Soft lenses must be cleaned daily with a surfactant cleaner or every time lenses are removed in the case of extended wear lenses.
- Place cleaner on lens and rub for 20 to 30 seconds between your thumb and forefinger or between one forefinger and the palm of the opposite hand.
- After cleaning, the lens should be rinsed thoroughly with a sterile saline rinsing/soaking solution to avoid eye irritation.
- Thermal or chemical disinfection of lenses is crucial to ensure that the lenses do not become contaminated.
- For thermal disinfection, place clean lenses into separate compartments of a storage case filled with saline. Place the case into the heating unit and increase temperature as directed. Replace cases or units if damaged.
- One method of chemical disinfection involves using a chlorhexidine solution. Store lenses in this solution for at least four hours. If the lens is stored in this way for more than three days, clean and disinfect with fresh solution for four hours.
- The second chemical disinfection method uses hydrogen peroxide solution followed by neutralization. Follow manufacturer's instructions for disinfection and neutralization steps, paying careful attention to the proper length of time.
- Store lenses in rinsing/soaking solution. If lenses are left in the case for more than 24 hours, disinfection must be repeated.
- Rewetting solutions can be used in 1- to 2-drop doses if dehydration of lenses occurs.
- For protein removal, use an enzymatic cleaner weekly or biweekly. Let the lenses soak from 15 minutes to overnight, depending on manufacturer's instructions.
Storing Contact Lens Solutions
- The one-unit containers of preservative-free buffered saline must be discarded after a single use.
- Multiuse bottles of preservative-free buffered saline should be discarded 14 to 30 days after opening.
- Nonpreserved, nonaerosol saline can be used for about 15 days.
- Saline that contains EDTA lasts about 30 days.
Lens Case Care
- Clean cases thoroughly every week.
- Replace cases every six months.
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More Than Taking Your Contacts Out Every Night
- Do not use if you are allergic to any ingredient in the product.
- Routine use of any contact lens solution raises the risk of bacterial contamination.
- Solutions from different manufacturers should not be mixed.
- If you are already using another eye care product, consult a doctor.
- Combination products for cleaning, soaking, and wetting are more likely to cause irritation and less likely to be effective in killing bacteria.
- For polyvinyl alcohol-based products, do not use any eye medications concurrently that contain sodium bicarbonate, sodium borate, or the sulfates of sodium, potassium, and zinc.
- Never use saliva to wet contact lenses. Your contact lenses may absorb chemicals left over from foods that can irritate your eye or bacteria from your mouth can be transferred to your eye causing infection.
- Packaged solutions are better. Homemade saline solutions with salt tablets can increase the risk of acanthamoeba keratitis, a serious vision-threatening eye disease. Commercial saline solutions are recommended.
- Consult a doctor before using these products if you have had an eye disease, damage, or infection in the past.
- Discontinue use and consult a doctor if you experience eye irritation, blurred vision, or dilation of pupils.
Be Careful with This Stuff
- Temporary discomfort and blurred vision may occur when solution mixes with tears.
- As solution dries, it may cause crusty residue to fall into the eye and cause irritation.
- Ocular decongestants should not be used when contacts are in the eye. They can induce conjunctival hypoxia with routine use.
- Chlorhexidine:
- Do not use solution if it appears greenish in color, indicating decomposition.
- Do not use with rigid gas-permeable lenses because disinfecting action is impaired.
- If the product looks cloudy, has changed colors, or you suspect that the product is contaminated, discard it.
Perservatives and Disinfectants Can Irritate
Benzalkonium chloride:- Can cause ocular irritation due to buildup.
- Do not use with soft contact lenses; they absorb the chemical and can result in severe toxicity.
- High concentration in solution used with hard lenses may cause ocular damage.
Thimerosal (sodium ethylmercurithiosalicylate):- Incompatible with benzalkonium chloride.
- May bind to debris in soft contact lenses and cause irritation.
- Individual may become sensitized after extended use.
Sorbic acid and potassium sorbate:- Less effective as an antimicrobial agent.
- May increase age-associated yellowing of some contact lenses.
Chlorhexidine:- May cause eye irritation.
- May cause surface clouding when used with silicone or styrene rigid gas-permeable lenses.
Hydrogen peroxide:- Cracking and brittleness of lenses occurs if used to disinfect fluorosilicone acrylate rigid gas-permeable lenses.
- If you skip the neutralization step of hydrogen peroxide disinfection before placing the lens into the eye, you could experience pain, photosensitivity, and possible corneal damage.
- Ingredients may cause contact dermatitis on skin.
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Websites, Organizations & Manufacturers
Sources & Further Reading
Books
- 1. Facts & Comparisons.Drug Facts & Comparasons. Facts & Comparisons.
- 2. Covington, TR; RR Berardi, LL Young, SC Kendall, MJ Hickey.Handbook of Nonprescription Drugs. American Pharmaceutical Association, Washington DC, 1996.
- 3. Food & Drug Administration.Federal Register 12/18/92; 3/4/88.
- 4. Knodel, LC.Nonprescription Products: Formulations & Features '98-99. Americam Pharmaceutical Association. Washington DC 1998.
Find more books on health and wellness at  barnesandnoble.com.
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