Exploring the Differences in Today's Lens Care Options

BY KAARYN PEDERSON, OD
May 1999

Contact lens wearers are looking for lens care products that are effective, convenient and affordable. This article shows how some options measure up.

With current advances in contact lens technology, the number and types of contact lens solutions and products have increased dramatically. If you total the numbers of daily cleaners, multipurpose solutions, saline solutions, rewetting drops, storage solutions, daily protein removers, lubricating solutions, and enzymatic cleaners, you'll find over 100 options to choose from, not including generic or private-label products. It's easy to understand how we and our patients can become overwhelmed and even confused.

When discussing options, keep in mind that patients are not just contact lens wearers. With today's advertising, they are well-informed consumers. Accordingly, these patients want to know all of the available options and they seek products that are affordable and convenient.

The trend in contact lens care has been toward more effective yet convenient lens care systems to increase patient compliance and contact lens cleanliness and comfort. Consumers prefer "all-in-one" care regimens for soft and rigid gas permeable (RGP) lenses compared with traditional systems because they require less time and effort. Liquid enzyme cleaners are replacing traditional tablet enzymes because they are easy to use and eliminate the need for separate vials and steps.

Although these new options are convenient, you may wonder: How well do they work?

To help you better discuss these products with your patients, this article reviews a few of the new care products for RGP and soft lenses.

RGP Care Products

• Boston One-Step Liquid Enzymatic Cleaner vs. Alcon SupraClens: Similarities -- Both products have been designed to make enzyming fluorosilicone acrylate and silicone acrylate lenses simpler, faster and easier for the patients. Both enzymes are supplied in a liquid form, designed to be used with the manufacturers' accompanying storage solution. Because RGP wearers don't need a separate vial and saline solution, compliance is increased. And since the enzyme is already a liquid, no dissolving time is needed. Both enzymatic products help decrease lens deposits in two ways: They lyse bonds within protein molecules, breaking them into smaller pieces, and they reduce adherence of protein molecules to the contact lens surface, keeping lenses cleaner. Both products are preservative free.
  Differences -- The enzymes are not the same. Boston One-Step uses subtilisin, whereas SupraClens uses pancreatin. In addition, the usage indications for the two products are different. One drop of SupraClens is placed in a full lens case of Opti-Soak Daily Cleaner each day. The contact lenses must remain in this solution combination for at least 4 hours for proper cleaning and disinfection. Two drops of Boston One-Step must be placed in a full lens case of Boston Conditioning Solution every week. Both products require a thorough rinse before insertion. SupraClens should not be used by patients who are allergic to pork.
  Effectiveness -- Both companies claim increased cleaning efficacy and patient compliance with these new products compared with traditional enzyme cleaners. Boston One-Step Liquid Enzymatic Cleaner (when used specifically with the Boston Original, Advance Comfort or Simplicity formulations) is the one liquid enzyme approved solely for RGP contact lens use. However, SupraClens first was approved for use with soft lenses (only in conjunction with Opti-Free, Opti-Free Express and Opti-One) and later received approval for use with RGP materials (when used only with Opti-Soak). There is no difference in the SupraClens formulation used with soft or RGP materials.
  Cost Study -- To determine the cost difference between these two new products and a few other products that will be discussed later, I surveyed four large retail stores that sell contact lens care systems (Walgreens, Target, Rite-Aid and K-Mart). Prices were compared between stores and an average cost per product for this area was calculated (Fig. 1). (The prices listed are local area values, which may not reflect national price averages.)
  Results -- Although SupraClens is available in a 3-mL bottle labeled as a "30-day supply," when the container was emptied drop by drop, the 3-mL bottle actually was found to contain approximately 90 drops or 45 days of use per vial (one drop daily per eye). The average cost is $5.65 per bottle, which means patients pay $11.30 for two vials every 3 months if all 90 drops are used from each bottle. If the bottle is used for only 30 days, as listed on the packaging, it costs patients $16.95 every 3 months.
  The 2.4-mL bottle of Boston One-Step advertises a "12-week supply" on the label. Once again, by emptying the bottle drop by drop, each bottle actually contained approximately 60 drops or 15 weeks of use per vial (two drops weekly per eye). This liquid enzyme averages $8.74 per vial and lasts 3 months and 3 weeks if every drop is used. This makes the effective cost $6.99 for the 3-month period. However, the product label states that Boston One-Step Liquid Enzymatic Cleaner should be discarded 90 days after it is opened. If there are roughly 12 drops left in the bottle for three more weeks of use, should our patients throw it away or get their money's worth? To help answer this question, Gary Orsborn, director of Professional Marketing at Bausch & Lomb, explained that Boston One-Step recently was approved for a discard date 180 days after it is opened, despite the labeling. This means the enzymatic cleaner will remain effective if patients use it after the 3-month time period.
  Therefore, for a 3-month supply, Boston One-Step is $2.56 to $9.96 cheaper than SupraClens, depending on the actual number of drops used per bottle (listed amount vs. actual found). (These figures do not include the cost of the separate daily cleaners and conditioning solutions needed for complete lens care.) Patient compliance may be higher with the daily-use schedule of SupraClens, however.
• Allergan/Menicon Claris vs. Optimum by Lobob: Claris and Optimum care products are very effective, yet they are different cleaning systems for RGP contact lenses compared with most other brands. Both systems are replicas of the former DE-STAT products by Sherman Pharmaceuticals. Allergan purchased the rights to the previous DE-STAT 4 formulation, and Lobob obtained rights to Sherman DE-STAT 3. Therefore, Claris and Optimum cleaning and soaking contact lens solutions are essentially the same, with a few minor differences. Whichever product you use, one thing remains true -- the lens care system is a good option for RGP contact lens wearers.
  Similarities -- Although with most contact lens care systems the lenses are cleaned, rinsed and stored in a conditioning or insertion solution, with Claris and Optimum by Lobob, the contact lenses are stored in the cleaning solution and need to be rinsed before insertion. Because the contact lenses must soak in the cleaning solution at least 6 hours, these solutions effectively remove stubborn lipid deposits.
  Both cleaners contain the same two nonabrasive surfactants and require a mechanical rubbing step. Loose debris is rinsed away with sterile saline, and the lens is placed in the case containing the cleaning solution to be stored overnight. To avoid considerable irritation, patients must rinse their contact lenses with saline in the morning before applying the rewetting drops and inserting the lenses. Because the surfactant cleaners are nonabrasive, these solutions are recommended for high Dk RGP materials, including Menicon lenses. Other abrasive cleaners can scratch the lens surface, allowing deposits to adhere to the lens much easier and faster. Both solutions contain benzyl alcohol and sodium edetate as preservatives. Claris uses 0.3 percent benzyl alcohol compared with 0.1 percent in Optimum by Lobob.
  Claris is not available in retail stores. It is sold only to eye care professionals or directly to patients through the Claris Direct Patient Order Program. Optometric practitioners can find Optimum by Lobob through contact lens laboratories and distributors, while patients can purchase the solution through a direct order program or at selected Target stores. This allows eye care professionals greater control over the solutions patients use and eliminates retail competition.
  Differences -- Claris rewetting solution is the same as the Allergan Wet-N-Soak Rewetting Drops. It contains hydroxyethyl cellulose for lubrication and polixetonium chloride as the preservative. On the other hand, Optimum rewetting solution is the same as the Stay Wet 3 solution. It contains hydroxyethyl cellulose in addition to potassium and sodium salts, polyvinyl alcohol, sodium bisulfite and pyrrolidone for lubrication and comfort. This wetting solution is preserved with benzyl alcohol, sorbic acid and disodium edetate.
  Optimum also is sold with an additional extra-strength cleaner to be used on a weekly basis. This removes additional protein and lipids.
  Soft (Hydrophilic) Contact Lens Products

Soft (Hydrophilic) Contact Lens Products

• Bausch & Lomb ReNu MultiPlus vs. Allergan Complete Comfort Plus vs. CIBA Vision SOLOcare: Bausch & Lomb recently introduced ReNu MultiPlus, containing a unique "protein cleaning agent." This new formulation was the only single-bottle solution on the market claiming to remove protein and clean and disinfect without requiring a separate enzyme cleaner. However, both Allergan and CIBA Vision now advertise their solutions' effectiveness in removing protein without requiring a separate liquid or tablet enzymatic cleaners. It is important to realize that neither Allergan nor CIBA Vision has added additional proteolytic chemicals to these solutions.
  The Similarities -- Each is a multipurpose contact lens solution, requiring no separate cleaners or disinfectants. Most cleaning is achieved by a surfactant cleaner and a mechanical rub to each side of the contact lens for a total of 10 to 20 seconds. All three solutions use a similar surfactant cleaner. The surfactant binds to lipids and debris on the contact lens surface and then attaches itself to water. This loosens the particles to be rinsed away. The preservative acts as a chemical disinfectant, inhibiting bacterial contamination while the contact lenses soak. All three solutions use the same preservative, polyhexamethylene biguanide (PHMB), labeled under a different trade name. ReNu uses Dymed, Complete uses TriChem and SOLOcare uses polyhexanide at twice the concentration of the other two brands. For proper disinfection, the lenses must be stored in solution at least four hours. Each solution removes protein from the lenses chemically. They contain no enzymes.
  The Differences -- The active ingredients that remove protein are not the same. ReNu MultiPlus uses hydranate, a molecule with four negative charges, specifically added to help remove denatured protein. This molecule binds to calcium, which normally links protein molecules together, therefore breaking apart large protein chains, and binds to protein molecules, causing the highly negative charged protein/hydranate complex to be repelled from the surface of the contact lens.
  Complete Comfort Plus uses a surfactant cleaner, poloxamer 237 or Tyloxapol, to remove protein and debris when the contact lenses are rubbed. Additional protein is removed by incorporated electrolytes (such as potassium and sodium chlorides) whose high ionic strength attracts the opposingly charged protein molecules away from the contact lens surface as it soaks. (Complete Brand Comfort Plus also contains a lubricant, hydroxypropyl methylcellulose [HPMC], which helps retain eye moisture for added contact lens comfort.) Lastly, SOLOcare also uses a surfactant, poloxamer, or polyoxyethylene polypropylene block copolymer as a cleaning agent to remove protein and debris from contact lenses.
  Effectiveness -- Based on results from the manufacturers' internal clinical studies, Allergan states that Complete Brand Comfort Plus "removes nearly three times more protein than ReNu MultiPlus" and CIBA Vision advertises that SOLOcare is "proven to remove 41 percent more protein than ReNu MultiPlus." (Data are taken from internal studies available through Allergan and CIBA Vision.)
  The SOLOcare study was performed in vitro and concentrated only on native lysozyme protein, a clear protein naturally inherent in tears. Lysozyme protein is easy to remove from lenses passively with a simple saline soak. Denatured proteins (typically seen on soiled lenses) are more opaque, and they reduce comfort and visual acuity. The study did not use denatured proteins for comparison.
  Bausch & Lomb published their own studies, which show that ReNu MultiPlus clears protein 7 to 13 percent more effectively and eliminates lipids 29 to 37 percent better than Allergan Complete when used in conjunction with a weekly enzyme. Patients were also shown to prefer ReNu MultiPlus compared with Allergan complete solution. (Data are taken from internal studies available through Bausch & Lomb.) These studies used native and denatured proteins with lipid contamination for comparison.
  Both Complete Comfort Plus and SOLOcare still sell accompanying dissolvable tablet enzymes that may be used with their contact lens solutions, despite the companies' marketing claims that no additional enzymes are needed. The patient and practitioner can decide whether these additional enzymes are needed for weekly use.
  Cost Comparison -- In my survey of retailers, CIBA Vision's SOLOcare was considerably cheaper than the other brands, averaging $4.99 for a 12-fl-oz bottle (Fig. 2). Next in line was Allergan's Complete Comfort Plus, averaging $6.99 for a 12-fl-oz bottle, followed by Bausch & Lomb's ReNu MultiPlus, averaging $7.89 for the same size bottle.

Dr. Pederson is currently completing the cornea/contact lens residency at the University of California, Berkeley. She intends to join a practice in Sacremento, Calif.