Proclear from CooperVision uses a unique material, phosphorylcholine, that imitates substances found in human cell membranes.

How up to date are you on materials, designs, and care products? Take this quiz to find out how much you know.

Can you keep up with the changes in contact lens designs, materials, and care, and use your knowledge to choose the best lenses for your patients? Do you recall the properties of different lens materials and solutions that help increase patient satisfaction and reduce lens dropouts? Let’s find out.

1. Which of the following daily disposable lenses has the highest water content?
a. 1-Day Acuvue Moist (Johnson & Johnson Vision Care)
b. DAILIES AquaComfort Plus (Alcon Laboratories, Inc.)
c. Biotrue ONEday (Bausch + Lomb)

Correct answer is c.
At 78% water content, the surface of the Biotrue ONEday lens mimics the eye’s own healthy tears to retain moisture and shape. It matches the moisture level of the eye to support incredible comfort. Biotrue ONEday lenses employ a polymer that migrates from the lens matrix to the surface to prevent dehydration similar to the way the lipid layer prevents dehydration of the tear film.

2. In the Andrasko study of biocompatibility of various contact lens and multipurpose solutions, which multi-purpose solution had the lowest percentage of average corneal staining?
a. Opti-Free Replenish (Alcon)
b. Renu Freshâ„¢ (B+L)
c. BioTrue (B+L)
d. Opti-Free PureMoist (Alcon)

Correct answer is d.
Alcon’s Opti-Free PureMoist MPDS causes least amount of solution-induced corneal staining (SICS). SICS is caused by certain components found in contact lens solutions, which are taken up into the contact lens case and then released onto the cornea. Studies have shown SICS is the measurement of dying ocular surface cells. Studies have shown high levels of SICS to be linked to discomfort in the first two hours of lens wear.

Alcon’s Opti-Free PureMoist, which was designed to decrease corneal staining and promote contact lens end-of-day comfort, has disinfecting properties similar to other Opti-Free brand solutions. It contains both polyquaternium-1 (PQ-1) with myristamidopropyl dimethylamine (Aldox). Opti-Free PureMoist has a higher concentration of Aldox (0.0006%) compared to Alcon’s Opti-Free Replenish (0.0005%). With a Polyquad and Aldox dual-action disinfecting system, combined with the proprietary HydraGlyde Moisture Matrix wetting system, contributes to a decrease in corneal staining and enhanced patient comfort.

3. Which multipurpose disinfecting solution (MPDS) has a pH level equal to that of healthy tears?  
a. Biotrue
b. Opti-Free’ PureMoist (Alcon)
c. RevitaLens OcuTec (Abbott Medical Optics)
d. Renu Fresh

Correct answer is a.
Biotrue is Bausch + Lomb’s newest entry in the multipurpose contact lens solution market. Designed to mimic the biology of the eye itself, this solution contains a pH level equal to that of healthy tears, which the manufacturer says minimizes irritation upon contact lens insertion. Biotrue contains hyaluronan, a naturally occurring lubricant found in tears, which increases contact lens wettability. It also includes dual disinfectants””polyquaternium-1 and polyhexamethylene biguanide””to enhance the solution’s antimicrobial activity.

4. From an ocular health standpoint, the most significant property of silicone hydrogel lens material compared to hydrogel lenses is:
a. High Dk
b. Low Dk
c. High water content
d. High modulus

Correct answer: a
Silicone hydrogel materials differ from traditional hydrogel lenses because they have much greater Dk values. Greater Dk decreases or eliminates the complications induced by hypoxia. Silicone is even more permeable to oxygen than water. The lower the water content of a silicone hydrogel lens, the higher its permeability. The ability to combine silicone with a hydrogel component enables fluid permeability and on-eye movement.

5. What is the only lens brand cleared by the FDA to claim “may provide improved comfort for contact lens wearers who experience mild discomfort or symptoms relating to dryness during lens wear”?
a. Acuvue Oasys
b. Proclear  (CooperVision)
c. PureVision (B+L)
d. Air Optix (Alcon)

Correct answer: b
The CooperVision Proclear family of contacts features PC Technologyâ„¢, which uses a unique material, phosphorylcholine, that imitates substances found naturally in human cell membranes. These molecules naturally attract and surround themselves with water, keeping lenses feeling hydrated all day.

6. Why do SiHy lenses feel more comfortable for patients who have dry eye issues with contact lenses?
a. Less susceptibility to deposits
b. High oxygen transmissibility
c. Low water content
d. All of the above

Correct answer is d.
The reduced sensation of dryness of silicone hydrogel lenses is due to a number of characteristics. In addition to high oxygen transmissibility, SiHy lenses have improved wetting qualities, low water content, and less dehydration. The high oxygen transmissibility of SiHy lenses reduces physiological changes to the cornea and conjunctiva. Due to the low water content, SiHy materials are more resistant to the effects of dehydration.

7. According to an Alcon study on contact lens wear and care, what percentage of patients wear their lenses during sleep?
a. 1 in 10
b. 1 in 7
c. 1 in 5
d. 1 in 3

Correct answer is c.
According to Alcon, nearly one in five soft contact lens wearers wear their lenses while they’re sleeping, and among patients who sleep in their lenses, nearly two out of three are wearing lenses that are not approved for overnight wear.

8. PeroxiClear, by B+L, is the newest hydrogen peroxide solution on the market. The company states that its solution keeps lenses moist for long periods of time. This is possible due to:
a. Poloxamer 181
b. Propylene glycol
c. Carbamine
d. All of the above

Correct answer is d.
PeroxiClear utilizes Triple-Moist Technology””a combination of three different moisturizing agents: 1) poloxamer 181, a unique surfactant that attracts and retains moisture on lenses; 2) propylene glycol, a water-binding moisturizer; and 3) carbamide, a moisturizing agent that helps prevent dehydration. Together, these three agents help attract, spread, and retain moisture on the surface of the lens.

9. A distinguishing characteristic of Alcon’s DAILIES TOTAL1 compared to other daily disposable lenses is:
a. High water content core
b. Lubricity
c. Low Dk
d. Low water content surface

Correct answer is b.
DAILIES TOTAL1 is the first water gradient contact lens. It features a variation in water content from the lens core to the surface. Silicone hydrogel material with low water content offers high oxygen transmissibility at the core. At the surface, the lens has more than 80% water content and hydrophilic polymer chains that reduce friction with the eyelids. The lens has excellent lubricity, which is the inverse of friction. High lubricity correlates strongly with lens comfort.

Educating your patients about proper replacement and care of their contact lenses will help, but many will have noncompliant habits. Because comfort issues are the main reasons patients stop wearing contact lenses, prescribing the right combination of lens material and solution will go a long way toward success. That begins with testing your own knowledge of the properties of lens materials and solutions that can help increase patient satisfaction.

Eric L. Bran, Professional Editor of Optometric Office, is in a private group practice in Ridgefield, CT.


Abbott Medical Optics •800-347-5005 •amo-inc.com/products/corneal

Alcon Laboratories, Inc. •800-451-9337 •alcon.com

Bausch + Lomb •800-828-9030 •Bausch.com

CooperVision, Inc. •800-341-2020 •coopervision.com

Johnson & Johnson Vision Care, Inc. •800-843-2020 •ACUVUEProfessional.com


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