What GP lens material do you recommend?
(A list of materials is available on this website.)
“It’s important not to get too caught up with the large number of materials that are presently available. Utilize the laboratory consultant for this decision. They know how to match material with design and patient. I often recommend high Dk lens materials, erring on the side of oxygen to avoid corneal hypoxia. They also hold up better under stressful situations — such as ultrathin and toric designs — than previous-generation high Dk lens materials. You don’t see 3 and 9 o’clock staining as much with these materials, due to the quality of manufacturing with better-wetting high Dk materials and ultrathin designs resulting in less inferior decentration.” (Keith Parker, Advanced Vision Technologies)
“We use several different materials, and we will recommend a specific material for a given design and patient. As with the GP Lens Institute, we have all of the materials and their respective properties on our website.” (George Mera, Tru-Form Optics)
“There is a wide array of GP materials available today that will provide the best product for patients’ needs. High Dk materials provide the most oxygen to the cornea; low specific gravity materials are useful in combating thick lens designs; high specific gravity materials aid in reducing high-riding lenses due to excessive upper lid attachment; and more rigid materials reduce lens flexure. The material of choice will depend on the needs of the patients and the design of choice.” (Ann Shackelford, ABB Optical Group)
“Lens materials have come a long way. I am so happy to see higher Dk materials with a wettability that is better than lower Dk ones. ECPs always had to choose between a material that wets well and material that provides more oxygen permeability.” (Manoel Cavalho, BostonSight)
“Myriad GP materials are available that cover a wide range of Dk values. Our fitting consultants will assist in matching the best material to your specific patient needs. We are no longer concerned with the wettability of hyper Dk materials now that Tangible Hydra-PEG (THP) is available.” (Mike Johnson, Art Optical)
“The material providers have all done a good job in creating a wide range of materials. Choosing a lens material has a lot to do with the patient condition and history. As consultants, we look to provide the practitioner with support in choosing the highest possible Dk, wettability, and stability, but ultimately can provide any material that the doctor requests that will give the best clinical outcome.” (Derrell James, X-Cel)
“Recommending a GP material is a question that comes up with many new GP patients. All the materials have unique applications, so it depends on the patient. The Contamac Comfort, Extra, and Extreme are excellent-performing materials. If a patient has dry eyes, we might recommend one of Acuity’s low Dk materials.” (John Belliveau, Visionary Contact Lens)
Plasma treatment of GP lenses: What is it, and what are the benefits?
“Plasma treatment is a process wherein a finished lens is bombarded with high-energy radio waves in an oxygen-rich environment. Exotic oxygen radicals strike the surface of the lens, dislodging hydrocarbons such as oils that may have been picked up in the manufacturing process. Additionally, the molecules on the surface of the lens are rearranged such that carbon migrates away from the surface while oxygen and nitrogen migrate toward the surface. As a result of plasma treatment, the surface of a lens will become ionized, increasing its ability to attract liquids. These actions combine to make the lens surface more wettable, which in turn can improve the comfort of the lens and reduce fogging problems.” (Kurtis Brown, Menicon)
“Plasma treatment ensures that the lens surface will be pristine and exhibit excellent initial wettability. Although now laboratories use water-soluble compounds, not solvent-based — greatly reducing the possibility of residue-induced poor initial wettability — plasma treatment ensures a very wettable lens surface.” (Keith Parker, Advanced Vision Technologies)
“Think of plasma treatment as an intense cleaning of the lens. The lenses are placed in a chamber with plasma gas. The plasma gas is ionized (negative charge) so it attracts proteins and dirt and lifts them from the lens. And since gas molecules are much smaller than liquid cleaner molecules, the gas can get into the nooks and crannies of a lens to extract the most stubborn deposits. The result is a super clean and very wettable lens.” (John Belliveau, Visionary Contact Lens)
What is Tangible Hydra-PEG, and how is it beneficial?
The Tangible Hydra-PEG surface treatment both reduces surface friction and decreases wetting angle, creating an extremely high level of comfort and wettability. This will not only help provide better comfort, but also reduce deposition on the lenses, which can be very beneficial for patients who do not clean their lenses as thoroughly as recommended. Lenses treated with Tangible Hydra-PEG should be shipped and stored wet for best comfort and longevity. Tangible Sciences also produces both a product-specific cleaner and a booster (coming soon), which will replenish the treatment and extend its lifetime.” (Corey Alvis, ABO-NCLE, ABB Optical Group)
“Tangible Hydra-PEG is a breakthrough polymer coating designed to solve the problem of contact lens discomfort by providing increased lubricity through a highly wettable surface.” (Connie Adam, SynergEyes)
“Hydra-PEG has been a game changer for scleral wearers and dry eye patients! I would recommend it for all lenses, as there are no real downsides. It does make handling the lens more slippery; just remind your patients to cover the sinkhole. And be sure that the patient has access to the approved compliant solutions.” (Robert Powell, Advanced Vision Technologies)
What causes plasma treatment/lens coatings to become ineffective?
“Plasma treatment affects only a very thin layer of the lens, measurable on a nanometer scale. Many common lens cleaning practices involve abrasive components that can wear away this thin layer of affected plastic. Lens care products that contain an abrasive component should not be used with plasma treatment. In-office ‘clean and polish’ services that involve cleaning a lens with abrasive contact lens polish should never be performed on a plasma-treated lens. Proteins and lipids that accumulate on lens surfaces can just as effectively be removed chemically with lens care products for that purpose.” (Kurtis Brown, Menicon)
“If the thin layer of rearranged molecules is worn off, the lens surface returns to the original wetting angle of that material. This is not a problem if the material has a good wetting angle. We have found that cleaners with gritty properties remove the treatment.” (Al Vaske, Advanced Vision Technologies)
“Plasma can become ineffective when the patient is not cleaning and handling the lens properly. For example, placing the lens in tap water or rubbing the lens with dirty fingers. It is important to know the plasma treatment was effective in the first place. We have a test lens that runs through the plasma process each time. After the process, a water droplet is applied to the lens to check for disbursement. If the droplet spreads, then we know we have an effective treatment.” (John Belliveau, Visionary Contact Lens)