Article Date: 12/1/2005

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Clinical Experiences with a Silicone Hydrogel Lens
Four practitioners share how incorporating a silicone hydrogel lens into their respective practices has benefited many of their patients.
By Gregg Russell, OD, FAAO

The introduction of hyper-Dk/t silicone hydrogel lenses has created a change in the way eyecare professionals present contact lens options. Many practitioners now say that silicone hydrogel lenses aren't just for continuous wear. In fact, currently most silicone hydrogel lenses are prescribed primarily for daily wear.

The lotrafilcon B material of CIBA Vision's O2Optix lens contains 33 percent water with a permanent surface treatment to assure surface wettability for comfort and resistance to protein deposits, according to the manufacturer. CIBA Vision also says O2Optix provides 62 percent greater oxygen transmissibility than does Acuvue Advance (Vistakon) and more than five times the oxygen of Acuvue 2. O2Optix is available in an 8.6mm base curve in spherical powers from +6.00D to –8.00D in 0.25D steps, and from –8.50D to –10.00D in 0.50D steps.  

To find out how O2Optix is changing the way practitioners approach contact lenses — and how their patients have responded — I spoke with three optometrists about the lens.

It's the Oxygen

Hands down, the hyper-oxygen transmissibility is the favorite lens feature for these eyecare practitioners. Muriel Schornack, OD, of the Mayo Clinic in Rochester, MN, provides her patients with a corneal physiology lesson. She tells them, "The cornea is an avascular system. If it doesn't receive enough oxygen, bad things can happen." Most patients don't consider that a contact lens serves as a barrier between the cornea and oxygen. "If you point out that they're putting plastic on tissue that's living, it gets their attention," Dr. Schornack said.

While Dr. Schornack has heard from many patients that the lenses are more comfortable, to her that's not the selling point. "I want patients to leave with a high-oxygen-transmissible lens. I tell them, 'If this lens works for you, then this is what I want you to wear.'"

Chris T. Miller, OD, from Evanston, IL, shows patients a chart that compares the 138 Dk/t of O2Optix to the low-Dk/t values of HEMA two-week replacement lenses. "Patients are usually surprised because they haven't heard of oxygen transmissibility. I tell them, especially if they wear their contact lenses many hours each day, that this is the best lens for them." Dr. Miller's presentation convinces patients it's a healthy option; a one-week trial has convinced most of his patients that it's also a more comfortable lens, he says.

In my practice, I use a down-to-earth analogy that all patients understand. I tell patients, "Wearing a contact lens that provides higher oxygen levels to the eye compared to standard two-week disposable lenses is like wearing 100 percent cotton on a high humidity day vs. wearing 100 percent polyester."

Expanded Patient Pool

Douglas Weberling, OD, of Bristol, VA, says a lens with greater oxygen transmissibility translates into a greater candidate pool. "I've been able to maintain more patients who complain of dryness symptoms and who are aged 45 and above. Patients who complain that their eyes feel dry after a day of computer use have also loved the lens," he says. He's heard from patients who are ecstatic because they can now comfortably wear their lenses for 14 hours a day. "With low-Dk/t HEMA lenses, these same patients were removing their lenses after just a few hours," he says. "When I provide patients with a trial pair of O2Optix, I send them out with this directive: Compare how these lenses feel at 4 pm. That's when patients really start to notice the difference," he says.

Patients who become frustrated with contact lenses because of dryness, itching and irritated or red eyes are on the brink of becoming contact lens dropouts. That's tough for any practice on several fronts: not only might they drop out of contact lenses, they could drop out of the practice entirely. Not to mention that contact lens patients are generally more compliant in terms of returning for their annual exams than are spectacle patients.

By promoting a change to the O2Optix lens, Dr. Weberling has found that his formerly frustrated patients are now solidly back in the contact lens-wearing column. To boot, they have become enthusiastic boosters of his practice.

The Price Differential

When CIBA first introduced Night & Day, its 175-Dk/t silicone hydrogel approved for up to 30 nights of continuous wear, patients who wanted continuous vision saw the value in the premium price associated with its new technology. With O2Optix, the price differential compared to low-Dk/t lenses is negligible — in fact, it's non-existent when patients redeem the manufacturer's rebate, Dr. Weberling says.

So for patients who may have expressed interest in occasional overnight wear or who noted some symptoms of corneal oxygen deficiency but weren't ready to switch into continuous wear, the O2Optix lens may provide the benefits they want at a comparable price, Dr. Weberling says.

Lens Handling and Wearing Schedule

Dr. Schornack selects this lens for her young patients. "These lenses are easy to handle," she says. "Handling ease — as well as oxygen transmissibility — are benefits to first-time contact lens wearers. If any of my patients have trouble handling other two-week replacement lenses, I recommend a switch to O2Optix," she adds.

Dr. Schornack recommends daily wear for most O2Optix patients. But if they choose to occasionally sleep in their lenses, she feels comfortable because the lenses exceed the 125 Dk/t level recommended for no stromal anoxia during overnight wear.

Dr. Weberling, however, is an active proponent of extended and continuous wear. In his practice, Night & Day is a big success. O2Optix, with its Food and Drug Administration approval for up to six nights of extended wear, has generated interest in his patients who are interested in occasional overnight wear. Dr. Weberling emphasizes the risk factors for infection from extended wear to encourage excellent hygiene and compliance. He makes sure patients know that they shouldn't continue to wear the same lenses — without proper disinfection — during and after an illness and that they shouldn't swim while wearing the lenses. For patients who work or live in a smoke-filled environment, he recommends daily wear or even occasional contact lens wear.

Don't Accept the Status Quo

80
64%
66%
67%
75%
80%
70
60
50
40
30
20
10
  Eyes get red Vision gets blurry/hazy Eyes feel
irritated when
wearing
contacts
Eyes feel
uncomfortable
at end of day
Eyes dry out
Figure 1. Symptoms related to corneal hypoxia and percentage of patients who experience them.

It's simple to introduce O2Optix to new contact lens wearers by telling them it's the newest, most advanced contact lens technology to come on the market. After hearing that, why would a patient ask you to prescribe an older material? "We tend to prescribe O2Optix as an alternative to eyeglasses that's more convenient and equally effective," Dr. Schornack says.

Yet among patients who've worn contact lenses for years, many have come to accept their daily nuisances and discomforts. "Such patients have no basis for comparison," says Dr. Schornack. That's why it's up to practitioners to ask discerning questions that yield more information than a simple yes or no question would.

I recommend questions that specifically address dryness, compliance and overall visual quality. For example, to assess dryness, I ask, "How does your end-of-day comfort compare to the beginning of the day?" Don't simply depend on tear performance tests done in the office because they don't always yield reliable answers, nor do they necessarily provide information about the source of problems with visual performance in contact lenses.

To learn about patients' lens wearing habits, ask open-ended questions such as, "How old is your current pair of lenses?" "How frequently do you sleep in your lenses?" and "How often do you dispose of your lenses?" Document the answers in the patient's chart, especially if he's doing things contrary to your previous instructions. This information can serve as an important segue to explaining other contact lens options.

To better gauge a patient's overall satisfaction with his quality of vision, add a subjective question such as, "Is your vision just as good at the end of the day vs. the beginning of the day?" or "How is your night vision?" This will provide important information.

Create a Buzz

These practitioners share an enthusiasm for new technology — and patients perceive that. Dr. Weberling says, "If I offered patients the same lenses year in and year out, they might as well go elsewhere and price shop. Offering new products has encouraged my patients fill their contact lens prescriptions here." Dr. Weberling also says that when he can reintroduce successful contact lens wear to a patient who dropped out of contact lenses years ago, that generates excitement.

Dr. Schornack says, "For patients who can't or won't change their two-week wearing schedule, these lenses mean that we can offer a healthy lens option. From a professional standpoint, I liken O2Optix to Seldane, the first-generation non-sedating antihistamine. Before that came out, allergy sufferers had the choice of not breathing well or breathing well, but falling asleep. When the new drug came out, practitioners quickly started prescribing it. When HEMA was the best we had, it sufficed. But silicone hydrogel lenses help to decrease the physiologic impact of hypoxia on the cornea."

Other practitioners share Dr. Schornack's view that to continue prescribing low-Dk/t contact lenses may no longer be the best option for some patients. And in doing well for the patient, these clinicians have found that their practices and professional reputations benefit. CLS

What is Corneal Oxygen Deficiency?

Some of the symptoms potentially related to corneal oxygen deficiency include: red eyes, blurry/hazy vision, eyes that feel irritated when wearing contact lenses, eyes that feel uncomfortable at end of day and lens-related dryness (Figure 1). A primary cause of corneal oxygen deficiency is wearing low-oxygen-transmissible contact lenses. In fact, 94 percent of contact lens wearers reported experiencing at least one or more of these symptoms.

Dr. Russell is in practice at the Marietta Eye Clinic. His clinical research interests are in dry eye, aberration control, presbyopia and contact lens design.



Contact Lens Spectrum, Issue: December 2005