CONTINUOUS WEAR
Realizing the Benefits of Continuous Wear
If your patients want continuous vision and they are good candidates, then you will both appreciate the perks of continuous wear. Try it and you'll see.
By Robert D. Buffington, OD, FAAO

In our current fast-paced and busy world, many of our patients demand continuous vision, which exists in several forms: orthokeratology, refractive surgery or continuous wear contact lenses. Switching your patients from daily wear lenses to 30-day continuous wear (CW) contact lenses may hold unlimited potential for the growth of the contact lens segment of your practice.

In fact, we now have two modalities available for our patients, each approved for 30 nights of CW. CIBA Vision's Focus Night & Day (lotrafilcon A) soft lens was first approved, and now we also have Menicon's Menicon Z (fluoro-siloxanyl styrene) GP lens. I'll outline some tips that I've learned after fitting more than 15,000 CW patients.

What Makes a Good CW Lens?

1. An exceptional lens material is where it all starts. Both the CIBA Night & Day and the Menicon Z lenses use hyper Dk materials and as such, transmit enough oxygen to the cornea in most cases for optimal corneal health. This guarantees excellent conditions for overnight wear.

2. Comfort, determined by an excellent lens design, is critical. It is sometimes difficult to have good initial lens comfort with a GP lens, but the Alpha design made from the Menicon Z material has proven exceptionally comfortable.

Our practice participated in the FDA clinical trials to approve the Menicon Z lens material for 30-day CW. The protocol for the study involved refitting existing GP wearers with the Menicon Z Alpha design and then beginning CW. No one reported any serious adverse events in the entire year-long study. A large percentage of the study subjects commented that the Alpha design was much more comfortable than that of their prior GP lenses. Along with the Alpha design, our office fits a large number of CIBA Night & Day lenses. Patients express their satisfaction with the lens design and comfort of the contact lens.

3. Reproducibility of each and every lens is a must. Without high manufacturing standards, continuous wear would not be possible. The beauty of the Menicon Z Alpha design is the consistency of its edge profile. This result is much more difficult to achieve with a rigid lens than with a soft lens because of the current high technology used in manufacturing soft contact lenses. Therefore, the reproducibility of the CIBA Night & Day soft lens is excellent.

Evaluating Patients for Continuous Wear

The key factor for success in CW fitting is selecting the proper patients. The most important factor when choosing a patient is his tear composition. You must assess the tear break-up time (TBUT) and tear volume before you can recommend CW to the patient. Patients who have a fast TBUT or low tear volume are generally not good candidates for comfortable CW. It's best to avoid making any recommendations as to what type of lens would serve a patient best, or even bringing up the subject of CW, until you complete a detailed evaluation of the tears.

Evaluate the patient's cornea and the lids to make sure they are free of any surface disease or infection. Armed with this information, you can explain to your patient how his tear composition and overall ocular health can affect his ability to wear continuous wear contact lenses successfully for extended periods of time.

Deciding What Lens to Fit

Assuming that tear composition and volume meet the requirements for CW lens fitting, you can then proceed to the next step: deciding which lens to fit.

An important part of lens selection is discussing lifestyle with the patient. Make sure patient expectations are clear and realistic so you know which of the two lens modalities will likely be most successful. Here's what you need to know about each lens.

The Menicon Z Alpha GP lens The Menicon Z 30-day continuous wear lens material can be made into the Alpha rigid lens design. The Alpha is generally a good first lens of choice, and is easy to fit. Start by choosing a base curve that is 0.50 diopter flatter than the flattest K reading and adjust the power accordingly. You can do this from a small fitting set, or you can order the lenses from Con-Cise Contact Lens Company, Diversified Ophthalmics, ABB Optical, Firestone Optics or TruForm Optics and fit them empirically. The Alpha design is forgiving and patients will find it comfortable even without any lens modification.

Besides ease in fitting, the Alpha boasts other advantages as well. There is a wide range of parameters to choose from. Because a GP generally masks astigmatism on the cornea, the optics are better than that of a soft lens. This optical superiority makes a rigid lens the better choice for monovision correction. In the event that there is residual cylinder after overrefraction, you can order front, back and bitoric designs in the CW Menicon Z material.

We fit many young people in our practice, and attempting some degree of myopia control with the Menicon lens is worth trying. This is also an excellent lens for orthokeratology on low myopes, and when combined with CW you will get even greater flattening of the cornea, creating a nice night retainer.

The Night & Day soft lens In some situations the best lens choice for successful CW is a soft lens. For example, some existing soft lens patients may want CW but would prefer to stay in hydrogel lenses. As with any soft lens, Focus Night & Day lenses provide excellent initial comfort for those patients who may be squeamish or who have difficulty adapting to a GP contact lens. Patients who have active lifestyles as well as younger patients who participate in contact sports will benefit from the safety aspects of wearing a soft contact lens as opposed to wearing a GP contact lens.

You should also consider each patient's working environment. Those working in construction and others who have outdoor occupations may appreciate the fact that dust, dirt and other foreign bodies in the eye are less noticeable when wearing a soft contact lens. For these patients, the logical choice for CW is the Night & Day lens. Many patients enjoy wearing contact lenses for social use with the option of occasional periods of CW. CIBA's Night & Day lenses fit this patient population well.

Learn to Fit with Finesse

When prescribing CW lenses for a first-time wearer, consider the following guidelines to ensure a smooth and successful transition:

• When fitting a new Menicon CW patient, I recommend using Claris contact lens care products (distributed by Advanced Medical Optics, Inc., marketed by Menicon) because of their compatibility with the Menicon Z material.
• Start the wearing schedule at six hours each day and increase by two hours each day until the patient achieves full-time daily wear. It is helpful to have a contact lens technician call the patient 10 days after the initial dispensing to assess how well he is doing and to solve any problems or issues he may have before his first return visit.
• The patient should return to the office three weeks after the initial dispensing. If at this visit the comfort is good at the end of the day, wearing time is proper and the vision is correct, then it is time to start CW. Advise the patient to sleep in the lenses that night and to return to the office wearing the lenses in one week. I prefer to see the patient at this one-week visit rather than the morning after the first night of CW.
• Schedule the remaining visits for three weeks later, one month from then and again in three months to monitor corneal and overall eye health and to verify the condition of the lenses. Preappoint the patient on the final visit for his annual eye examination. At the time of the annual examination, carefully inspect the condition of the lenses, especially with your radiuscope.

You can use the real image to assess any buildup of mucus or protein that may have occurred during the year of CW. Buildup, scratches, cracks or chips, lens warpage or any other findings at the annual exam that you cannot cure with a simple polishing indicates that a replacement contact lens may be necessary.

In general, depending on the condition of the lenses, a yearly replacement schedule is best for the corneal health of the CW Menicon Z patient.

• Fitting the Night & Day lens is straightforward and requires little chair time. It is available in two base curves: 8.4mm and 8.6mm. Start with the 8.6mm base curve and let the lenses settle for about 10 minutes. Assess lens movement, lens centration and overall coverage with the slit lamp. If you notice excessive movement on vertical gaze or a lack of centration, then change to the steeper 8.4mm lens.

If the visual acuity is good and the patient is pleased with the comfort, then have your technician dispense the contact lenses to him. Regardless of which lens you prescribe for CW, the follow-up schedule remains the same. However, if the patient is wearing the CIBA Focus Night & Day lens, then instruct him to replace the lenses once a month and warn him of the potential risks and health hazards of over wear.

CW is a Win-Win Situation for Your Practice

Patient reaction to 30-day CW has been very positive. Many are not even aware that this option is available. We have found that CW patients (especially those wearing the Menicon Z lens) are the most loyal patients in our practice and they create many referrals. The patients whom we fit in either lens enjoy and appreciate the continuous vision they achieve from 30 days of consistent wear. Because many patients and practitioners are hesitant to face the risks of laser surgery, it's great to have these two competitive options available.

I believe you can prescribe either Menicon's Menicon Z Alpha lens or CIBA's Focus Night & Day soft lens with the confidence that your patients will reap the benefits of CW and continuous vision without sacrificing excellent corneal health. Make the switch from daily wear to CW lenses, and you will exceed your patients' expectations while increasing your practice's bottom line. This, of course, translates into a great income stream.