CLINICAL

  specialty contact lenses

Combining Vision and Comfort

Consider these recent and “old school” hybrid lens options for patients who have astigmatism or asymmetric cornea.

DIANNE ANDERSON, O.D., F.A.A.O., AURORA, ILL.

The term hybrid seems to be everywhere, ranging from cars, to food and even in our own industry in the form of contact lenses.

Hybrid contact lenses are an inviting option for astigmatic (including against-the-rule, oblique and asymmetrical) and asymmetric cornea patients who require or desire contact lenses, yet are unable to wear GP lenses due to ocular discomfort. The reason: These lenses have a non-toric and rotationally symmetric RGP center, preventing visual fluctuation due to excessive lens movement and rotation, and they are comprised of a soft skirt around the RGP center, which keeps the lens centered and minimizes lens movement with each blink. This allows for stable, consistent vision throughout the day.

Special cornea patients, who comprise approximately 20% of patients, according to the Global Keratoconus Foundation, become loyal to you for all their eyecare needs and refer others when you can successfully fit them. In addition, fitting these patients creates a significant positive revenue stream. (See “Hybrid Contact Lens Billing and Coding,” page 40.)

Here is a look at the recent and “old school”options.

Of note: SynergEyes (www.synergeyes.com) is currently the single global hybrid lens manufacturer (Alcon discontinued their SoftPerm hybrid lens line in 2010).

Note the central vault of the UltraHealth lens in this OCT image.

Recent designs

SynergEyes offers five recent designs:

1. Duette HD. This lens is designed for patients who have or do not have astigmatism. It is empirically fit, using the patient’s keratometry (K) readings and minus-cylinder spectacle prescription.

2. Duette Multifocal. This design is also empirically fit using the patient’s keratometry readings and minus-cylinder spectacle prescription, though also the patient’s eye dominance. It comes in two near zone sizes: small (2.8mm) and large (3.2mm), with a fixed progressive ADD power that cannot be controlled by the practitioner. Generally, the small zone is fit on the patient’s dominant eye, and the large zone is fit on the non-dominant eye. A large zone may be fit on both eyes in patients who have large pupils, and a small zone may be fit on both eyes of patients who have small pupils. (The normal pupil size in adults varies from 2mm to 4mm in diameter in bright light to 4mm to 8mm in the dark.)

3. Duette Progressive. This design has a fixed center near zone of 3mm with progressive ADD powers +1.00D, +1.75D and +2.50D. It is ordered empirically with the patient’s minus-cylinder spectacle refraction and K readings.

Duette lenses are not indicated for keratoconic, post-surgical or irregular astigmatism patients. The empirical fitting approach minimizes chair time, and SynergEyes consultation is available for trouble-shooting so you can achieve successful outcomes with few follow-up visits. The lenses are made of hyper Dk GP materials with silicone hydrogel skirts and deliver all-day tear exchange and lens movement to make them a comfortable and healthy lens option. Lenses reordered for exchange do not need to be returned, which is a time-saving, economical benefit.

4. UltraHealth. This diagnostically fit, reverse geometry design is similar to scleral lenses in that it is fit using vault or elevation rather than base curve. This allows for a flat, centered base curve with a lower power than traditional steep fitting, small diameter RGP lenses. The soft skirt keeps these lenses centered. The result: decreased aberration and improved visual acuity.

UltraHealth has a hyper Dk RGP center with a silicone hydrogel skirt. The hyper Dk values of UltraHealth make it an ideal choice for compromised corneas, such as post-PKP, those that undergo collagen cross-linking and those that undergo semi-circular ring insertion.

SynergEyes recommends beginning the fitting process with the 250F (flat) diagnostic lens and increasing the vault if there is excessive bearing or decreasing it if there is excessive tearpooling beneath the RGP center. The skirt curve can be adjusted to medium (M) or steep (S) for adequate edge clearance.

5. ClearKone. This design is also a diagnostically fit, reverse geometry lens fit using vault or elevation. It works especially well in patients who have very steep, decentered corneal apices.

SynergEyes recommends starting the fitting process with the 250M (medium) diagnostic lens and increasing the vault if there is excessive bearing or reducing it if there is excessive tear pooling beneath the RGP center. The skirt curve can be adjusted to steep(S) or flat (F) for adequate edge clearance.

Old-school designs

The SynergEyes A (astigmatism), KC (keratoconus), MF (multifocal) and PS (post-surgical) designs require diagnostic fitting sets. SynergEyes no longer provides these sets, as the lenses may soon be replaced by the aforementioned designs. But, if you began fitting patients with these lenses, you may reorder their custom, as well as replacement diagnostic lenses.

A shared belief

Drivers passionate about the environment or who worry about escalating fuel prices and culinary enthusiasts who like hybrid foods, such as grapples, likely become lifelong customers at hybrid car dealerships and grocery stores that carry hybrid foods, respectively. Offering hybrid contact lenses to patients who believe they should be able to wear contact lenses has the same effect on practitioners. OM

Dr. Anderson specializes in orthokeratology, keratoconus, post-surgical lens fits and anterior segment disease. E-mail her at dianne.anderson@comcast.net, or send comments to optometricmanagement@gmail.com.