contact lens focus

A Euphoric Toric

Lens enhances vision without sacrificing comfort.

Lawrence Lupo, O.D.

Imagine the ability to prescribe a toric lens that not only provides consistent vision regardless of the patient's cylinder power or axis, but also a comfortable wearing experience. You'd be able to reap the rewards of successfully fitting a broad range of astigmatic patients without the fitting headaches historically associated with these patients. I've been doing this for the last year with the Avaira Toric, from CooperVision.

Here, I explain how.

Lens design

Avaira Toric's Optimized Ballast Toric Design features a combination of horizontal Iso-thickness and a wide ballast design to enable a wide range of astigmatism patients to experience enhanced stable vision despite their cylinder power or axis.

Specifically, the ballast band encircles the optic zone completely. This optimizes the lens-lid interaction for orientation as well as comfort.

In addition, the lens' smooth, junctionless surface enables lens stability, and its consistent horizontal thickness across the power range provides enhanced lens stability and minimal rotation. All these design characteristics have facilitated lens adaptation.

Something else to keep in mind: The Avaira Toric is available in one base curve that fits a wide range of corneal curvatures. As a result, switching low cylinder (−0.75D or −1.00D), spherical-wearing patients into this lens enhances their vision without compromising their comfort.

Comfort

Avaira Toric is comprised of silicone hydrogel and features CooperVision's Aquaform Comfort Science technology. This proprietary technology enables the lens to retain water, keeping it moist and eliminating the need for additives, coatings or wetting agents to maintain wearing comfort.

Further, the lens has a Dk of 100, a low modulus design (0.50) and 46% water content.

I believe all these attributes are responsible for the “white eye” appearance seen in those patients in whom I've fit this lens. (As a brief aside, the lens also blocks at least 75% of UVA and 99% of UVB radiation.)

Fitting experience

Recently, a 28-year-old male patient new to my practice presented for a routine exam with no specific complaints. He was recommended to our practice by a current patient.

The patient stated he wore spherical lenses 14 hours a day, and that he changed his lenses every two weeks.

His contact lens-corrected visual acuity was 20/30+ OS 20/30− OD with an over refraction of +0.25−1.00x30 to 20/20 and +0.00−1.25x150 OS to 20/20. His spherical lenses exhibited good movement and position.

Upon questioning, the patient acknowledged end-of-day ocular dryness and decreased distance vision. So, I educated him about the eye health and comfort benefits of new, high oxygen-transmissible materials and the visual advantages of toric lenses available in these materials.

The patient was refit with a low-cylinder Avaira Toric lens. I chose this lens because of its characteristics and its base curve, which allows it to fit a wide range of corneal curves.

The patient presented for follow-up two weeks later. His visual acuity was 20/20 OU. He stated his eyes felt more comfortable and that his vision was significantly improved. The lenses exhibited excellent movement and position. Physiologically, there was no corneal staining, and the bulbar conjunctiva was clear.

The Avaira Toric has removed many of the traditional problems associated with fitting astigmatic patients (e.g. fluctuating vision and discomfort). As a result, it's become a valuable tool in my never-ending quest to give my patients the best contact lenses technology allows. OM