Last week we discussed how even satisfied patients have opportunities to improve their vision and lens wearing experiences when introduced to the latest advances in technology. To read that discussion visit www.bausch.com/enewsarchives. Today we’ll address our fourth topic in the series:

Settling time, return to orientation, centration, parameter availability and handling are all factors that individually affect a successful fitting. However, it’s the interaction of these variables working well together that can create the optimal lens fitting experience.

• Settling Time – Patients should wear any toric contact lens for 10-20 minutes for adaptation and tear film stabilization. Do not rush this settling period because the lens positioning, movement and translation all aid in fitting success.
  
  
• Return to Orientation – A well-designed toric lens will adopt a repeatable orientation position on a wide range of eyes. The lens settles and maintains a stable orientation position because of the influence of the lids. A quick orientation means crisp visual quality results right away. Once placed, toric lenses must stabilize and reorient immediately after patients rub or blink their eyes.
  
  
• Centration – Centration is the main determinant of high contrast vision performance. Centration plays an important role in aligning the lens optics with the visual axis creating better optical quality for better visual acuity (see Figure 1). A well designed lens will achieve full centration and provide better optical quality. It is another factor which contributes to an easier fitting experience.
  

• Parameter Availability – The range of powers available to eye care practitioners needs to be comprehensive. Patients with all levels of cylinder and axis need options. The ideal approach to fitting is to dispense lenses at the initial visit from an extensive trial lens dispensing set. Such an approach is becoming standard practice with toric soft lenses as with spherical lenses. Clearly, this saves on administration and avoids at least one extra appointment.
  
  
• Handling – Lenses need to be easy to hold and manipulate when inserting them on to the eye. Patients will find that silicone hydrogel lenses are easy to insert and remove and that it's simple to tell if they're inverted. Silicone hydrogel lenses generally  "stand up" on their finger and don’t "roll up." Different designs can present different handling characteristics, so note which works best for your patients.

The Bausch & Lomb PureVision® Toric lens is an example of one of the latest lens technologies that puts all of the key fitting factors together. In two separate studies the PureVision Toric lens was rated by eye care professionals as easy to fit. The first study, conducted in 117 sites in 8 countries, showed 99% of professionals agreed PureVision Toric lenses were easy to fit.¹ In the most recent study the lens was overwhelmingly preferred for ease of fit when compared to another leading toric lens (see Figure 2).

In a separate study comparing the same brands, over 100 patients' centration accuracy was measured. Here, 90.6% of the Bausch & Lomb PureVision Toric wearers experienced excellent, fully centered lenses (see Figure 3).

Soft toric contact lenses were once considered difficult to fit, but with today's sophisticated lens designs that has changed. Due to optimized stabilization methods, a wide range of available powers and advanced lens materials for handling - fitting today’s toric lenses is far easier than it once was.

For more information about the new Bausch & Lomb PureVision Toric lenses, go to www.bausch.com/demandstability. To read past issues of the Just the Fact series visit www.bausch.com/enewsarchives.

¹ Results from a Q4 2004 clinical evaluation conducted at 117 sites in eight countries in which 900 astigmatic patients wearing spectacles (n=119), spherical contact lenses, or toric contact lenses (n=629) were fitted with PureVision Toric lenses. After using the PureVision Toric lenses for one month, patients completed a forced choice questionnaire in which they chose product preferences for specific attributes. Practitioners provided lens fit, slit lamp evaluations, and product performance rating information at each visit.

² Results from an independent 2006 survey of 95 eye care professionals performed by Directive Analytics. Participation was limited to eye care professionals who had fitting experience with all brands of silicone hydrogel toric lenses available at the time of the survey. Study results represent eye care professionals’ ratings among those with a preference.

³ A total of 18 eye care professionals evaluated 107 patients wearing ACUVUE Advance for Astigmatism for fit/orientation and visual acuity at initial visit. These patients were then fitted with PureVision Toric lenses and equivalent assessments were made at the initial fitting and after two weeks of wear.

© 2007 Bausch & Lomb Incorporated. ®/™ denote trademarks of Bausch & Lomb Incorporated. Other brand/product names are trademarks of their respective owners.

Case Study

Dr. Benjamin Chudner of Bremerton, WA practices in a clinic where he’s constantly finding and fitting astigmatic patients in toric lenses.

“I had one patient who was told she couldn’t wear contact lenses. She was told they were ‘not for her’ because her prescription was mainly astigmatism with a low sphere component: –0.25 sphere with –1.25 cylinder in the right eye and a plano sphere of –1.0 cylinder in the left eye. The patient was disappointed. She would’ve much rather have worn contact lenses instead of glasses.

Even I used to think that patients had to have a ‘high amount of astigmatism’ to successfully wear toric lenses. The concern was rotation. Any little bit of it would cause intermittent blurring in the patient’s vision.

With the latest toric lens designs, I’ve found I’m able to fit nearly all of my astigmatic patients.  I was really pleased to be able to offer this new patient the opportunity to get into toric lenses.

I picked the Bausch & Lomb PureVision Toric because of the great stability. Plus, I knew the settling time would be quick. As I expected, the lenses settled right away. I fit her in a pair of trial lenses and let her tear film stabilize. And that was all it took! She was sold! Thrilled, and seeing 20/20 in each eye.

With a fast settling time and successful orientation of the lens right while she was here in my office, I knew she’d be smiling when I saw her again in two weeks. She’s been happily fit in the Bausch & Lomb PureVision Torics ever since.”