Article Date: 7/1/2006

contact lens management
An Improved Rose K
Keratoconus patients get a new contact lens option.


Blanchard Contact Lens' Rose K2 Aberration Control contact lenses have helped me conquer some of the challenges of keratoconus fittings. Many of our patients are referred to us due to failed contact lens wear and are searching for improved vision and comfort. The improved lens design helps me provide the keratoconus patient better overall visual acuity, improved night vision and improved comfort over the original Rose K and other keratoconus lens designs.

Precise fitting

These lenses feature the company's proprietary Systematic Approach to Fitting to guide you through the step-by-step process. The initial step in fitting these lenses is to define the appropriate apical touch (base curve selection), then assess the edge lift pattern. If a change in edge lift is dictated relative to the diagnostic lens edge lift flourescein pattern, you define whether the edge needs to be flatter or steeper relative to the Systematic Approach. If the fit requires a change in edge lift, the Systematic Approach compensates for the peripheral and intermediate curves, base curve and lens power based upon the change indicated at the lens edge. Thus you can maintain the proper apical touch indicated by the initial base curve selection. This fitting approach minimizes the number of successive lenses necessary to reach the final lens parameters. The company provides a desk-top, computer fitting calculator to automate the fit process with a step-by-step analysis of base curve and edge lift selection. This approach guides you in fitting the advanced keratoconus patient, as well as converting those wearing the original Rose K lenses to the new Aberration Control lenses.

The Rose K2

DIAMETERS: 7.9mm - 10.2mm
4.75mm and -8.4mm
Standard: Boston XO, available in any on request
$90.00 per lens warranted.

It's all in the base curve

A posterior, aspheric, conic section replaces the spherical, posterior optical zone of the original Rose K lens. This aspheric, conic section is composed of the posterior optical zone and the first two fitting curves paracentral to the posterior optical zone found on the original Rose K. The larger posterior, aspheric, conic section of the optical zone minimizes on-axis aberration created by high minus power and steep base curves, prevalent in keratoconus lens prescriptions. The lens creates a smaller blur circle image on the retina than the original Rose K. This reduces spherical aberration and improves contrast while reducing flare, glare and halo in dim illumination. Company studies indicate patients may see up to two lines of improvement in visual acuity with power above -10.00D, a result I've duplicated with my keratoconus patients.

Upgrading is easy

I've found that if your patients are wearing Rose K lenses already, you can easily switch them into the new design. You need only specify that you want the new lens when ordering and provide the existing lens parameters. You can achieve new patient fittings using the original fitting set. Apply the same proprietary fitting method. It's my experience that this lens is an excellent option for keratoconus patients, providing the majority of them with improved visual acuity, better contrast and longer hours of comfortable wear.


Optometric Management, Issue: July 2006