Prescribing for Astigmatism
It Takes One to Know One: Reasons to Fit More Toric Lenses
By Jason R. Miller, OD, MBA
I have been wearing soft spherical contact lenses for 25+ years and have always had between 0.50D to 0.75D of cylinder in each eye. Recently, while performing my daily vision screening (i.e., looking at the chart while I listen to my patient read it aloud), I started feeling like I was just not seeing as well as I used to or as well as I would like to.
I decided to refract myself one morning and found just about the same amount of cylinder in each eye, but I noticed a significant amount of visual acuity improvement with the astigmatism corrected. Subsequently, I decided to refit myself with soft toric contact lenses. It made a big difference in my vision, and my point with this story is that there are most likely many more patients in your practice who would benefit from toric technology.
Studies have shown that the vast majority of patients want to hear about new technology and are willing to pay more for an upgrade once they see what new lenses can do for them (Contact Lens Council, 2007). This creates an excellent opportunity, especially when combined with the fact that there are an estimated 45 million, or one in six, Americans who have significant astigmatism.
The Value of “The Demonstration” Forget visual acuity for a second. Instead, demonstrate to patients their cylindrical correction and just listen to their response. Some practitioners like to use the phoropter for this exercise, while others like to use trial lenses.
This can also be an excellent education session for the patient. Astigmatism is not a very patient-friendly term. This gives us the opportunity to explain that it is not a disease, but simply a refractive error that distorts vision and causes a loss of crispness. This is also an opportunity to rotate the cylinder axis to demonstrate the importance of stability with contact lenses for astigmatism along with the value of the fitting process and your fees.
Advanced Toric Lens Designs
Whether you are fitting a contact lens that is prism-ballasted, periballasted, has dual thin zones, has eccentric lenticularization to reduce the edge thickness and/or back-surface toricity to add stability, if the contact lens rotates easily, the patient will have periods of visual fluctuation. Forced blinking during visual acuity measurements will help identify an unstable toric contact lens. Newer designs allow the lenses to be assessed more quickly, requiring less wait time for the contact lenses to stabilize. Even so, I typically trust my rotation reading more when patients return for their follow-up appointment.
There are not many prescriptions out there for which a toric contact lens is not available. In fact, there are a multitude of toric contact lens options in hydrogel and silicone hydrogel materials, offering more powers ranging from those for low astigmats to those for high astigmats. These lenses deliver dependable orientation, exceptional rotational stability, and consistent fitting success. There are flexible wearing schedules from daily disposable to custom specialty designs that are just as comfortable as their spherical counterparts.
Today's toric lens designs have been refined to provide extremely consistent, clear vision. They do not require significantly more chair time, and cost is no longer a barrier. It is time we all started fitting more of our astigmats with toric lenses. CLS
For references, please visit www.clspectrum.com/references.asp and click on document #183.
Dr. Miller is in a partnership private practice in Powell, Ohio, and is an adjunct faculty member for The Ohio State University College of Optometry. He has received honoraria for writing, speaking, acting in an advisory capacity, or research from Alcon, Argent Media, Aton Pharma, CooperVision, and Hoya. You can reach him at email@example.com.