A Systematic Strategy to Fit Toric Multifocal Contact Lenses

Imagine this scenario: A patient with presbyopia and astigmatism enters your practice inquiring about multifocal contact lenses. How do you respond? Here are some reactions from industry professionals who were asked the same question:

• I won’t fit them. Multifocal contacts don’t work for these patients because the lenses typically end up being blurry at all distances.
• I always manage to talk patients out of multifocal torics.
• I’ve never fit toric multifocal contact lenses and I don’t intend to start. It’s not worth the hassle.
• Monovision prescriptions are the way to go.
• I would recommend distance contact lenses and reading glasses for close activities.

This candid feedback highlights the frustrating experiences many eye-care professionals have had when attempting to fit toric multifocal contact lenses. So, you might be surprised to learn that a growing number of presbyopic astigmatic patients are being successfully fitted with multifocal contact lenses…and that eye-care practitioners are finding the process to be simple and hassle-free.

At SpecialEyes, we share your goal of successful patient outcomes, and we understand how you feel when your efforts to fit toric multifocal contact lenses simply don’t pan out. That’s why we began to examine our internal data in search of trends to help practitioners reduce frustration and improve patient outcomes. We discovered that the practices with the highest success rates have a few things in common. One commonality is a streamlined, multi-step process in which the eye-care professional uses expertise to obtain solid measurements and exam information. Our most successful practitioners then use this information and partner with SpecialEyes to customize the multifocal optics according to the patient’s specific visual needs and pupil size. To put it simply, these practitioners are putting the science back into multifocal toric contact lens fittings. The case study below is a great example.

Case Study
A practitioner called SpecialEyes to order a trial pair of SpecialEyes 54 Multifocal Toric lenses. Upon speaking with a member of our consultation team, the practitioner provided the following information:

Keratometry Readings
OD: 44.75/45.25
OS: 43.25/45.0

Manifest Refraction
OD: -.25 -1.25 x099 (+2.50 add)
OS: -.25 -1.25 x011 (+2.50 add)

Pupil Size
OU: 3.0mm photopic; 5.0mm mesopic
Measured with ruler
Used average 4.5mm pupil

Trial #1
Using the information provided, the consultant designed the following trial lenses:
OD: 7.9 BC/14.5 Diam. -.25 -1.25 x099 (+2.50 add) 2.0 N/C, 3.5 I/Z
OS: 8.2 BC/14.7 Diam. -.25 -1.25 x011 (+2.50 add) 2.0 N/C, 3.5 I/Z

During the dispense appointment, the practitioner observed that the lenses had good centration, optimal limbal coverage, and no rotation. He noted that the lenses had a little less movement than he would like to see. Given the patient’s history of dryness, the doctor was concerned that she might have comfort issues with longer wear time.

With the first pair of trial lenses, the patient stated that she loved her near vision (20/25) but was unhappy with her distance vision (20/50 OU). The practitioner then performed an over-refraction with loose lenses and found that a -.75 at distance improved her distance vision to 20/20 but ultimately ruined the near vision she loved. When he communicated these details to our team, his SpecialEyes consultant recommended flattening the base curve by .1mm and decreasing the peripheral zone to 3.0mm.

OD: 8.0 BC/14.5 Diam. -.25 -1.25 x099 (+2.50 add) 2.0 N/C, 3.0 I/Z
OS: 8.3 BC/14.7 Diam. -.25 -1.25 x011 (+2.50 add) 2.0 N/C, 3.0 I/Z

Trial #2
With the second set of trial lenses, the practitioner noted improved movement on the blink, and the patient was able to achieve 20/20(-) at both distance and near. The practitioner instructed his patient to wear the lenses and report back with any comfort or vision issues. Shortly afterward, the patient called his office and said she loved her new lenses and requested the remaining lenses for her full-year supply.

Explanation of Zone Change
Many times, we find that suboptimal visual acuity can be attributed to pupil size and the manner in which the multifocal optics are distributed. SpecialEyes consultants are trained to decipher which change will be most appropriate: a multifocal zone change or a power change. In this scenario, the patient was taking a lot of extra minus power at distance in the over-refraction, which hurt her near vision. Generally, this is a sign that the peripheral zone (the point at which the near-center lens reaches full distance power) is too large and the patient is not getting enough area of distance optics over the pupil. By decreasing the size of the peripheral zone, this patient was able to experience improved distance vision without sacrificing the near vision she loved. Our ability to customize the multifocal optics based on the patient’s pupil size and visual needs is what makes the SpecialEyes 54 Multifocal unlike any other soft multifocal design on the market.

Dashed circles represent the center-zone diameter and peripheral-zone diameter values. The near-center zone diameter is comprised of full near optics. At the edge of the near-center zone, the lens then starts to transition or progress in power throughout this intermediate area, until reaching the peripheral-zone diameter. The peripheral-zone diameter is the point in the lens at which we reach full distance power in a near-center design. The lens remains at full distance power from the peripheral-zone diameter throughout the remainder of the optic zone.

Conclusion
The real hero of this case is the practitioner. First, he selected a patient with high motivation and realistic expectations. He then ensured that he had carefully obtained all of the measurements needed for the initial design. Once the lenses were on the eye, he conducted a thorough examination and recorded details on the lens fit, visual acuity, and over-refraction results. Finally, he communicated his findings to our team and trusted suggestions from the consultant. By taking a systematic approach from start to finish and prescribing a lens with custom optics optimized for the patient’s specific needs, the practitioner was able to easily satisfy his patient in just two trial lenses.

If you have been searching for an easier way to fit toric multifocal contact lenses, consider implementing our Multifocal Fitting Strategy and prescribing the SpecialEyes 54 Multifocal Toric.