June 20, 2023
When it comes to fitting presbyopes, custom soft multifocal contact lenses are an option that is often overlooked. Specifically designed for each individual prescription, custom lenses give the patient the soft lens experience with optics to correct for most patients. These contact lenses have more opportunities to enhance the comfort and vision of the lenses by changing parameters like lens diameter, material, optic zone size, or multifocal optics. They do require a little more education, depending on the lens design, but they will ultimately provide a satisfactory fit.
All custom soft multifocal lenses will begin with an updated refraction at the time of examination, similar to other multifocal evaluations, as described here: “Finding a Contact Lens Solution for Every Presbyopic Patient.” Measuring average keratometry readings, horizontal visible iris diameter (HVID), pupil size, and dominant eye is also important. Keratometry readings are usually captured on your autorefractor but can also be obtained from a topographer. HVID can be measured by hand using a ruler or also obtained by most topographers. The dominant eye can be determined using two methods: sighted or blur. In the sighted method, the patient is instructed to look through a hole created by their hands, trying to find a target from the practitioner. The blur method uses a loose lens (+1.50D or +2.00D), alternating eyes to see which is better. The patient will report worse binocular vision when the loose lens is over the dominant eye. If the patient reports that binocular vision is equally blurry no matter which eye is blurred, then revert to the sighted method.
Finding the Right Design is Key
Knowing the types of designs among the various lens options will help guide you in choosing an option for the patient. Is the design center distance or center near? Can it be either? What parameters can be changed, and how does it affect the vision? What measurements are required to get an accurate, empirical fit?
For example, changing the size of the center optic zone can dial in the vision and reduce dysphotopsias such as glare, halos, and monocular diplopia or ghosting. For toric multifocals, you can adjust the amount of prism ballast to improve stability throughout the day to minimize any fluctuations in vision. Cylinder powers often go up to -8.00D or more in -0.25D increments, and axes can be ordered around the clock in 1ᴼ increments. Add powers are also often available higher than +2.50D.
Many companies offer different material options in their presbyopic designs to help with adjusting patient comfort. Because of the incredibly large amount of parameters available and amount of variables that can be adjusted, custom soft (toric) multifocals are excellent options for patients who either fall out of range of or who have tried and failed standard soft options.
Let a Consultant Be Your Guide
There are a large variety of custom multifocal contact lenses, but the important step is working with a consultant to gain confidence in prescribing. Each lens manufacturer has a consultation team there to guide you through the process with specific knowledge of their product portfolio. The consultants are there to give support to help with troubleshooting, lens design questions, as well as information regarding order status.
As for finding the right partners, reach out to your current distributors to see if there is one within their portfolio. Other industry vendors have specialty lens divisions within the major manufacturers that have entire departments dedicated to special order lenses.
Finally, there are other companies that only manufacture custom lenses. Networking at optometric conferences, reading advertisements within trade journals, and reaching out to industry representatives at existing companies are some of the ways that we’ve found our specialty lenses of choice.
Custom soft multifocal contact lenses offer a unique lens specifically made for the patient’s best visual outcome. Through the years of using these different lenses, we’ve been able to give patients an elevated experience to give them the comfort and vision other lenses aren’t able to achieve.
