March 3, 2025
MARKHAM, Ontario, Canada — At THE Myopia Meeting held in MARKHAM, Ontario, Sunday, December 8, 2024, Douglas P. Benoit, OD, FAAO, presented a clinical review on behalf of Visioneering Technologies Inc (VTI). His presentation focused on the science behind the NaturalVue Enhanced Multifocal design.
Breaking Down the Design
Dr. Benoit began his presentation by breaking down the design of VTI’s NaturalVue Enhanced Multifocal contact lens.
“The NaturalVue lens is a very unique design,” Dr. Benoit explained. “The lens has a large V pattern; at the center of the lens is the distance correction, and at the top, there’s 8.00D of plus at a 6.00 mm diameter. So, moving from that low point of the V, all the way up to the 6.00 mm area, the lens is generating roughly 8.00D of plus power. That’s more than enough plus power for what your patient needs, whether they’re a myope or a presbyope. The cool part is if you’re generating 8.00D when you have a 6.00 mm pupil, you’re not losing everything if the pupil size gets smaller. So, if you have a 3.00 mm pupil, you’re still getting roughly 2.50D of plus power. Some other lens designs aren’t going to give you that plus power with a smaller pupil. And if your youngster is outside getting the outdoor activity that they’re supposed to get every day, or if they’re reading under very high light, their pupil may be very small — around 3.00 mm.
“There are different designs of multifocal lenses and lenses for myopia progression control out there. Typically, they have a ring-type arrangement, which creates two different focal points. So, you have your near focal point generated by one ring, and then you have your distance focal point, which is generated by a second ring. Light entering the eye is split roughly 50/50 between the near and the distance focal points. The light that goes through that near focal point continues onto the retina. That’s going to give you a halo on the retina around your primary focus, and because that halo has the same intensity as the primary focal point, there’s a lot of interference. That makes it very difficult to get patients to use a concentric design when the add power is above +2.50D because there’s just too much interference.
“Now, contrast that with the extended depth of focus (EDOF) channel that’s created with the NaturalVue Multifocal lens,” Dr. Benoit explained. “You do have a halo that’s created, but it’s spread out over a much larger area, and it’s incredibly diffuse, so that the plus is there, but it’s not concentrated heavily around that focal point. The plus power is ignored by the brain and visual system until the patient needs whatever power they require. In a youngster, that’s very important, because we want to cover as much of the retina as we can with that peripheral plus to pull in those peripheral light rays and decrease the stimulus for axial elongation.
“With the NaturalVue Multifocal, we’re creating this very long thin EDOF channel. If your image falls along this EDOF channel, it’s going to be corrected. Because of all the peripheral plus that’s in this lens, it pulls the peripheral light rays inside the retina and decreasing the stimulus for axial elongation in myopic youngsters. But you also have a lot of plus power that’s there for your presbyopic patients. If the add power that they need falls along this channel, you’re going to get seamlessly clear vision from distance to near.
“Another plus to this lens, and it’s something that VTI has an indication for with the FDA in the U.S., is that if the patients’ astigmatism meridians’ focal points fall along that channel, you will be correcting the vision, not just masking the astigmatism.
“The beauty of this design, aside from having all that plus power, is that when properly fitted, patients get excellent distance vision as well as the near vision and/or intermediate if you happen to have a presbyope, and you don’t lose stereopsis. You’re getting all the benefits of that high plus power and none of the negatives. As I mentioned before, if you’re talking about astigmatism, if your two meridian focal points fall on that EDOF channel, you are going to correct that vision so we get great clarity. I had a colleague in England who told me at a meeting last year that she had a patient with 5.00D of astigmatism and she was able to get a 20/20 vision for that patient, which is phenomenal.
The Fitting Process
After discussing the design of the NaturalVue Multifocal lens, Dr. Benoit then transitioned into sharing the fitting process for the lenses.
“A lens like this with all this power needs a slightly different fitting process,” Dr. Benoit said. “It’s not difficult, but it is different. The key here is to forget what we know about other multifocal designs. Stop pushing plus. You need to maximize the distance vision, and it really is as simple as getting clear distance vision like you would with a single vision distance lens. You start by doing your best corrected spectacle refraction, put up the DuoChrome, and get the patient one-click into green. We’re biasing towards minus, and the reason for that is because of all the plus that’s built into that lens. At that distance central point, when you move five microns away, you start building plus power. So, you need to be able to cut through that extra plus in order to put the foveal focus where it needs to be, so the visual cortex and the brain can do their work.
“As we know from a number of other studies, if you do not correct your patients fully, under-correction can make the myopia worse. We don’t need to worry about giving patients a little bit more minus when we’re doing this fitting — it will not create issues. Think of it as the Jessen factor when you’re fitting OrthoK. It’s a compensation factor. That’s all it is.
“Overall, the fitting process is very straightforward. As I said before, you need the best corrected spectacle refraction, put up the DuoChrome, and go one click into the green. Then, you put the information into the NaturalVue Quickstart Calculator. The Calculator can be on your desktop, or it can be on your phone, and it’s available in both app stores. I would encourage you to use the Calculator even for folks that don’t need vertex correction for the simple reason that the Calculator will bias towards minus for you.
“For instance, if you have a -0.75 cylinder, and you take half of that to do a spherical equivalent calculation, you can’t take -0.375. It doesn’t exist. Normally, we would go with a -0.25. With this lens, that’s the wrong way. So, the Calculator will go -0.50 and add that to your sphere to give you the proper starting power. There are a number of studies that look at how much minus you can give a youngster that has an XO deviation/exotropia in order to straighten the eyes to give them better function. The concern is if you’re giving them more minus than their prescription needs, what are you doing to their refraction? Well, most of those studies have shown until you get beyond 2.00D over what their distance correction is, you’ll not have any influence on their myopia change. So, don’t worry about 0.25D, it’s not going to be a bother.
“The key is to explain to the patient what this lens is doing. You don’t have to get into great detail, but you should tell them that it’s a totally different design than what they’re used to, and it may take their brain a little while to get used to this. But once it does, it’s going to be fantastic. At first, it may seem a little bit odd. Presbyopes will tell you that the distance looks great, but they may have a weird feeling in the periphery that lasts for a few hours to a day or so depending on the patient. For me, it took about three days. Once you get to that point, the vision’s clear, and there is no peripheral issue whatsoever. If you follow the fitting guide, you’re going to get great results.
“We have done a number of retrospective studies with the NaturalVue Multifocal lens. The six-year data that was published a couple years back showed that kids that were progressing about 1.00D before being put into the NaturalVue lens, over the next six years, 91% had a 0.25D change or less in the entire six years. That seems like it’s kind of unbelievable, but to quiet critics, VTI has a randomized controlled trial. We are just now finishing the second year. The first-year data showed pretty much the same thing. The NaturalVue Multifocal had a 89% decrease in refractive error change, and a 61% decrease in axial length change in that first year compared to the control lens. So, this lens has very robust performance under different modes of practice and populations. It backs up what we’ve seen in the real world, and I think anyone that tries this lens is going to be very, very happy with the results.”
Dr. Benoit was compensated for his time in preparing this article.
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