RayOne EMV: Enhancing Vision

Selecting the right intraocular lens (IOL) is always an involved process, but it becomes more complicated in post-laser vision correction (LVC) patients. The post-LVC patient population present unique challenges that can impact IOL power calculations, compromising patient outcomes, such as depth of focus and overall visual acuity.

Here, David A. Goldman, MD, founder and CEO of Goldman Eye (Palm Beach Gardens, Florida, USA), describes how RayOne EMV rises to these post-LVC patient challenges, and further explains how it is applicable to a wide range of cases.

What are the distinct visual challenges of post-myopic and post-hyperopic LVC patients?

When we operate on patients who’ve had prior LVC, there’s always a concern about refractive surprise. And sometimes, laser ablation can leave the patient with some corneal irregularity causing irregular astigmatism, or the patient might have a decentered ablation. In a worst-case scenario, the patient may have corneal ectasia.

What proportion of your cataract patients receive LVC?

I would say about 10 to 15 percent of our patients. It’s more prevalent now. LASIK patients tend to have a milder cataracts compared to the traditional cataract patients, but their visual demands are significantly greater. We’re also seeing younger cataract patients coming in, particularly post-LASIK patients, because they are used to having “perfect vision.” When they experience any sort of dysfunction in their visual acuity, they’re eager to get it corrected.

What are the limitations of traditional IOL options for these patients?

It depends on the shape of the cornea. We perform a corneal topography on most, if not all, patients when they come in as part of their preoperative testing. If the testing shows any forms of irregularity, we lean away from the multifocal class of lenses, for example. In addition, patients can often have halos and glare from their prior LASIK, so if you add an optic that also contributes to glare and halos, you may compound the problem. Obviously, an optic that minimizes those types of dysphotopsias can be very beneficial.

What is RayOne EMV’s role in this space, and what distinguishes it from other IOLs, such as EDOFs?

Diffractive optics separate the light into segments, and in dividing the light they can lose image quality. Unlike many extended depth of focus (EDOF) and multifocal lenses that rely on diffractive technology, RayOne EMV’s nondiffractive optic uses positive spherical aberration to extend range of vision.

This avoids the problems that can arise with diffractive lenses, such as chromatic aberration, glares and halos. A recent study, for example, showed a significantly smaller halo size at all measured degrees except at the 0° position with RayOne EMV compared with Alcon’s Vivity lens when tested with the Aston halometer.

The same study demonstrated that RayOne EMV delivered distancecorrected and uncorrected binocular visual acuity comparable to Vivity across far, intermediate, and near distances (1).

Because RayOne gives you that extended range of vision without diffractive optics, the physician also has a bigger “sweet spot,” a much bigger window to hit the refractive target, when it comes to prior LASIK patients. A lot of patients who’ve had LASIK have had monovision LASIK, and they want to maintain the results of that. With RayOne EMV, you’ve not only got the extra benefit of that bigger sweet spot, but you can give patients extended-depth-of-focus monovision profile without compromising binocular distance vision. If you hit the target, the patient’s dominant eye is going to have distance and intermediate vision, and their near eye will have intermediate to near vision. So, you get the whole complement of vision.

What are the benefits of the design of the RayOne EMV optic?

I would say one of the benefits of the design is that it maintains the extended depth of focus characteristics you get with positive spherical aberration without losing the contrast sensitivity you would find in other +SA lenses. The use of positive spherical aberration shifts the wavefront myopically and works in collaboration with most patients’ naturally occurring corneal spherical aberration. As a result, the change to the IOL’s surface profile is less pronounced compared to other optic designs. (2) In fact, clinical studies have shown that the depth of focus characteristics of the RayOne EMV lens is similar to other EDOF IOLs (3), while the contrast sensitivity is similar to the most popular monofocal IOLs used in the US (4).

What preoperative assessment strategies do you offer cataract surgery patients?

When a patient presents for cataract surgery, we do macular OCT and corneal topography, in addition to the traditional optical biometry. We look at things such as the patient’s current corneal spherical aberration, in case it is significantly high, or if the patient has a wildly irregular cornea, for example, post-LASIK ectasia, keratoconus, or keratoglobus. For those patients I’ll lean more towards a spherically neutral lens.

But if their cornea and macula are within normal limits, then we talk to patients about all their lens options, depending on what their lifestyle demands. In the past, when patients asked for a multifocal lens, they were focused on getting good reading vision. They didn’t drive much at night, so halos were not a major concern. Today, patients have more active lifestyles. They drive more often at night and no longer read print newspapers; instead, they use iPads or computers. As a result, strong up-close near vision is not as much of a priority; rather, they desire distance and intermediate vision. For this reason, a lens such as RayOne EMV is much more preferable.

What are the wider applications of RayOne EMV, particularly for patients with irregular corneas, prior refractive surgery, and other unique visual demands?

For virgin corneas, it is probably the best monofocal lens available in the US market. I like to say it’s a premium lens in monofocal-lens clothing; it gives an exceptional range of vision that is really unparalleled. In my experience, other monofocal lenses that claim to offer extended range of vision often provide only around 0.75 diopters of depth of focus. Clinical studies and our own in-office results show that RayOne EMV consistently delivers about 1.5 diopters of depth of focus, which is an exceptional range for a monofocal lens. If you target distance in both eyes with this, the patient is going to have excellent distance vision and be able to work on the computer without glasses.

What other patient populations might benefit from RayOne EMV?

There are patients with regular corneas, for example, who have keratoconus, but the keratoconus is such that if they wear rigid gas permeable (RGP) or scleral lenses, they will need to continue wearing them after surgery. These patients are great candidates for RayOne EMV, because when they put their RGP or scleral lens back in their eye, they’re going to get the benefit of extended range of vision.

Where would you say RayOne EMV sits within the evolving landscape of IOL offerings?

It is definitely at the top of the mountain. It’s by far one of the easiest lenses to use from a technician and surgical nurse perspective; our surgical techs can prep and load and hand off the lens within seconds. It does not slow us down in the OR in terms of injection. It’s a very simple plunger system that delivers directly into the bag.

Also, because of the design, I’ve seen almost no negative dysphotopsia with RayOne EMV. I’ve used other lenses that have a very high incidence of negative dysphotopsia, and it’s upsetting to have a patient who is 20/20 but is miserable because of something out of the surgeon’s control. But both intraoperative and postoperatively, I think RayOne EMV is better.

For a non-astigmatic patient who is looking to have excellent visual acuity after cataract surgery, I think RayOne EMV is almost always going to be the number-one choice lens.