Mixing Multifocal Cataract Lenses
(ReZoom and AcrySof IQ ReSTOR)

By Marilyn Haddrill

[Editor's note: AllAboutVision.com editor Marilyn Haddrill shares her cataract surgery outcome following implantation of a ReZoom multifocal lens by Abbott Medical Optics (AMO) and an AcrySof IQ ReSTOR multifocal lens aspheric version by Alcon. She also underwent limbal relaxing incisions, which slightly flattened her eye's surface to correct mild astigmatism in her right eye. She wrote her account in July 2007, about six weeks after her final cataract surgery. Read the end of the article for an update that describes outcomes two years later.]

After cataracts began significantly affecting my night vision in early 2007, I chose cataract surgery with implantation of a ReZoom (Abbott Medical Optics) in my right eye and ReSTOR (Alcon) aspheric version in my left eye for several reasons:

• I was aware of professional journal discussions among cataract surgeons indicating that certain qualified candidates potentially could benefit from a fuller range of vision when the ReSTOR and ReZoom multifocal lenses were combined.
• Most importantly, my cataract surgeon (Dr. William Fishkind of Tucson) recommended this approach.

Just before cataract surgery, I was highly myopic at -7 diopters in my right eye and -6 diopters in my left eye. I had worn glasses for nearsightedness since I was six years old and could never see the "big E" on the chart without correction. With presbyopia (inability to focus at all ranges) and cataracts added to high myopia, my visual function was degrading rapidly.

Now, since cataract surgery on my first eye in late May of 2007, I have not worn glasses at all. I see adequately at all distances, especially with reasonable lighting. Intermediate vision for computer work remains a bit fuzzy, though I am still adapting. Several weeks out from my second eye surgery in mid-June, my outcome was this:

• Both eyes: 20/20 distance, 20/15 near.
• Left eye (ReSTOR): 20/20 distance, 20/15 near.
• Right eye (ReZoom): 20/20 distance, 20/20 near.

At this point, I am a solid fan of mixing the two lenses. You might consider this option if you are qualified and motivated, and your eye surgeon thinks it's a good idea. Also, you must be prepared to spend roughly between $4,000 and $5,000 of your own money to pay for both premium lenses, which health insurance and Medicare usually will not cover. However, most health insurance and Medicare will cover basic costs of cataract surgery.

Your expectations also must be realistic. You are unlikely to see with absolute crispness or even fullness in all "real world" situations outside the well lit room where you undergo your eye exam. But in certain situations, such as daytime in the outdoors, you might (as I did) notice significant vision improvement, even beyond what was provided by the usual eyeglasses or contact lenses you wore previously.

Multifocal IOLs aim to offer a full range of vision (near, intermediate and distance), as in this simulation supplied by AcrySof IQ ReSTOR and Dr. William Fishkind.

Why Mix the ReZoom and ReSTOR Multifocal Lenses?

Not surprisingly, the two competing companies that market these two lenses think mixing them together is a bad idea. So do some cataract surgeons, based on discussions in professional journals.

But now that I've experienced these results, I fully understand why some cataract surgeons take this approach with qualified candidates. Each lens refracts light in a different way. Images are processed differently, depending on the way the "zones" are set up on each lens to enable simultaneous vision at near, intermediate and far ranges. This means that each lens performs differently in certain circumstances.

Ocular Surgery News and other trade publications recently have quoted eye surgeons who are interested in seeing companies develop pairs of intraocular lenses, with each lens having different characteristics. Once implanted during cataract surgery, the combined strengths of each lens then would contribute to better vision at all distance ranges.

Eye surgeons say this approach, creating a type of modified monovision, would take some of the "guesswork" out of using two different types of intraocular lenses, particularly when it comes to mixing and matching lenses manufactured by different companies.

Benefits I've experienced from the two lenses include:

• ReZoom: I could not work at the computer without the ReZoom eye, which so far is superior (though not perfect) for intermediate vision. In some situations, ReZoom is better for distance vision. But in other situations (primarily in low lighting), the ReZoom is less effective at distance. Sometimes the ReZoom eye sees better for near vision, depending on the lighting and circumstances. The ReZoom lens is fine for normal reading, but so far does not work at all for extremely fine print. Still, with the ReZoom, I see 20/20 at near.
• ReSTOR: I could not function as well as I do in low lighting without the IQ ReSTOR lens, aspheric version. As an example, I can see digital clock displays in the dark with absolute clarity through my IQ ReSTOR eye. Television watching is best with ReSTOR. I credit my IQ ReSTOR eye with easily spotting a rattlesnake on the trail — two different times — in dark, low contrast conditions of late evening. The IQ ReSTOR lens provides exceptional ability to see the finest of fine print, but only in reasonably good lighting. The IQ ReSTOR is not so good for computer work (so far), but has actually improved in the intermediate range as I've adapted to both lenses. The ReSTOR, like ReZoom, is a great distance lens.
• ReSTOR and ReZoom Together: The IQ ReSTOR and ReZoom are learning to work together as a team. Actually, it's more like I'm adapting (eye to brain) to the two lenses and how they work together. Some cataract surgeons are reluctant to implant two different lenses because a few people (like me) can't resist constantly "testing" each lens under different conditions, thus becoming somewhat obsessed. But as time passes, I've noticed that my best vision in most normal conditions, near and far, tends to result from the two eyes working together, and not so much from one lens being superior to the other.

Mixing Multifocal Lenses: The Results

If you are considering multifocal lenses, you must be prepared for the probability of a few relatively minor side effects unrelated to mixing lenses.

For example, I do see halos and mild starbursts around light sources at night. These "light shows" are gradually diminishing. I can now drive safely at night, especially considering what I experienced with cataracts and the huge starbursts they caused from oncoming headlights. I find wearing multifocals, even with night halos associated with both lenses, an acceptable tradeoff. Overall, my night vision now is significantly better in terms of seeing contrast and details. Of course, I naturally would prefer not to see halos at all.

The ReZoom multifocal IOL is designed to deliver balanced view optics, according to the manufacturer. Diagram supplied by Abbott Medical Optics and Dr. William Fishkind.

In some indoor, low light conditions, vision is not absolutely, perfectly sharp. If you use cameras, you might understand the analogy of taking a photo in "available light" versus using flash. Available light photos can be in focus, but they don't have the crispness of a photo taken with flash. Both types of images are focused and look good, though. So this is how I sometimes see through multifocals in low lighting indoors, as though the scene were photographed in available light with a good but not crisp result.

Daytime distance vision is beyond excellent, however. I see better in the great outdoors than I ever have in my life, even in younger years. Details are intricate, from individually defined feathers on birds to the fine detailing of rock walls. I delight in being outdoors with my multifocal lenses, especially now that my bright color vision has been recaptured with the elimination of cataracts.

Near vision could be better, but it's acceptable. For example, I don't just automatically read tiny print. I need to adjust the distance first and then concentrate on reading extremely fine print. Regular reading is better, but requires adequate lighting. I would be out of luck trying to read a menu with fine print in a dark restaurant.

I may need computer glasses eventually, just for the additional clarity. But I'm giving adaptation a try before turning to any kind of "crutch" for now. I spend many hours in front of the computer, so obviously I've been able to manage with the vision I have without eyeglasses.

The main point here is that I've functioned quite well for weeks now, at all distances, without needing eyeglasses. And I do believe that mixing the two currently FDA-approved multifocal lenses, the ReZoom and ReSTOR, is a good option for qualified candidates.

Had the two lenses not been mixed, I absolutely would have needed eyeglasses for reading fine print or for computer work. With this option, however, I can function comfortably and normally with the vision I now have even if I never wear eyeglasses again.

Are You a Candidate for Mixing Multifocal Intraocular Lenses?

If you are a perfectionist, hard to please and have been satisfied with the vision (corrected or uncorrected) you have currently, you might not be a good candidate for multifocal intraocular lenses. You must be prepared for somewhat of a tradeoff, with the understanding that you are unlikely to fully recapture the kind of vision you had as a 20-year-old in exchange for potentially being able to see at all distances.

Remember that surgical outcomes vary, sometimes depending on surgeon skill and experience. Make sure you discuss with your eye surgeon all options that are available to you, as well as potential problems and complications. Be sure that you know what additional payment might be required if you require an enhancement, such as LASIK, following a multifocal lens implant.

The type of vision errors you have and your basic eye health also will determine whether you are a good candidate for mixing multifocal intraocular lenses. Keep in mind that all eye surgery has risks, some of them sight-threatening in rare cases.

Update: Two Years Later

Fluctuating, blurry vision in early 2009 prompted a follow-up visit with a local ophthalmologist who also is a cataract surgeon.

Following the eye exam, I discovered I had lost two lines of uncorrected distance vision in my right eye (20/40) with the ReZoom IOL and one-half line in my left eye (20/25) with the ReSTOR IOL. I also lost one line of uncorrected near vision in my right eye (20/30) and one line in my left eye (20/25).

These outcomes still are considered very good, but my vision clearly had declined from the excellent results recorded two years previously.

Because my vision clarity fluctuates, I thought I had a common cataract surgery complication that causes a "secondary cataract." However, both eyes were mostly clear of this type of problem. My retinas also looked healthy. My eye doctor instead suggested that fluctuations could be due to dry eye.

This makes sense, because I live in one of the driest areas of the United States. I also spend many hours in front of the computer, which certainly can contribute to dry eye.

A healthy cornea and tear film are important for sharp vision, particularly when you have multifocal IOLs. So my eye doctor suggested that I take flaxseed oil orally, and use lubricating eye drops. I noticed significant improvement within a week — and now wish I could take those eye tests over again!

However, one lingering problem that cannot be corrected so easily is the return of almost one diopter of astigmatism in my right eye. While I had limbal relaxing incisions (LRIs) to flatten the cornea and rid that eye of astigmatism, the procedure did not last. So I always will have slight blurry vision in my right (ReZoom) eye now, due to astigmatism.

I do now use over-the-counter reading glasses for working at intermediate distances on my laptop computer. But most of the time, I still do not need to wear eyeglasses at all. Again, this is considered an acceptable outcome.

I also still have night vision problems including glare and halos, but these distortions are not severe and do not impede driving ability. Also, these visual distortions declined during the past two years as I adapted to seeing through multifocal IOLs.

Would I do the same thing with the options that were available in 2007 — that is, mix multifocal IOLs? Yes, I would. I believe this was the very best option available for my particular vision correction needs at that time.

Would I do the exact same thing today? Probably not, because new FDA-approved versions of presbyopia-correcting IOLs now are available. Naturally I would consult with my eye surgeon first. But I likely again would select "modified monovision" through mixing different types of IOLs. This time, however, I would have the choice of Alcon's newest version of the ReSTOR, to enhance intermediate vision.

AMO also recently received FDA approval of the Tecnis multifocal IOL, which provides great near vision similar to the original version of ReSTOR. My impression of the ReZoom IOL now (unfortunately) is somewhat skewed by astigmatism. But I might consider combining the Tecnis with the ReZoom, based on an eye surgeon's opinion of what might work best.

If you and your eye surgeon are considering combining presbyopia-correcting IOLs, another option might be the newest version of Crystalens (Bausch & Lomb). The Crystalens is not a multifocal IOL, but instead shifts within the eye to "accommodate" or provide focus at multiple distances. A study reported in the American Journal of Ophthalmology (September 2007) demonstrated that an earlier version of the Crystalens provided good intermediate and near vision, with better contrast sensitivity and less chance of night vision problems.

In the future, look for FDA approvals of toric multifocal IOLs that also can correct astigmatism. These types of IOLs eventually might replace limbal relaxing incisions, which currently remain the best option for astigmatism correction combined with use of presbyopia-correcting IOLs.

At this time, I am happy with my vision while being somewhat disappointed in the return of astigmatism, which causes slight blurring in my right eye. Before this happened, the ReZoom eye had distinct strengths that no longer are as evident, such as sharper distance focus in certain lighting conditions.

[Page updated July 2009]