IOL Selection: What Do You Consider When Choosing a Lens?

What top cataract surgeons look for — and forward to — in a lens.

By Leslie Goldberg, Associate Editor

When it comes to selecting an IOL for a patient, many ophthalmologists agree that the most influential factors in determining their choice are patient lifestyle, meeting vision goals and biometry. The good news for both doctors and patients is that there is a wide array of high-quality lenses currently available and some breakthrough lenses soon to be available.

Lifestyle and Lens Choice

Whether your practice uses a questionnaire or you speak directly with patients to determine the IOL type and power that is right for them, patient lifestyle is a major determining factor in selecting an IOL. Doctors want to know how their patients spend their time, especially in terms of performing tasks that require excellent close, middle or distance vision.

"There is still some art to this," says John Vukich, MD, of Madison, Wisc. "There are some limitations to all of the currently available lenses. What you want to do is match patients' needs to the strengths of your choices."

Mark Packer, MD, of Eugene, Ore., provides all of his patients with three options. Option 1 is a monofocal; usually an aspheric lens and astigmatism is not corrected. Option 2 includes correcting for astigmatism with LRI or a toric IOL. The goal for this option is to be glasses-free for distance but use of glasses for reading. Option 3 includes a presbyopiacorrecting lens where the goal is to never need glasses.

"I believe everyone should know their options and I feel strongly that the surgeon should make a recommendation based on lifestyle, desires and goals for vision," says Dr. Packer.

David A. Goldman MD, assistant professor of clinical ophthalmology at Bascom Palmer Eye Institute, asks his patients directly what they'd most like to be able to do after cataract surgery. He says this gives him an opportunity to see how realistic his patients' expectations are and what compromises in vision, if any, they are willing to accept. "A person who does a lot of night driving is not a great candidate for a multifocal lens. However, an older patient who doesn't drive but does a lot of fine work at a very close focal point may do better with a multifocal IOL," notes Dr. Goldman.

Farrell (Toby) Tyson, MD, of Cape Coral, Fla., says that patients resent the added paperwork of a questionnaire, so he spends additional chair time with patients getting to know what they like to do. If reading is very important to a patient, he will recommend the Tecnis multifocal (AMO). If they use the computer a great deal, he will choose a ReStor 3.0 (Alcon) or possibly a Crystalens AO (B+L). For his postmyopic LASIK patients who desire presbyopic correction, he will go with a Tecnis multifocal because patients get induced spherical aberrations and the Tecnis reduces them.

Other Influences

William Wiley, MD, of the Cleveland Eye Clinic, says that it is important to look at a patient's preoperative prescription. "If a patient is hyperopic or a high myope, he/she will tend to do well with just about any IOL. If a patient has astigmatism, I tend to use an astigmatism correcting IOL along with the ORange [WaveTec Vision] intraoperative aberrometer to guide IOL power and position," says Dr.Wiley. Lastly, if they are low myopes, he leans towards a monofocal IOL with monovision correction. "Patients seem to not see the value in presbyopic IOLs when they are low myopes," adds Dr. Wiley.

Dr. Wiley also looks at the density of the cataract, noting that if the cataract is quite dense, patients tend to be happy with any IOL; if the cataract is mild, they may not like the compromises that multifocals may require.

Lastly, he notes the patient's age. "Younger patients tend to be more motivated to have a presbyopic IOL. It seems older patients are resigned to the fact that they will wear readers and may not be as motivated," he says.

Dr. Goldman says that the factor that influences his choice first and foremost is the patient's desire for spectacle independence. He says many of his patients "could not care less if they had to wear glasses afterwards," and some patients even feel uncomfortable if they don't have their glasses on. He recommends monofocal lenses for them.

He performs corneal topography preoperatively on cataract surgery patients and, if they have a high amount of astigmatism and want to be rid of glasses, he'll recommend monovision with toric IOLs.

"While accommodating and multifocal lenses can perform well when the astigmatism is corrected with LRIs or laser vision correction, I find the overall satisfaction with these lenses is not as good when higher degrees of astigmatism need correction," says Dr. Goldman.

"Patients with over 1.5 D of corneal astigmatism are less likely to have this completely eliminated by LRIs, so they may require a step-wise approach to presbyopia-correcting IOLs using a bioptic technique," says Jay S. Pepose, MD, director of Pepose Vision Institute. "If they are looking for a ‘quick fix,’ these patients may currently be better candidates for a toric IOL using monovision, at least until toric presbyopia-correcting IOLs become available."

"Go To" Lenses

In theory, Dr. Wiley loves the idea of an "accommodating" IOL. "In practice, it seems that the current versions of accommodating IOLs may not reach the patient's expectations of glasses independence for near vision," he says. "Thus, my go-to IOL has been the ReStor +3.0 add. It seems to deliver the near vision that patients are looking for."

In terms of expectations, he has a long discussion with his patients in regards to potential side effects prior to surgery, and if they are okay with the potential risks, he feels comfortable proceeding with the multifocal platform.

"I use all the lenses and enjoy the toric IOL because patients usually know in advance that they have astigmatism and so chair time is minimal," says Dr. Goldman. "Results with these lenses are extremely accurate, but unless the patient can tolerate monovision, they will not be satisfied with their postop vision."

For most of his patients who desire spectacle independence, he finds the Crystalens AO yields great results. "The majority of my patients are at least 20/25 and J2, which gets them out of glasses almost entirely. However, if the patient is a successful wearer of multifocal contact lenses or a very high myope I'll use the +3 aspheric ReStor lens," adds Dr. Goldman.

Dr. Pepose's "go to" lens has been the Crystalens HD. He has also had good experience with the Crystalens AO, which has enhanced aspheric optics, and in some patients, he has mixed the two lenses. "In those cases, I place the HD in the dominant eye, which seems to optimize distance and intermediate and if I need to offset the non-dominant eye for a slightly myopic target, I may favor the AO. My goal has been to optimize visual quality and not sacrifice contrast sensitivity," says Dr. Pepose.

Dr. Tyson reaches for the Tecnis multifocal first. His patients are happy with its excellent distance and reading vision and he finds it more than sufficient for intermediate distance.

He recommends the ReStor 3.0 for patients who spend a lot of time on the computer, and says he has shied away from accommodating lenses because it is harder to hit refractive outcomes the first time.

Dr. Vukich tends to use the Crystalens with a mini-monovision strategy. He also uses the ReStor 3.0 and Tecnis multifocal in select patients. He says that with multifocals, he tries to match to the lens to the patient's needs.

IOLs for Preexisting Conditions

For preexisting or coexisting conditions such as CME, glaucoma or uveitis, Dr. Goldman always chooses acrylic over silicone lenses because he is concerned the patient may need future retinal surgical intervention. "If the patient is asymptomatic with pseudoexfoliation glaucoma, I prefer the Bausch+Lomb MI60L lens because of its zero asphericity. It has a little more give if there's slight dislocation later on. If the patient already has phacodonesis, I'll use the Hoya PC-60AD IOL because I can still implant it via a 2.4-mm incision and it's a three-piece lens that I can fixate to the iris when there's not sufficient zonular support," ex plains Dr. Goldman.

Dr. Pepose says that for preexisting and coexisting conditions, he will usually implant a standard aspheric monofocal IOL. Dr. Tyson prefers a Tecnis single-focus lens. He says that it gives the best contrast, which is beneficial in contrastreducing diseases.

With any condition that potentially limits vision, Dr. Packer is cautious with using a multifocal. "A patient may have different degrees of diabetes, with or without retinopathy, or with macular edema. They may have an epiretinal membrane — and while there is no blanket rule, I make them aware of the condition. Managing with a retina specialist is a good idea in those situations," says Dr. Packer.

Designs in Development

"I am anxiously awaiting the newer versions of accommodating IOLs that may provide the near vision that the multifocal IOLs provide without introducing side effects," says Dr. Wiley. "The dual-optic design looks interesting and the piston-design IOL fashioned after the large accommodation seen in certain seabirds looks particularly interesting." Dr. Wiley states that although he is in favor of accommodating IOLs, he has respect for the difficulty of predicting the interaction of a moving lens with the capsular bag and the healing response. "With a multifocal design, there are less healing and predicting concerns and a potential for less com plexity. Femto-phaco may allow for newer IOLs through the creation of custom-designed capsulorhexis — a small rhexis design allowing for injectable ‘liquid’ IOLs," he concludes.

Dr. Tyson is looking forward to the Synchrony dual optic accommodating lens (AMO) and hopes it will be as promising as its buildup.

Dr. Packer, an investigator for the Synchrony, thinks it will be approved in the first quarter of next year. "With the Synchrony you get near vision equivalent to a multifocal and everything between near and distance is clear — you get the full range," he says. "One thing that is important to note is that it takes about three months for the lens to settle into place because there is some constriction of the capsular bag that goes on during this time."

Dr. Packer says that initially patients are nearsighted. The near vision will be excellent but distance will be blurry during that time. He says that about 20% of patients will need a laser enhancement.

Dr. Vukich has been working with the Synchrony for over three years and was one of its original US investigators. "I have been impressed with both the short-term benefits and the fact that at three years out, patients continue to show good accommodative response, excellent distance acuities and a smooth transition through the intermediate range to the near point," he says.

He concurs that with this lens patients are myopic at first. "We believe this is due to the elastic properties of the capsular bag. It simply takes a few weeks to reach a stable state," says Dr. Vukich. "We also believe that the ciliary body, which in more mature patients has been working against a hard lens, may have to begin exercising again to regain its full dynamic range. The ciliary body seems to be able to improve its function, but this takes time."

Dr. Vukich says that while the quality of vision doesn't change in terms of best-corrected acuity, the uncorrected distance and the near response improves over the first couple of months.

Dr. Goldman is most intrigued by the NuLens accommodative (from NuLens Ltd.) and is curious to see how it performs when it is available. "If it is even half as successful as the preliminary data show, not only will it be extremely popular but it may dramatically lower our thresholds for performing refractive lens exchange," he says.

There are a number of accommodating IOLs at various stages of development that are of interest, including Synchrony, FluidVision (PowerVision) and NuLens, says Dr. Pepose. He notes that the availability of toric presbyopia-correcting IOLs in the future will be a welcome addition.

In the End

Dr. Vukich no longer presents all of the choices to his patients as it "confuses everyone and the natural response to confusion is to make no decision whatsoever. I believe that patients want us to be the doctors. They want to hear ‘based on my experience, I believe this is the best match for you.’ I think that is more reassuring." OM