The IOL market offers an ever-increasing variety of choices to today's ophthalmic surgeons—asphericity, multifocality, toricity—all presented in a wide range of materials and designs. In this mini-focus feature, several ophthalmologists outline their current IOL preferences and the reasons for those preferences.
We asked our contributors to answer four questions: (1) What is your preferred monofocal IOL? (2) What is your preferred multifocal IOL? (3) What is your preferred accommodating IOL? (4) Of the IOLs in the research pipeline but not yet on the market, choose one that you consider promising for the near future. What are its potential advantages, and how will it change the way surgeons practice?
ROBERTO BELLUCCI, MD
Monofocal IOL. My preferred monofocal IOL at this time is the Akreos MI60 microincision IOL (Bausch & Lomb, Rochester, New York). There are several reasons for my choice: (1) The Akreos material is hydrophilic acrylic, a material demonstrated to be less associated with pseudophakic photic phenomena compared with hydrophobic materials, whether acrylic or silicone. (2) The design is neutral aspheric, which does not change the optical aberrations of the eye; in particular, the spherical aberration of the cornea will be almost equal to the spherical aberration of the entire eye. Additionally, the neutral aspheric design helps maintain good optical quality in the case of lens decentration or tilt. (3) This microincision lens fits through a 1.8-mm incision, which does not change the optical properties of the cornea. (4) The lens is easy to load and implant, and (5) it does not stretch the capsular bag once implanted, a quality especially important in a patient with weak zonules or limited posterior capsular tears. (6) The lens remains centered postoperatively because of rapid capsular sealing around the four loops, and it does not demonstrate any movement due to accommodative efforts; in these respects, it behaves similarly to lenses designed for larger incisions. (7) The posterior capsular opacification (PCO) rate has been acceptable during my first 2 years using the lens, with a low Nd:YAG laser capsulotomy rate. This is probably related to the 360° square posterior edge. (8) Because the haptics have no holes, IOL removal should be easy when necessary.
Multifocal IOL. My preference is for multifocal lenses that favor distance vision, such as the AcrySof Restor (Alcon Laboratories, Inc., Fort Worth, Texas) and the Acri.tec Acri.LISA (Carl Zeiss Meditec, Jena Germany).
In particular, the Acri.LISA diffractive lens divides the light in a 2:1 distance-to-near ratio, a design that has been effective in my patients, with low levels of photic phenomena and glare reported. The ability to see distant and near objects is maintained regardless of the patient's pupil diameter, allowing reading in dim light conditions. The diffractive near add works well with high contrast tasks, such as black print on white paper, but it is less than optimal with low contrast tasks, such as sewing. For those low-contrast conditions, the distance focus can be corrected with spectacles that take advantage of the brighter distance focus, a solution that is impossible with lenses with a 1:1 distance-to-near ratio.
Accommodating IOL. I have little experience with accommodating IOLs, only with the older models of the Eyeonics Crystalens (Bausch & Lomb). That experience was moderately positive, but I discontinued implantation because patients were not completely spectacle independent for near vision. However, I am interested in the Crystalens HD, which takes advantage of a change in lens shape to increase pseudoaccommodation. In my opinion, centration can be a challenge with aberration-aided accommodating IOLs, so I am looking forward to the publication of clinical results with this lens.
In the pipeline. In the near future, a variety of microincision lenses will likely enter the market. Because the incisions for these IOLs do not alter the cornea, microincision lenses are perfect platforms for special optical designs, including aberration-correcting, hyperaspheric, pseudoaccommodating, toric, multifocal, and multifocal toric. The availability of such lenses, implantable through sub–2-mm incisions, will push cataract surgery toward the boundaries of refractive lens exchange, giving new opportunities to patients and surgeons, but also posing new ethical questions.
ERIK MERTENS, MD, FEBO
Monofocal IOL. My current preference is the AcrySof IQ one-piece aspheric IOL. It provides stable and predictable postoperative refraction.
Multifocal IOL. I prefer the aspheric AcrySof IQ Restor IOL +3.0 D. The lower add power provides a more comfortable reading distance than other currently available multifocal IOLs.
Accommodating IOL. Currently, I favor the Crystalens HD. It provides the best accommodative response among all the currently available accommodating IOLs.
In the pipeline. I am looking forward to the availability of the Light Adjustable Lens (LAL; Calhoun Vision, Pasadena, California). This lens offers the potential to adjust and eliminate residual refractive error easily after surgery.
RUDY M.M.A. NUIJTS, MD, PhD
Monofocal IOL. My preferred monofocal IOL is one with a square-edge design that results in a low PCO rate.1 The biocompatibility must be excellent, with a low risk for capsular contraction formation and good long-term centration. Additionally, a one-piece design has proven to be advantageous in terms of material handling for cartridge loading and IOL insertion through incisions as small as 2.2 mm. Asphericity has been shown to be of benefit in patients with larger pupil size under mesopic light conditions. Finally, the platform of an ideal monofocal IOL should also facilitate the inclusion of toricity.2 Although multiple IOLs now fulfill these criteria, my most extensive experience has been with the Alcon AcrySof SN60WF IOL.
Multifocal IOL. My preferred multifocal IOLs are the AcrySof Restor SN6AD3, AcrySof Restor SN6AD1, and the Acri.LISA toric IOLs. The Restor IOLs have the same advantages as the monofocal AcrySof IOLs in terms of material handling, insertion technique, PCO incidence, and biocompatibility characteristics. Surgically induced astigmatism can be minimized with a 2.2-mm incision or can be increased if needed by making larger incisions to decrease existing corneal astigmatism. Long-term, 3-year performance of the Restor IOL was excellent.3
We have preliminary experience with the Acri.LISA toric IOL, which treats both astigmatism and presbyopia. This lens has shown good results and high levels of patient satisfaction in our first 10 patients.
Accommodating IOL. I have no experience with accommodating IOLs.
In the pipeline. I expect that toric IOLs, which are being introduced into the market from most companies, will be successful. Additionally, toric multifocal IOLs show promise for the near future, potentially eliminating the need for corneal laser touch-ups or additional incisional surgery that is seen with current multifocal IOL designs.
KHIUN F. TJIA, MD
Monofocal IOL. I prefer the AcrySof Natural one-piece lens, currently the aspheric IQ model. However, I would rather that the design were aspheric-neutral. I do not like IOLs that correct spherical aberration. Few patients benefit from their potential, theoretical advantages. Rather, their theoretical drawbacks are more frequently noticeable.
Multifocal IOL. My preference is the aspheric AcrySof IQ Restor IOL +3.0 D. This IOL provides good near and intermediate vision, eliminating the need for mix-and-match strategies, in my opinion. Patients should be educated preoperatively regarding the reduced contrast sensitivity inherent in multifocality and the halos that may result after surgery. Cataract patients readily accept these sequelae; some refractive lens exchange patients do as well. I am still hesitant to recommend a multifocal IOL for emmetropic or myopic presbyopes with clear lenses.
Accommodating IOL. I have no preference regarding currently available accommodating IOLs. I do not believe that they work. The new Crystalens HD has potential, but in my opinion, I believe it has a refractive bifocal component.
In the pipeline. I foresee a growing market share for multifocal-toric IOLs as well as for hybrid accommodating-multifocal IOLs, such as the Crystalens HD. I also expect that we will see optimized diffractive multifocal IOLs from a number of companies.
KEVIN L. WALTZ, OD, MD
Monofocal IOL. My preferred monofocal IOL is the aspheric silicone Tecnis Z9002 (Advanced Medical Optics, Inc., Santa Ana, California). I like this lens because it is easy to use. It unfolds reliably in the bag. For most patients, it reduces spherical aberration to near zero postoperatively.
The Tecnis is the only lens with a US Food and Drug Administration (FDA) labeling indication stating that it improves safety while driving.
The lens offers a great value-to-benefit ratio for patients. Silicone is a time-tested IOL material, and the lens is designed with an optic edge treatment that minimizes PCO. Near UCVA is also much better than one would anticipate with a monofocal IOL. A nearly indentical lens is also available in an acrylic material.
The lens requires a 2.6-mm incision for implantation. One relative negative of the lens is that it is challenging to learn to use the inserter; complex motions are required to implant the IOL. Also, the edge design is thicker than some other IOL models.
Multifocal IOL. My preferred multifocal IOL is the Tecnis Multifocal (Advanced Medical Optics, Inc.). Among its positives: The lens provides patients with reliably great distance and near visual acuity and suprisingly good intermediate acuity. Near acuity is virtually pupil-independent, so patients can read with larger pupils in relatively dim light. The lens minimizes postoperative spherical aberration in most patients. It is designed with the familiar Tecnis platform and silicone material. It offers better chromatic aberration performance than most IOLs.
Like the Tecnis monofocal, this lens requires a 2.6-mm incision for implantation. Also like the monofocal lens, its inserter is challenging, requiring complex motions to implant the IOL. The full diffractive multifocal optic may cause more unwanted visual symptoms than a partial diffractive optic. These multifocal symptoms are usually greater than visual symptoms with an accommodating IOL.
Accommodating IOL. My preferred accommodating IOL is the Crystalens HD (Bausch & Lomb, Rochester, New York). This lens provides great distance and intermediate vision with minimal adverse optical symptoms. It is straightforward to implant with its reliable injector system.
With experience has come an improved understanding of this IOL's pseudoaccommodative mechanism of action: It undergoes accommodative arching rather than linear displacement. Elevation of the optic's central curvature provides better contrast sensitivity and intermediate and near vision with less accommodative effort on the part of the patient.
One relative negative is that this IOL sometimes provides unpredictable near vision. Also, the plate-haptic design can implant asymmetrically if the surgeon is not careful.
In the pipeline. Currently, the most promising lens in pipeline is the LAL. When this lens reaches the market, we will be able to adjust patients' sphere and cylinder postoperatively with a minimally invasive process. This should be a great option for patients who have previously undergone laser vision correction with residual higher-order aberrations (HOAs), such as high positive spherical aberration, or for patients with prior radial keratotomy. We should also be able to correct HOAs postoperatively with the same minimally invasive process.
This lens, however, will require an entirely new business model. One of our challenges will be to identify this business model and adopt it on a large scale. We will need to implant this expensive IOL in patients who may not derive much additional benefit, relative to the cost, if our initial IOL calculations are correct. For this reason, it is possible this lens may have limited market potential.
Roberto Bellucci, MD, is Director of the Ophthalmic Unit Hospital at the University of Verona, Italy. He states that he has received travel reimbursement from Alcon Laboratories, Inc., Advanced Medical Optics, Inc., and Bausch & Lomb. Dr. Bellucci may be reached at tel: +39 045 812 3035; e-mail: email@example.com or firstname.lastname@example.org.
Erik L. Mertens, MD, FEBO, is a cataract and refractive surgery specialist. Dr. Mertens is Medical Director of the Antwerp Eye Center, Antwerp, Belgium. Dr. Mertens states that he is a consultant to Bausch & Lomb and STAAR Surgical; however, he has no financial interest in any product or company mentioned. Dr. Mertens is a member of the CRST Europe Editorial Board. He may be reached at tel: +32 3 828 29 49; e-mail: email@example.com.
Rudy M.M.A. Nuijts, MD, PhD, is a an Associate Professor of Ophthalmology at the Department of Ophthalmology at Academic Hospital Maastricht, in the Netherlands. He states that he has no financial interest in the products or companies mentioned. He is a member of the CRST Europe Editorial Board. Dr. Nuijts may be reached at e-mail: firstname.lastname@example.org.
Khiun F. Tjia, MD, is an Anterior Segment Specialist at the Isala Clinics, Zwolle, Netherlands. Dr. Tjia is the Co-Chief Medical Editor of CRST Europe. He states that he is a consultant to Alcon Laboratories, Inc. Dr. Tjia may be reached at e-mail: email@example.com.
Kevin L. Waltz, OD, MD, is in private practice with Eye Surgeons of Indiana in Indianapolis. Dr. Waltz states that he is a paid consultant to Advanced Medical Optics, Inc., and Eyeonics, Inc. Dr. Waltz may be reached at tel: +1 317 845 9488; e-mail: firstname.lastname@example.org.
- Abhilakh Missier KA, Nuijts RM, Tjia KF. Posterior capsule opacification: silicone plate-haptic versus AcrySof intraocular lenses. J Cataract Refract Surg. 2003;29(8):1569-1574.
- Bauer NJ, de Vries NE, Webers CA, Hendrikse F, Nuijts RM. Astigmatism management in cataract surgery with the AcrySof toric intraocular lens. J Cataract Refract Surg. 2008;34(9):1483-1488.
- de Vries NE, Webers CA, Montés-Micó R, et al. Long-term follow-up of a multifocal apodized diffractive intraocular lens after cataract surgery. J Cataract Refract Surg. 2008;34(9):1476-1482.