I would like to wish everyone a happy and prosperous 2008! In this first issue of the new year, the cover focus is our Annual IOL Issue, featuring current IOL options for 2008. A panel of renowned experts from Europe and the United States discuss the use of various refractive and diffractive multifocal IOLs, the new accommodative Crystalens Five-O (Eyeonics, Inc., Aliso Viejo, California), and mixing and matching. CRST US Chief Medical Editor David F. Chang, MD, of Los Altos, California, moderated this roundtable discussion.
I would like to highlight a few topics from this very interesting discussion. All panel members—and most likely all cataract and refractive surgeons worldwide—agree that the use of presbyopia-correcting IOLs requires more time and vigilance of the surgeon than in the era of standard cataract surgery with monofocal IOLs. Before starting presbyopia-correcting surgery, thorough knowledge of the mechanical and optical properties of these new IOLs is mandatory. Unfortunately, we still understand very little about the psychophysiology related to pseudoaccommodation and neural adaptation involved with the use of these IOLs. We also agree that more clinical data and evidence is still needed for all presbyopia-correcting IOL strategies.
One topic in the panel discussion is the lack of confidence in the presumed working mechanism of the accommodative Crystalens Five-O concept. I am also skeptical about the currently available accommodating IOLs and have not started to use them in my practice.
The newer accommodative concepts such as the dual optic Synchrony (Visiogen, Inc., Irvine, California) and the newest deformable optic concept of NuLens (NuLens, Ltd., Herzliya Pituah, Israel), as described in a feature article by Joshua Ben-Nun, MD, of Israel, and Jorge L. Alió, MD, PhD, of Alicante, Spain, are attracting a lot of attention. These concepts will probably lead to more innovations and better prototypes in the future, but I doubt that a widely accepted accommodating lens will see daylight within 10 years.
It seems that everybody also agrees that an aspheric optic design is superior for multifocal IOLs. Nevertheless, we will have to wait for the clinical evidence to prove this.
We all understand and accept that current presbyopia-correcting (or presbyopia-correction–attempting) IOLs have limitations and drawbacks. One drawback of diffractive multifocal—in fact bifocal—IOLs is mediocre intermediate vision in most patients. The future launch of lower-add diffractive IOLs, which theoretically could perform significantly better in mid-range distances, is on the way in 2008. I am curious whether this could improve the overall visual performance of my patients. If intermediate vision would be satisfactory without any significant compromise to near vision and/or unacceptable side effects, such a lower-add multifocal IOL could alleviate the need for complex mixing and matching strategies. Time will tell!
In a cataract surgery feature article, Rupert Menapace, MD, of Vienna, Austria, describes his ultimate technique to prevent any form of posterior capsular opacification by posterior capsulorrhexis and optic buttoning. I have seen other respected colleagues promoting this strategy, and I admire their daringness. But, I doubt whether this will become a standard practice. I must admit that I am also hesitant about the idea of performing a posterior continuous curvilinear capsulorrhexis routinely.
In another feature story, Josef Wolff, MD, of Düsseldorf, Germany, describes the Acri.Tec Acri.LISA (Carl Zeiss Meditec, AG, Jena, Germany), a toric diffractive multifocal IOL. Combining toric and multifocal technology is certainly the most desired evolution for our refractive cataract practices. The predictability of refractive outcomes with toric multifocal IOLs should be more accurate than limbal relaxing incisions, provided that lens centration and rotational stability is excellent.
Induced astigmatism is another hot topic, which leads to our mini focus on microincision cataract surgery. All major companies have developed new platforms for smaller-incision lens surgery. In this series of mini focus articles, authors describe their technique with the Signature (Advanced Medical Optics, Inc., Santa Ana, California), Stellaris (Bausch & Lomb, Rochester, New York), Infiniti/OZil (Alcon Laboratories, Inc., Fort Worth, Texas), and Oertli CO-MICS (Oertli Instrumente AG, Berneck, Switzerland) systems. All offer a 2.2-mm or smaller incision technology that does not induce any significant astigmatism.
There is still ongoing discussion about the bare needle bimanual approach and the coaxial microphaco technique. The latter has seemed to acquire much wider acceptance lately. The introduction of novel IOL and injector systems is the key factor in the fast upcoming success of microincision cataract surgery.
The development of safer microincision phaco surgery with lower induced astigmatism and the evolution of presbyopia-correcting or toric IOLs has led us to a crossroad where we can offer more efficient, safer, and predictable visual outcomes for our patients in the future. I am sure that 2008 will be an exciting year for us!
