This article is more than 5 years old. Information may no longer be current.
Considering new EDOF and multifocal technologies, what is the role of accommodating IOLs?
Click Here to Manage Email Alerts
Click here to view the Cover Story to this Point/Counter.
Accommodating IOLs still a useful tool
The challenges associated with accommodating IOLs are well known and include variable efficacy, reliance upon meticulous surgical technique, inconsistent refractive predictability, susceptibility to capsular contraction, a smaller optical zone and high rates of posterior capsular opacification. Despite these obstacles, it is clear from a large body of clinical experience that accommodating IOLs offer the equivalent of about 1 D of additional near add power without the optical compromises associated with all other posterior chamber IOLs. Low add multifocals have improved dramatically and are now well tolerated by the overwhelming majority of patients. Variable add powers have increased the functional envelope of multifocals. The availability of EDOF IOLs has truly changed the game by consistently providing good distance and intermediate vision with minimal photic phenomena. EDOF IOLs have also allowed us to offer presbyopia correction to patients we might previously have excluded, such as patients with mild glaucoma, retinal issues and even corneal irregularities. The availability of toric EDOF IOLs has further expanded their use.
Still, there are still posterior chamber IOL-seeking patients who are only candidates for the monofocal optic of an accommodating IOL owing to their inability to tolerate the optical compromises associated with all other posterior chamber IOL options. And when given the choice, there are some patients who would greatly prefer occasionally using readers over a situation in which the quality of their distance vision was compromised in any way. Toric accommodating IOLs also offer an advantage in patients at higher risk for rotation postoperatively, such as those with large anterior segments. The Crystalens (Bausch + Lomb) is highly resistant to rotation, and it can be placed in large eyes without fear of rotational instability. While the use of accommodating IOLs has declined as other options have improved, they are still a useful tool in the armamentarium of a refractive cataract surgeon.
Steven J. Dell, MD, is an OSN Refractive Surgery Board Member. Disclosure: Dell reports he is a consultant to Johnson & Johnson Vision and Bausch + Lomb Surgical.
Accommodating IOLs have challenges
Multifocal and EDOF IOLs help a large number of patients, although not all patients are candidates. The technology has improved compared with previous multifocal IOLs, with superior quality of vision and decreased risk for night vision complaints. However, there are still drawbacks with multifocal and EDOF IOLs, as patients with corneal conditions or retinal conditions may not be optimal candidates, and some patients who are appropriate candidates may still experience significant night vision complaints. A truly accommodating IOL could provide high-definition and high-quality vision at all ranges and would be a game-changing technology for patients. It is an exciting concept, but to date scientists have not been able to design an accommodating IOL that consistently provides a wide range of vision. One challenge is that accommodation is a highly sophisticated dynamic process that involves many components of the optical system and is hard to replicate. That is one reason that research has struggled for many years without achieving the goal.
The Crystalens (Bausch + Lomb) is available in the U.S., and I have implanted all of the different versions in the past. I found the Crystalens could achieve some increased range of vision compared with a monofocal IOL. Patients who had the best range of vision with the Crystalens were those with the smallest pupil size during accommodation, as well as those patients with the steepest corneas. Using a dynamic high-definition wavefront aberrometer, we realized that it was not so much a shift in power of the lens, but changes in spherical aberration and other higher-order aberrations that provided the increased range of vision. It was more of a pseudoaccommodation EDOF effect rather than a shift in the power of the IOL when patients changed their focus from distance to near. The future does hold promise. Some new technologies, such as the PowerVision FluidVision lens, are undergoing evaluation, and we hope they will be successful. For the time being, in my practice I use the Symfony IOL (Johnson & Johnson Vision) and other multifocal IOLs with consistent, satisfactory outcomes in patients who are good candidates for the technology.
- Reference:
- Trattler W, et al. Open-label evaluation of degree of accommodation in pseudophakic patients bilaterally implanted with monofocal intraocular lenses. E-poster 1863. Presented at European Society of Cataract and Refractive Surgeons annual meeting; Sept. 5, 2010; Paris.
William B. Trattler, MD, is OSN Technology Section Editor. Disclosure: Trattler reports he is a consultant and speaker with Johnson & Johnson and Bausch + Lomb.