IOL Technology: A Decade of Progress
Major advances have been made — and more are on the way.
By Jerry Helzner, Senior Editor
The numerous advances in ophthalmic treatments and technology over the past 10 years have led some to term the decade "a golden age" for ophthalmology. If, indeed, this is a golden age, significant progress has been made in almost every area of practice.
From drugs that reverse vision loss in wet AMD, to the rapid adoption of partial-thickness corneal transplants, to the routine use of OCT for diagnosis and disease monitoring, the pace of innovation has been stunning. However, in terms of overall impact, probably no aspect of ophthalmology has moved forward at the rate of IOL technology.
Just look back 10 years to confirm how far IOL technology has come. In the year 2000, the pioneering Array was the only approved multifocal lens, while better multifocals, accommodative and phakic lenses were still in the investigational stage. Some lens designs, such as early one-piece versions, were prone to lead to complications and some IOL materials left much to be desired in terms of biocompatibility. Toric IOL technology was in its infancy, and the first aspheric lens was not approved until 2004. Injectors were still a work in progress in 2000. Today, they are used routinely in the vast majority of cataract surgeries. They have helped advance small-incision surgery and greatly improved surgical efficiency and safety.
Contrast what was available to cataract surgeons a decade ago to the current environment, in which surgeons now have a wide range of easily inserted IOLs whose power they can more precisely calculate to meet the visual and lifestyle needs of almost any patient.
Ophthalmology Management wanted to know how top cataract surgeons view the advances in IOL technology over the past decade. We also wanted to explore their IOL "wish list" for the next 10 years. Read on and learn which advances these highly respected surgeons consider the most important. Some of their opinions may surprise you.
Surgeons Hail Progress in IOLs
From a "big picture" standpoint, David Chang, MD, of Los Altos, Calif., shares the views of many of the cataract surgeons who responded to our survey.
"The most important advance in IOL technology during the past decade has been the major improvements in refractive IOLs — specifically the latest toric, multifocal and accommodating IOL technology," asserts Dr. Chang. "In particular, the toric and diffractive multifocal IOL technologies are relatively mature designs on popular aspheric hydrophobic acrylic platforms."
Elizabeth A. Davis, MD, who practices in Minneapolis, notes the improvements in range of vision, quality of vision and reduction of side effects provided by the new generation of presbyopia-correcting IOLs. She says these lenses have been key in enhancing the quality of life for cataract surgery patients.
In Praise of Premium and Toric IOLs
In a more specific vein, a number of respondents had special praise for the latest generation of toric lenses, particularly the Alcon AcrySof IQ Toric.
"I have found the AcrySof Toric to be an amazingly accurate way to address a patient's astigmatism if the astigmatism is located in the cornea and you do all of the measurements and surgery using the proper techniques," says Michael Korenfeld, of Washington, Mo.
From Brad Black, MD, of Jeffersonville, Ind.: "In a nutshell, I believe the AcrySof Toric IOL from Alcon is the most significant advance. I say this because nearly 30% of patients obtain significantly better uncorrected visual acuity and much greater spectacle independence with the AcrySof Toric IOL." He says that the aspheric platform incorporated into this toric IOL has "greatly improved" both uncorrected and corrected visual acuities with less distortion, less glare, better contrast and providing higher resolution at nearly all levels of light.
"Toric lenses have greater accuracy than limbal relaxing incisions in reducing astigmatism and are far less dependent on variations in wound healing," adds Jay Pepose, MD, PhD, of St. Louis.
Dr. Pepose also likes the progress that has been made thus far in accommodative IOLs.
"Accommodating IOLs, as well as multifocal IOLs, have gone through a number of iterative improvements, such as aspheric modifications, that have improved image quality, depth of field and also allowed the IOL to become thinner, more malleable to accommodative effort and injectable through smaller incisions," he notes.
Dr. Devgan says much of the progress in IOL technology over the past decade is due to "commitment from the ophthalmic companies to advance the evolution of IOLs."
He cites specific examples, such as the improvement demonstrated by Abbott Medical Optics in evolving its multifocal product from the Array to the ReZoom to the Tecnis. He also notes the progress made by Alcon in developing the Aspheric ReStor +3D as an improvement over the ReStor +4D and the advance by Bausch + Lomb in creating the Crystalens AO Aspheric as its follow-up to the Crystalens AT-50.
David Hardten, MD, of Minneapolis, also lauds the move to aspheric technology.
"I think the biggest thing in the last 10 years has been the increased availability of aspheric IOLs with an increase in contrast sensitivity," he says. "The increased knowledge of capsular overlap with the resultant reduction in PCO has been a huge advance in the results as well. This also has increased the ability of IOL power prediction."
Interestingly, none of the surgeons who responded to this survey mentioned phakic IOLs as a major advance. But in the last 10 years, Staar's Visian and AMO's Verisyse have been approved and are a primary choice for high myopes, while Alcon's AcrySof CacheT is completing clinical trials.
The Tools of IOL Technology
While respondents primarily focused on the advances in IOLs, some also pointed to the tools introduced in recent years that create safer, easier and more precise surgeries that lead to better outcomes.
Richard Lindstrom, MD, of Minneapolis, cites the great value of WaveTec Vision's recently introduced ORange device in allowing surgeons to perform precise intraoperative refractions that eliminate residual refractive error.
"Along with the multifocals, accommodating and toric IOLs, the WaveTec ORange is allowing reduced dependence on glasses and enhanced quality of life," he says.
Surgeons say the pre-loaded Hoya iSert inserter is making cataract surgery easier..
"Having a variety of premium lenses to choose from to meet an individual patient's needs is a great step forward from what was available just a few years ago," says Steven Safran, MD, of Lawrenceville, NJ. "But in my mind the greatest advance in technology that has improved outcomes in premium IOL surgery is not an individual lens technology but rather the availability of the IOLMaster and SD-OCT to help choose the right lens for every potential patient. Without these devices, I don't think I�d be comfortable offering presbyopia-correcting lenses at all."
Among the premium implant technologies, Dr. Safran says that toric IOLs and Crystalens are the advances he is "most grateful to have available and the implants I utilize the most in my practice."
Dr. Devgan cites "the virtual disappearance of foldable IOLs as we have moved to injectable IOLs." Using forceps to implant an IOL in a routine cataract case is very rare, he says. "The injector offers the benefit of a closed system with less chance of user error."
In this same regard, he notes the move towards preloaded IOL injector systems as another noteworthy advancement. "Hoya's iSert is a self-contained, pre-loaded IOL system," says Dr. Devgan. "There is never a need to touch the IOL optic or load it manually. It is done right, every time. In the near future, many of our favorite IOLs will be upgraded to pre-loaded injectors."
Lens Design and Materials
Steven Silverstein, MD, of Kansas City, sees improvement in lens design and the use of more biocompatible materials but believes more has to be done in these areas.
"Much work has been done in reducing PCO in terms of edge design, edge finishing and lens material," he says. "Yet this problem has been only modestly improved upon and my suspicion is that the final answer will lie not in the IOL that is employed but a yet-to-be-determined compound which scavenges for and binds to the lens epithelial cells which cause PCO."
Phoenix-based cataract surgeon Robert Rivera, MD, views better lens materials and surgical tools as being largely responsible for the improved IOLs that lead to greater patient satisfaction.
Surgeons are now seeking greater solutions to enhance patient lifestyles than simple corrective eyewear following cataract surgery, he says. "The leap from aphakia to accepting pseudophakia as the standard of care was huge, and the leap from pseudophakia to presbyopic IOLs is proving in many ways to be just as large a leap."
Surgeons Look Ahead
The cataract surgeons surveyed for this article have specific ideas concerning the advances in IOL technology that they would like to see in the next decade.
CZM's Acri-Lisa multifocal toric IOL is already approved in Europe.
"Toric IOLs overnight have yielded an opportunity to safely and predictably reduce or eliminate significant astigmatism, providing a notably improved refractive outcome and superior optical system," says Dr. Silverstein. "The addition of a toric surface to multifocal and pseudo-accommodating platforms will be a tremendous step forward in providing the optimal unaided and aberration-free visual outcome which patients and physicians are seeking."
Some respondents also proposed IOL innovations that leapfrog any of the technologies available today.
Dr. Chang looks forward to both incremental and revolutionary progress. "In the coming decade, we anxiously await a toric multifocal IOL and next-generation accommodating IOLs. The sleeper technology could turn out to be a light-adjustable lens giving us the ability to postoperatively correct sphere and cylinder, customize asphericity and provide a blended reading add (custom-sized and centered on the pupil) — all in a standard three-piece IOL design."
Dr. Safran also sees a combination of evolutionary and revolutionary change in IOL technology. "I think most cataract surgeons would consider an accommodative IOL with 3+ diopters range of accommodative function and a consistent effective lens position with predictable refractive outcomes to be the "holy grail" of cataract surgery, provided it does not require a Houdini to place it in the eye," he says.
But then he continues: "Another nice advance would be diffractive multifocal templates that could be placed on the surface of current IOLs as a secondary procedure for patients who have already had cataract surgery with monofocal implants but would like an upgrade. Ideally, these would be reversible and have the ability to correct refractive error/astigmatism as well as provide a multifocal diffractive interface. This would give us a lot of flexibility in dealing with many patients already out there who want something done to upgrade their range of function that is not unreasonably risky or technically demanding."
According to Dr. Lindstrom, "the greatest advance in the next decade will be the incorporation of femtosecond laser-assisted cataract surgery into routine practice."
Dr. Devgan describes what he calls his "dream" lens. "What's my dream IOL? The one that most closely mimics the natural human crystalline lens that I had in my eyes when I was 22 years old," he says. Such an IOL would provide a large degree of accommodative amplitude, excellent optics, ability to neutralize any corneal aberrations (from astigmatism to spherical aberration) and long-term stability and performance, he says.
"Our IOLs have evolved considerably over the past decade, but we still have a way to go," says Dr. Devgan. "Hopefully, when it's time for my cataract surgery in the future, we'll have IOLs that are nearly identical to young human lenses. And I'll happily pay out pocket for a lifetime of excellent vision."
And Dr. Rivera gets the last word about the future by introducing an allusion to futuristic author Jules Verne into the discussion. "The technology behind diffractive and pseudo-accommodating IOLs has shown us the future of refractive cataract surgery, but the perfect lens still eludes us," he notes.
AMO's Synchrony is a muchanticipated next-generation accommodative IOL.
"Without sounding too much like Jules Verne, the perfect IOL would be a truly accommodating lens that is driven by ciliary muscle contraction, that can be used in all patients regardless of the health of their macula, that would not cause glare or halos, that would have seamless functional vision at all distances, and that would correct all degrees of spherical and cylindrical refractive error without creating any compromises in the patient's vision. Wouldn't it be amazing to have this lens?" OM
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