Experts praise advances in toric IOL technology, advocate wider adoption
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Advances in toric IOL technology and the option to correct presbyopia and astigmatism with the same lens have significantly widened the pool of potential advanced-technology IOL users, offering the benefits of spectacle-free vision.
Enhanced rotational stability, with the latest improvements in haptic design, and faster unfolding properties have reduced risks and limitations of previous toric platforms. In addition, a wider range in terms of magnitude of astigmatism, on both the upper and lower end, is now available for toric IOLs. But the most important step forward has been the merging of astigmatism correction with presbyopia correction in IOLs, according to Healio/OSN Board Member George O. Waring IV, MD, FACS.
Source: George O. Waring IV, MD, FACS
“That was a huge game changer, by far and away the largest improvement. The wonderful thing about this is that we have never had more options for a wide range and more customized approach to presbyopia correction and astigmatism correction,” he said.
Astigmatism is largely prevalent in all ages and significantly affects vision if uncorrected.
“If you don’t treat it, patients are not going to be happy. Even just half a diopter of residual astigmatism may impact on the final outcomes. Incisional techniques are an option, but freehanded limbal relaxing incisions are unpredictable, and you should at least rely on femto astigmatic keratotomy. However, toric IOLs are far better and are now a low hanging fruit we should all pick,” P. Dee G. Stephenson, MD, FACS, said.
Monofocal toric IOLs
Among monofocal toric options, the AcrySof IQ toric (Alcon) was the first to enter the U.S. market in 2009 and is currently the most implanted toric by U.S. surgeons.
“It has a sweet spot of unfolding time, but this is compensated by excellent capsular adhesion and favorable rotational stability,” Waring said.
The enVista toric (Bausch + Lomb), approved for sale in the U.S. in 2020, is a one-piece IOL that “shines in that it’s the fastest unfolding of any of the acrylic toric implants, leading to enhanced rotational stability,” according to Waring.
A unique advantage of enVista is that it allows correction of a low amount of astigmatism, below 1 D.
“It is the first of its kind in this respect, and it has widened the access to toric IOL technology for the many patients with low astigmatism who could not reduce their dependence on distance spectacles following cataract surgery,” Stephenson said.
In a study, Stephenson compared two groups of patients with low astigmatism implanted with either the toric enVista MX60PT (preloaded toric) or the non-toric enVista MX60PL (preloaded monofocal). Uncorrected vision was significantly better in the toric group.
“UCVA of 20/20 or better was achieved in 94% of the toric patients vs. 73% of the non-toric. At 3 months, 100% had achieved 20/20 or better BCVA, and 3% were 20/15, while in the non-toric group, 88% were 20/20, and none were better,” she said.
The Tecnis toric II (Johnson & Johnson Vision) is the most recent acquisition in the monofocal toric scenario. It has a newly engineered haptic profile with a square edge and a frictional element that provides “unprecedented” rotational stability, according to Waring, who implanted the first commercially available Tecnis toric II in the world.
Combining astigmatism and presbyopia correction
Presbyopia-correcting IOLs can now rely on improvements that have reduced photic phenomena and neuroadaptation problems. This makes them better suited as a platform for astigmatic correction than in the past.
“With the new multifocal and EDOF IOLs, we are seeing better intermediate and near vision without tradeoffs. I feel really lucky to be practicing in a time when we have so many options that until about 2 years ago were not available. I can offer advanced-technology IOLs to so many more patients now because I don’t have to worry about suboptimal outcomes and side effects, whereas before I had to be so selective,” Seth M. Pantanelli, MD, said.
“These days, the vast majority of my torics are presbyopia-reducing IOLs,” Alpa S. Patel, MD, said. “It’s two birds with one stone, a life-changing opportunity.”
The PanOptix toric (Alcon), the leading presbyopic option that can also treat astigmatism, is a diffractive trifocal lens that gives excellent distance, intermediate and reading vision.
“It gives you 20/20 at all three distances, a full range of vision. A minority of patients may report some glare and halos, but most find it to be visually insignificant over time, once they neuroadapt after bilateral implantation,” Patel said.
However, trifocal technology, such as the PanOptix, requires precise refractive targeting, Waring said.
“Being so optically complex, with a third single focus point, trifocals as a class are very sensitive to residual refractive error. So, you need to nail your refractive targets, and your enhancement rates may increase,” he said.
The Tecnis Symfony toric (Johnson & Johnson Vision) and the AcrySof Vivity toric (Alcon) fall into the category of extended depth of focus (EDOF).
“It is important to have EDOF in a toric platform. Pure EDOF lenses provide continuous range of vision in a more natural way but tend to fall short on the near requirements. On the other hand, they are more forgiving with residual refractive error, not only in terms of defocus, but also in terms of astigmatism, and are therefore less likely to require postoperative enhancement. However, residual astigmatism can reduce the available depth of focus,” Waring said.
Vivity is Pantanelli’s favorite new lens, the one he would implant in his own eyes.
“It almost has it all. It is a toric presbyopia-correcting lens, it has a very favorable glare and halos profile and outstanding visual quality, and it gives you functional intermediate and even some near. It is really an incredible lens,” he said.
He also likes it because it is well tolerated by less-than-perfect eyes that would have problems with other lenses.
“While with the PanOptix you must look for eyes that have no issues, Vivity is much more forgiving and can be implanted even in patients with a touch of macular degeneration and BCVA around 20/25 or 20/40. You can also implant it in post-LASIK patients. My multifocal volume has doubled in the last year or so thanks to this lens,” he said.
“I have used it for patients with controlled glaucoma or macular disease, early epiretinal membrane, for example, or some drusen, and you’ll still be able to offer them an opportunity for improved visual function compared to a monofocal IOL,” Patel said. “And if you have patients who have healthy eyes but are very concerned about glare and halos, those would also be good Vivity candidates because the IOL is nondiffractive and it doesn’t split light.”
Mixed technologies
The most recent entry into the market is the Tecnis Synergy toric II (Johnson & Johnson Vision), which is a combination of both technologies.
“It is the first available hybrid multifocal extended depth of focus lens, which almost creates a new category. In addition, it has the increased rotational stability of the Tecnis toric II, with the squared edge and frictional element,” Waring said. “Furthermore, this IOL has a violet filter, which makes it quite unique in that it is the only presbyopia-correcting lens that has improved contrast in mesopic conditions. Because of that, we have high performance reading in low light. Finally, it provides the broadest range of vision to date with a very near addition, almost like a fourth reading point. This makes it sensitive to refractive error, and like the PanOptix, it requires perfectly healthy eyes for success.”
Within the Tecnis platform, the Eyhance toric monofocal (Johnson & Johnson Vision) was designed to provide a slight increase in the depth of focus compared with a standard monofocal, potentially leading to some degree of spectacle independence.
“I found that patients do gain a little more intermediate vision as compared with the monofocal toric, and it may be a very good choice for patients with contraindications for multifocals who still want some spectacle independence. I had a patient with a history of herpes simplex virus and corneal scar who really wanted to be spectacle-free. She had some astigmatism. I felt uncomfortable implanting a PanOptix and even a Vivity, but I said OK, the best I can do is an Eyhance, and she did great. She cannot see everything at close, but she is better than she could be with a standard monofocal,” Pantanelli said.
Slow rate of adoption
Despite the advantages they offer, toric IOLs are still used by a minority of surgeons, and the rate of adoption is slow.
“It’s a mindset. When ophthalmologists have been in practice for 10 or 15 years and are not used to correcting astigmatism, it takes a lot for them to step off. They don’t know how to explain astigmatism to their patients, they are reluctant to buy new equipment, and they are afraid of making mistakes. Younger ophthalmologists, those who are coming out of residency today, are learning more about astigmatism and are keener on using advanced technologies,” Stephenson said.
“We must start with our residency programs, with our younger doctors, introducing them to the technology. Astigmatism management requires a very specific set of skills, from preoperative planning to implantation and intraoperative alignment and postoperative enhancements,” Patel said.
Physicians can educate patients about the advantages of toric IOLs. By simply using a phoropter, patients can be guided to see the difference between having and not having their astigmatism corrected.
“They must be told that this clarity of vision can be achieved with a pair of glasses or with the lens we are going to implant. Ultimately, it’s their choice, but we need to inform them because they are likely to have friends who are spectacle-free after cataract surgery, and understandably, they expect the same,” Stephenson said.
The proper tools
Some physicians might be intimidated by the number of tools and technologies that have become available to optimize toric IOL implantation and may be discouraged by the investment they require. However, not much is needed to start off with these lenses.
“You should have a topographer, which most offices already have, and a modern biometer. And give your patients a little more chair time to explain the technology,” Patel said.
“A topographer and a good updated biometer — those are the two things that you need. The rest is bells and whistles,” Stephenson said. “As an established premium surgeon, I do have every bell and whistle, but I didn’t buy them all at the same time.”
“I always recommend measuring with two different devices at least, and it is also a good idea to note the patient’s manifest refraction,” Pantanelli said.
He believes that nowadays everyone should be using a modern toric calculator, such as Barrett or Kane, which takes into account, at least empirically, the effect of the posterior cornea.
“Calculators that incorporate measurement of the posterior cornea rather than just empirically accounting for it are now the gold standard,” he said.
Surgery
The implantation itself is the same as for a monofocal IOL, but marking the axis properly and taking cyclotorsion into account are mandatory.
“We have now real-time intraoperative alignment devices with the Zeiss Callisto, and coupling of this with preoperative diagnostics, whether this is for capsulotomy marking, corneal marking or real-time overlay, is a very powerful combination that represents the future of alignment,” Waring said.
To help decrease postoperative rotation, he recommended completely removing the ophthalmic viscosurgical device (OVD) from behind the lens and applying a slight anterior pressure to the optic at the end of the case to see if the implant is properly aligned in the correct astigmatic axis.
“Be patient, and ensure that the haptics have fully deployed prior to the end of surgery,” he said.
Stephenson uses a capsular tension ring. Although evidence from large comparative studies is lacking, anecdotal reports suggest that this might help to reduce rotation after implantation, particularly in long eyes, she said.
“For alignment, I have the Cassini that gives me the axis and magnitude, and I confirm that with the ORA (Alcon). The IntelliAxis system of the Lensar has the ability to make small tabs on the anterior capsular rim during capsulotomy. So, if the lens rotates, I can see it the first postop day because the toric marks on the lens are not lined up with the IntelliAxis marks on the capsule,” she said.
At the end of surgery, she has the patients lie flat in the recovery room for about 10 minutes and recommends they take it easy for that day because rotation mostly happens in the first 24 hours.
“Then I do what I call a ‘toric check’ the following week using the iTrace (Tracey Technologies), which tells me where the lens is sitting and if there is any residual astigmatism,” she said.
Rotation
Postoperative rotation occurs less frequently with the new toric lenses, but it is still a scary adverse event that causes unpredictable visual outcomes.
The Berdahl & Hardten Toric Results Analyzer, found at astigmatismfix.com, is specifically designed to check if a toric IOL is still aligned or has rotated after surgery. If rotation is detected, it helps to determine the ideal amount of re-rotation and the expected residual error.
“You plug in what you were looking for, you plug in what you got, and the calculator tells you where to go,” Stephenson said.
Postoperative refraction must be performed routinely to check if rotation has occurred, Pantanelli said.
“All of my patients get a 1-week postop refraction. It might not be so accurate that I can use it to prescribe glasses, but it is going to be accurate enough that I can find a problem if it is there. If we find inconsistencies, we bring the patient back 2 weeks later to do another refraction and a dilated exam,” he said.
His algorithm is, first, go back to the original biometry and recheck the quality of it. Then, check the intended axis alignment and make sure it lines up with the actual axis alignment on a dilated exam. Finally, use astigmatismfix.com.
“Plug in all your values, and it will tell you if the toric IOL is in an ideal position or needs to be re-rotated,” he said.
Waring recommended fixing rotation problems as soon as they are identified, and if it is indicated, before capsular fibrosis.
After planning the repositioning with a combination of diagnostic tools such as the iTrace and the Berdahl & Hardten calculator, the intended axis and the current axis are marked based on how many degrees of rotation are needed.
“Typically, you would just access with an OVD. A dispersive more easily finds its way behind the lens and also provides better protection of the corneal endothelium. But a cohesive is easier to remove completely and efficiently. You may consider a combination if needed. You inflate the capsule and ensure that the haptics are freely mobile and that there is no fibrosis, and then rotate the IOL to your intended axis, aspirate the OVD completely and finish in the usual fashion,” Waring said.
Quality of life improvement and cost savings
“I do advanced-technology cataract surgery in more than 60% of my patients because I live in an area where seniors are very active. I have 80-year-olds on motorcycles and a 91-year-old who minds the gate at his living community and often does the midnight to 6 a.m. shift. I have a lot of golfers, pickleball players, people who do woodwork or needlecraft. When properly informed, most of them choose these lenses,” Patel said.
Both the passive- and active-use values related to these toric lenses are significant, according to Waring.
“They offer the opportunity to significantly improve quality of life, which is a passive-use value, but there is also the true value of what you will save these patients over a lifetime in glasses, bifocals and/or contact lenses,” he said.
The health care cost-saving effects related to fall prevention also deserve consideration.
“Falls kill more Americans every year than breast cancer or prostate cancer, and one-third of these falls are due to the use of bifocal glasses, which are what the majority of patients will be wearing if we don’t address astigmatism at the time of cataract surgery. So, there’s a real public health opportunity, which has a direct effect on the economy and on the waste of resources that go into dealing with this burden of falls. We really must think about these figures and take a more active approach in educating our colleagues and patients,” Waring said.
- References:
- Alcon announces launch of AcrySof IQ Vivity, the first and only non-diffractive extended depth of focus intraocular lens in the U.S. https://www.alcon.com/media-release/alcon-announces-launch-acrysof-iq-vivity-first-and-only-non-diffractive-extended. Published Jan. 7, 2021.
- Alcon introduces AcrySof IQ PanOptix trifocal IOL in the U.S., the first and only FDA-approved trifocal lens. https://www.alcon.com/media-release/alcon-introduces-acrysof-iq-panoptix-trifocal-iol-us-first-and-only-fda-approved. Published Aug. 27, 2019.
- Bausch + Lomb introduces enVista toric MX60ET intraocular lens with StableFlex technology. https://ir.bauschhealth.com/news-releases/2019/12-11-2019-132947349. Published Dec. 11, 2019.
- Gupta PC, et al. Curr Opin Ophthalmol. 2018;doi:10.1097/ICU.0000000000000446.
- Johnson & Johnson Vision announces the approval of Tecnis Synergy and Tecnis Synergy toric II IOLs in the U.S. and Tecnis Synergy toric II IOLs in Canada. https://www.jjvision.com/press-release/johnson-johnson-vision-announces-approval-tecnis-synergytm-and-tecnis-synergytm-toric. Published May 6, 2021.
- Johnson & Johnson Vision introduces Tecnis toric II 1-piece IOL as new monofocal option for cataract patients with astigmatism; launching multi-center, post-market clinical trials across U.S. https://www.jjvision.com/press-release/johnson-johnson-vision-introduces-tecnis-toric-ii-1-piece-iol-new-monofocal-option. Published Dec. 3, 2019.
- Johnson & Johnson Vision receives FDA approval for next generation monofocal intraocular lens - Tecnis Eyhance and Tecnis Eyhance toric II IOLs - for the treatment of cataract patients. https://www.jjvision.com/press-release/johnson-johnson-vision-receives-fda-approval-next-generation-monofocal-intraocular. Published Feb. 2, 2021.
- Lake JC, et al. Cochrane Database Syst Rev. 2019;doi:10.1002/14651858.CD012801.pub2.
- Sigireddi RR, et al. Curr Opin Ophthalmol. 2020;doi:10.1097/ICU.0000000000000627.
- For more information:
- Seth M. Pantanelli, MD, can be reached at Penn State Health Eye Center, 200 Campus Drive, Hershey, PA 17033; email: spantanelli@pennstatehealth.psu.edu.
- Alpa S. Patel, MD, can be reached at South Coast Eye Care Centers, 24022 Calle De La Plata, Suite 305, Laguna Hills, CA 92653; email: aspmax2003@yahoo.com.
- P. Dee G. Stephenson, MD, FACS, can be reached at Stephenson Eye Associates, 200 Palermo Place, Venice, FL 34285; email: eyedrdee@aol.com.
- George O. Waring IV, MD, FACS, can be reached at Waring Vision Institute, 735 Johnnie Dodds Blvd., Suite 101, Mt. Pleasant, SC 29464; email: gwaring@waringvision.com.
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