May 2019

IN FOCUS

Technology & Innovation
A storm of innovation
How technology improves cataract surgery outcomes


by Chiles Samaniego EyeWorld Contributing Writer


Toric IOL placed perfectly on the refractive capsulotomy nub created by the LENSAR IntelliAxis-L system

Dr. Weinstock performs heads-up 3D cataract surgery with the NGENUITY system.
Source (all): Robert Weinstock, MD
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Juvene IOL immediately after implantation

Deployment of miLOOP under anterior capsular edge
Source (all): Summit Garg, MD

It is amazing to reflect on how rapidly cataract surgery continues to evolve,” Kendall Donaldson, MD, told EyeWorld. “Surgery continues to become less traumatic as we reduce energy put into the eye, ultimately increasing safety for patients while increasing the rate of visual recovery.
“In addition, refractive outcomes continue to improve thanks to advances in technology.”
As cataract surgery transitioned into a refractive outcome-driven procedure over the
last decade, the field has seen what Robert Weinstock, MD, called “a storm of innovation and technological advances.”
EyeWorld corresponded with Dr. Donaldson and Dr. Weinstock, as well as Sumit (Sam) Garg, MD, and Bryan Lee, MD, to find out what technological advances they use in their respective practices and how these technologies have improved their cataract surgery outcomes.

Advancing today’s technologies

Some advances have improved on existing technologies. Dr. Weinstock said that the LENSAR femtosecond cataract surgery laser (LENSAR) “has advanced tremendously with iris registration software to eliminate cyclotorsion error. By using preoperative imaging systems such as the Pentacam [Oculus], the Nidek OPD [Nidek], or the Cassini Total Corneal Astigmatism [Cassini Technologies], infrared images can now be sent directly and wirelessly to the LENSAR laser for a quick iris registration process once the patient is docked under the laser.”
Dr. Weinstock uses this technology to improve astigmatic corrections by ensuring the correct axis for arcuate incisions and also customizing the capsulotomy’s shape to include marks useful for orienting a toric IOL implant.
“Other advances in this platform are automatic nuclear density grading software applications to provide the most appropriate fragmentation pattern depending on the density of the nucleus, which is imaged by the Scheimpflug imaging system,” he said.
“We have the CATALYS femtosecond laser [Johnson & Johnson Vision],” Dr. Garg said. “FLACS [femtosecond laser-assisted cataract surgery] is particularly useful for dense cataract cases and for those with comorbidities such as Fuchs’ dystrophy and pseudoexfoliation. Also, the astigmatic incisions are much more precise than what I can accomplish freehand.”
Dr. Lee offered a contrasting opinion on FLACS. “There is no good evidence that the femtosecond laser improves phacoemulsification refractive outcomes or safety,” he said. For intumescent cataracts, he occasionally employs the Zepto capsulotomy system (Mynosys Cellular Devices), a device consisting of a thin nitinol wire loop that delivers heat to cut a consistent, perfectly round capsulotomy. “This capsulotomy happens faster than a femtosecond laser, which gives less time for liquified cortex to interfere with the cut when the capsule is under pressure.”
Phaco machines have also seen advances. Dr. Donaldson said that these machines now have more efficient fluidics, with custom energy cycles such as modified burst and pulse settings, and improved machine tubing that allows optimization of phaco parameters.

Advances in biometry

One existing technology that has steadily improved through the years is the biometry device. All the physicians interviewed for this article cited the IOLMaster 700 swept source OCT biometer (Carl Zeiss Meditec) as one of the more significant innovations. In addition to working with almost any grade of cataract and improving accuracy, the device incorporates the latest IOL calculation formulas created by experts such as Warren Hill, MD, and Graham Barrett, MD.
These formulas, Dr. Weinstock said, improve on existing formulas, incorporating artificial intelligence into the nomograms that drive intraocular lens power selection.
Dr. Donaldson added that the IOLMaster 700 “provides an image of the macula that is a very helpful screening tool for macular pathology in preparation for cataract surgery.”
Dr. Garg noted that the IOLMaster 700 can also be combined with the CALLISTO eye system (Carl Zeiss Meditec) to provide a reference image to guide toric IOL placement.
Acknowledging these advances in biometry, Dr. Lee noted that “[t]he question is, which technology will do the best job of measuring the posterior cornea? And that is something that will require more research to determine.”

Intraoperative advances

Ultrasound energy is one intraoperative parameter that has been the target of improvement for a number of technologies. “I have enjoyed using both the femtosecond laser and the miLOOP device [Carl Zeiss Meditec] to help reduce the amount of ultrasound energy I use, particularly during dense cataract cases,” Dr. Donaldson said. “Both devices help pre-fragment the lens in preparation for phacoemulsification.”
Like the Zepto, the miLOOP consists of a nitinol ring but is inserted into the lens capsule to bisect and chop the cataract.
“The miLOOP is useful for the very dense lens,” Dr. Garg agreed. “It allows for segmentation of very hard nuclei with relatively little effort.” In his experience, the miLOOP helps in cases in which even the femtosecond laser was not sufficient to fragment the dense nucleus. “Additionally, it allows for easy cortical removal as the process of deploying the miLOOP loosens cortex from the capsular bag,” he said.
Dr. Lee noted that the miLOOP can stress the zonules, and he doesn’t use it for cataracts with weak zonules, which is often the case for the type of dense cataracts the miLOOP is used for.
Intraoperative precision is an obvious target for improvement. Dr. Weinstock uses the NGENUITY 3D Visualization System (Alcon), recently combined with other technologies such as the ORA System (Alcon). “This allows for a much more efficient and heads-up oriented procedure, which everyone in the room can participate in and add value to,” he said.
Dr. Donaldson also uses both the ORA and the CALLISTO to help orient toric lenses. “The ORA is also particularly helpful for post-refractive cases,” she said. “I have become much more aggressive with astigmatism correction over the past decade, especially with regard to the correction of against-the-rule astigmatism,” subsequently improving refractive outcomes overall.

Postoperative adjustments

One way to hit refractive targets and achieve optimal outcomes is to broaden the range of focus, reducing the need for pinpoint accuracy. Dr. Lee mentioned the AcuFocus IC-8 (AcuFocus), a pinhole monofocal implant undergoing a clinical trial that he said “should provide some range of vision without the type of night symptoms that current MFIOLs and the Symfony [Tecnis extended depth of focus IOL, Johnson & Johnson Vision] cause.”
All the doctors look forward to technologies that will allow them to modify sphere and cylinder postoperatively, hitting their targets after the fact. “This will be a huge advantage to cataract and refractive surgeons alike, as they are now able to easily make adjustments and enhancements to patients postoperatively without an additional surgical procedure or intraocular lens exchange,” Dr. Weinstock said. “The promise of 20/15 vision for all patients is certainly on the horizon with technologies like this in development.”
Among these technologies, the Light Adjustable Lens (RxSight), already approved by the FDA, is “the initial player in this new arena,” Dr. Donaldson said. Other technologies are forthcoming.
She said there are several forms of component IOLs in development. These IOLs have exchangeable optic segments to allow modification from monofocal to multifocal and vice versa as well as adjustment to refractive error postop.
“Eventually, refractive indexing will allow us to modify the refractive error with a laser postoperatively; however, we may still be several years away from implementing this technology in our everyday clinical practice,” she said.
Dr. Garg described the Juvene fluid-filled lens (LensGen), one example of a modifiable component IOL. According to Dr. Garg, the IOL has a modular design that employs a dual optic principle—one fixed, the other fluid-filled—and has delivered up to 3 D of accommodation in early trials.

Improving technology improves outcomes

All these technologies combined “cumulatively improve cataract surgery outcomes for our patients,” Dr. Weinstock said. “[I]f you take all of these advances in our field and use them together in a process it translates into a more refined, safer, and predictable surgery and outcome for the patients.”
These advances allow surgeons to be more accurate in their outcomes, and “when combined with diligent preparation of the ocular surface, refractive surprises are less apt to occur,” Dr. Garg said.
Providing context for these advances, Dr. Lee noted that “history has proven the brilliance of Charles Kelman’s innovation of phacoemulsification. It is still the best way to break up and remove a cataract more than 50 years after its introduction,” he said.
Fortunately, surgeons “have gotten better and better at picking the correct IOL and making cataract surgery a true refractive procedure.”
“The next step will be improved ability to refine outcomes after phaco and improving range of vision with fewer optical trade-offs,” he added.
“[O]ur technology has allowed us to keep up with progressively increasing patient demands and expectations, in most cases,” Dr. Donaldson said. “Industry has worked very closely with surgeons to continually improve IOL technology, phaco technology, and diagnostics that help us best prepare for cataract surgery. Spectacle independence has become a major factor in how patients measure surgical success. The technology that we have available to us helps us achieve this goal for our patients, making our job as surgeon easier and more satisfying.”
 

At a glance

• The last decade has seen “a storm of innovation and technological advances” attending cataract surgery’s transition into a refractive outcome-driven procedure.
• Advances to existing technologies such as femtosecond laser platforms and phacoemulsification machines along with new technologies improve surgeons’ ability to carry out each step of the cataract surgery procedure with a high degree of accuracy and precision while reducing risk.
• Cataract and refractive surgeons alike look forward to and will benefit from
technology that will allow them to modify sphere and cylinder postoperatively.

Contact information

Donaldson
: KDonaldson@med.miami.edu
Garg: gargs@uci.edu
Lee: bryan@bryanlee.pro
Weinstock: rjweinstock@yahoo.com

About the doctors

Kendall Donaldson, MD
Professor of clinical
ophthalmology
Bascom Palmer Eye Institute
Plantation, Florida

Sumit (Sam) Garg, MD
Vice chair of clinical ophthalmology
Gavin Herbert Eye Institute
Irvine, California

Bryan Lee, MD
Altos Eye Physicians
Los Altos, California

Robert Weinstock, MD
The Eye Institute of West Florida
Largo, Florida

Financial interests

Donaldson: Alcon, Allergan, Bausch + Lomb, Bio-Tissue, Johnson & Johnson Vision, Sun Pharmaceutical, Shire, Kala Pharmaceuticals, Eyevance, Lumenis, Carl Zeiss Meditec
Garg: Johnson & Johnson Vision, LensGen, Carl Zeiss Meditec
Lee: AcuFocus, Carl Zeiss Meditec
Weinstock: Alcon, LENSAR, Carl Zeiss Meditec

A storm of innovation How technology improves cataract surgery outcomes A storm of innovation How technology improves cataract surgery outcomes
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