Alternative technologies to femto widen scope and accessibility of advanced cataract surgery

Alternative technologies to femtosecond laser-assisted cataract surgery may provide premium outcomes at more affordable prices. These new technologies may improve access to high-quality surgical care in both developed and developing countries.

“It is an exciting time because a number of new technologies are coming out that can potentially improve the results of cataract surgery at fairly affordable costs,” OSN Technology Section Editor William B. Trattler, MD, said.

In his view, the Malyugin ring (MicroSurgical Technology) was a recent non-automated device that has revolutionized cataract surgery by making challenging cases with a small pupil or floppy iris safe and manageable.

“This non-automated technology has made high-risk surgical cases become routine and has dramatically improved our results,” he said.

Source: William B. Trattler, MD

Trattler believes that recent technology alternatives to femto can play an important role in cataract surgery. They can help improve efficiency, which translates into less inflammation and potentially a faster visual recovery.

“Perhaps one of the biggest challenges of surgery is when patients feel their visual recovery is not progressing as fast as expected. The delay in visual recovery generates anxiety and the need for more frequent trips to their doctor’s office to determine why they are not seeing as well as expected. In some cases, family members have to request time off from work to bring the patient to the office, which is another burden. A wider access to technologies that speed visual recovery has numerous advantages for the patient, their families, the society and the environment, too,” he said.

miLOOP for lens fragmentation

One of the newest technologies is the miLOOP device (Iantech), designed to provide energy-free endocapsular lens fragmentation. A flexible, retractable, micro-thin nitinol wire is inserted into the capsule, opens up in a loop, wraps around the nucleus and, when retracted, bisects the lens. The process can be repeated to break the lens into four or more pieces.

The procedure helps manage dense cataracts, reducing the amount of phaco energy and making challenging procedures easier and safer.

“Less phaco energy results in less corneal edema and faster visual recovery. We use the miLOOP also in patients with endothelial cell issues, such as Fuchs’ corneal dystrophy, where you want to minimize phaco energy as much as possible,” Trattler said.

MiLOOP is, in his opinion, an exciting recent development in cataract surgery, “a huge revolution in the ability to perform small-incision surgery for patients with very dense cataracts.”

Trattler has been using the device for the past year, since its approval in the U.S., and is now participating in a multicenter retrospective study.

“We are including patients with all levels of cataracts, not just dense nuclei. We want to assess the impact of reduced phaco energy levels on corneal edema and speed of visual recovery,” he said.

In the U.S., the cost per case using miLOOP amounts to about $100. This may be a relatively small cost to the surgery center when performing surgery on refractive cataract surgery patients with dense cataract, including those receiving a toric or presbyopic IOL.

“These patients have high expectations, as they may be spending thousands of dollars, and expect a fast visual recovery,” Trattler said.

The device is being used by a growing number of surgeons in the U.S. Beyond patients with dense cataracts, surgeons are using the miLOOP in a variety of clinical scenarios in which this technology can help optimize the cataract procedure and potentially improve the speed of visual recovery, he said.

Zepto for capsulotomy

Zepto (Mynosys Cellular Devices) is a disposable system that is another alternative to femto, used to create a standardized capsulotomy of approximately 5.1 mm. The cutting element is a foldable nitinol ring enclosed in a silicone suction cup. It is inserted into the eye through a retractable pushrod that connects the ring with a console, which generates suction and then brief electrical pulses for cutting the tissue.

OSN Cornea/External Disease Section Editor Elizabeth Yeu, MD, considers the Zepto a valuable alternative to the femtosecond laser in specific cases. Accurate refractive outcomes require both precision in astigmatism reduction and predictability with the IOL power calculations. Approximately 50% of her cases involve advanced technology options to provide greater freedom from spectacles, and an automated capsulotomy, whether femtolaser-assisted or Zepto, ensures more predictable outcomes in her hands because of the more standardized effective lens position provided by a consistently centered and uniform capsulotomy.

“Since I started using the Zepto in February, it now provides an additional option for an automated capsulotomy and can be used in place of femto in my toric IOLs and toric presbyopia-correcting IOLs. I preferentially use FLACS when astigmatic keratotomies are being placed to reduce lower levels of corneal astigmatism, but in the setting of a toric lens, I can now use the Zepto to create the capsulotomy in those patients,” she said.

Zepto’s disposables are between one-third and one-quarter of the cost of a femtosecond patient interface, which results in a reduction of the cost per procedure. The capital cost is a fraction of the cost of a laser, and there can be a time-saving factor in favor of Zepto because there is no need to move the patient from one room to another.

“It eventually takes an additional 30 seconds to a minute over manual capsulotomy, and it is all done in the OR, which is a nice benefit,” Yeu said.

However, as a refractively minded surgeon, she would not advise anyone against investing in a femtosecond laser just because the Zepto is available.

“I would not say no to femtosecond laser because I do appreciate being able to have the live OCT, lens-softening patterns and the different functions that it offers. However, the Zepto is a great opportunity for those surgeons who are unable to have access to a femtosecond laser but are moving toward refractively oriented surgical outcomes,” she said.

Pearls for surgery

New adopters should be reassured that using the Zepto is not too different from injecting an IOL, which is something any cataract surgeon is well accustomed to, Yeu said.

“It requires some stabilization of the eye and some viscoelastic at the site of the incision to facilitate insertion. Once the Zepto is positioned, before applying the suction, make sure that the flange is fully opened and has a 360° contact with the anterior capsule. After suction has been achieved, wait an extra 2 seconds before applying the energy to create the capsulotomy, which only takes a fraction of a second to perform,” Yeu said.

Although the Zepto can go through a 2.2-mm wound, she recommended enlarging it to 2.3 mm for an easier, more ergonomic insertion.

The first cases should be eyes with a deep chamber and a well-dilated pupil to gain confidence before moving on to more challenging cases.

One limitation of the Zepto in its current form is that it provides only one capsulotomy size, but Yeu is confident that future upgrades will overcome this limitation.

“If I look at my own data, by using femto to create the capsulotomy, results show that we are 94% within 0.5 D of spherical equivalent refractive error. With manual capsulotomy, we are 86%. This shows that it is very important to have a standardized capsulotomy in order to achieve that refractive error outcome. If you can achieve a similar refractive predictability by using a lower-cost device, this will help surgeons to move forward and use more and more lenses for presbyopia,” Yeu said.

CAPSULaser

The CAPSULaser (Excellens) is a small, compact laser device for capsulotomy that can be mounted under any current operating microscope. A vital dye creates a chromatically selective target for the laser.

“It creates reliably circular capsulotomies in about 1 second. It is a great clinical tool that fits very well in between the manual and the femtolaser capsulotomy. It is also a great teaching tool because it helps the novice eye surgeon to approach safely one of the challenging steps of cataract surgery and gain confidence,” Pavel Stodulka, MD, PhD, said.

Not yet approved in the United States, the CAPSULaser is expected to receive the CE mark soon. Stodulka was one of the first users of the device and an investigator in the pivotal studies, in which 124 eyes were evaluated. Outcomes were good for both the circularity and completeness of the capsulotomy. He is now collecting data from the 18-month follow-up, as well as the results of a series of challenging cases, such as eyes with phakic lenses, corneal rings and corneal scars and those that underwent penetrating keratoplasty.

“Since the very beginning and first prototypes, I found it very straightforward and reliable. The procedure does not require any additional surgical time and patient manipulation. The patient lies underneath your current microscope, you stain the capsule with trypan blue, fill the anterior chamber with OVD, place the surgical contact lens over the eye, center and focus, push the foot switch for 1 second, and that’s it. I am sure surgeons will like this technology and that it will easily find its way into the market,” Stodulka said.

Advantages and limitations

The CAPSULaser only performs capsulotomies and does not have the added femtolaser benefits of lens fragmentation and corneal incisions. However, femtolasers have high purchase and maintenance costs and a high procedure fee related to the disposable materials.

“This, together with the time issue, the complexity and often the need for a dedicated room, is preventing a more widespread use of the femtosecond laser technology. The CAPSULaser was invented to somehow overcome those hurdles,” Stodulka said.

The capital cost is predicted to be around $70,000, there will be no click fee, and the disposables will be just a surgical contact lens and a dedicated trypan blue solution, fine-tuned for best interaction between the laser and the stained capsule.

The CAPSULaser has the advantage of performing capsulotomies of various diameters, in 0.1 mm steps, starting at 4.5 mm and up to 6 mm. The surgical setup and the procedure itself are similar to manual cataract surgery, but it involves a laser, which is easy to explain and appealing to the patient, Stodulka said.

“I believe this is quite an advantage over the Zepto. I have limited experience with it and I must admit that it works very well, but I found it surprisingly difficult to explain to the patients that they would have to pay more for a wire that I put into their eyes to cut a very circular something. If you tell them you use a laser for a certain surgical step to make it more precise, this is something they understand and like to hear,” Stodulka said.

There are a few limitations to the system, one being the pupil size. The CAPSULaser cannot be used with small pupils unless they are enlarged with iris hooks or some other device. Scarred corneas that are not sufficiently or evenly transparent might also be a problem, but the laser can be used safely in eyes after PK, placing the capsulotomy in the central, clear part of the graft, avoiding the edges.

Stodulka intends to introduce the CAPSULaser as a routine part of his clinical practice for patients who are not willing to pay the premium price for a femto technology but still want to be implanted with a premium lens.

“Our plan is to structure cataract surgery into three different categories: manual, CAPSULaser and a femto,” he said.

Surgery in developing countries

A low-tech surgical technique that is now widely used in the developing world is manual small-incision cataract surgery (MSICS).

“It allows us to remove the natural lens without using phaco through a 6.5- to 8-mm wide sclerocorneal tunnel. The capsulotomy can be a standard capsulorrhexis, a can opener or a linear V-shaped capsulotomy, depending on the cataract. Once the capsulotomy is made, the lens is subluxated into the anterior chamber and then removed using a lens loop or fluidic movements to force it out of the wound. The remaining cortex is removed with a Simcoe cannula, and the flow rate can be determined simply by moving the bottle up higher or lower on the pole. Once the cortex is removed, a lens is inserted though the main wound. Given the large size of the incision, a single-piece PMMA lens, which is used widely throughout the developing world, can be utilized,” John Clements, MD, said.

Unlike the limbal wound of standard extracapsular cataract extraction, the wound created for MSICS is watertight and does not require sutures in many cases.

“The design of the scleral corneal tunnel is such that it creates a one-way valve. The postoperative results are quite good, with good clear corneas and good vision the day after the procedure,” Clements said.

During a 3-year stay in Angola, Clements performed about 3,000 of these surgeries annually.

“It is an elegant procedure when done well, and it is minimal in terms of technology requirement. I performed it throughout Angola in various conditions, including outposts where there is no glass on the windows, no electricity and very little in terms of running water. And yet the surgery can be performed with good results,” he said.

Integrating MSICS

Now, at the Casey Eye Institute in Portland, Oregon, Clements still uses this technique for difficult cases, such as black nuclei that are so dense that it would be difficult to emulsify by phaco, as well as a rescue technique in cases of zonular loss or vitreous loss during residents’ surgical training.

In 2007, Ruit and colleagues published a study comparing the efficacy and visual results of phacoemulsification vs. MSICS performed in Nepal. At 6 months, results were identical.

“These were all relatively dense lenses, and it is difficult to say that results would be always equivalent, but MSICS is a great option that should become part of our training programs. We are actively teaching our resident doctors here how to perform it. It is a good surgical technique for cataract surgeons to have in their tool bag for difficult cases, and certainly it is a very portable skill that allows us to be good global citizens in terms of fighting preventable blindness around the world,” Clements said.

“We have been looking in recent years at ways to incorporate low-cost techniques like MSICS into low-income clinics and underserved communities in the U.S.,” said Brenton Finklea, MD, who spent time working in Africa and southern Asia with the Wills Eye Global Ophthalmology Fellowship Program. “However, within our system, their accessibility and sustainability are lost through the fees of the OR, the staff for the OR and the anesthesiology team,” Finklea said.

Technologies and materials are, in the current system, only a minor part of the overall cost of surgery, he explained.

“We could save by doing in-office procedures under just oral benzodiazepines and local anesthesia. This method would be a challenge in absence of general anesthesia because MSICS requires a retrobulbar or peribulbar block. The block can be uncomfortable and may not be well tolerated in the Western population,” he said. “Even more limiting may be medical-legal hurdles for performing surgery in such a setting.”

A first step will be to educate practitioners about these procedures and encourage surgeons to incorporate them into their arsenal for specific candidates.

“Once MSICS has gained acceptance as a high-quality procedure, the next step would be finding ways of developing a system where this technique could be used to offer low-cost surgery to individuals in need,” Finklea said. – by Michela Cimberle

• References:
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• Hooshmand J, et al. J Cataract Refract Surg. 2018;doi:10.1016/j.jcrs.2017.12.027.
• Ianchulev T, et al. Br J Ophthalmol. 2018;doi:10.1136/bjophthalmol-2017-311766.
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• For more information:
• John Clements, MD, can be reached at Casey Eye Institute, 3375 SW Terwilliger Blvd., 4th Floor, Portland, OR 97239; email: johneyemd@gmail.com.
• Brenton Finklea, MD, can be reached at Duke Eye Center, 2351 Erwin Road, Durham, NC 27705; email: brent.finklea@gmail.com.
• Pavel Stodulka, MD, PhD, can be reached at GEMINI Eye Clinic, U Gemini 360, Zlin, Czech Republic; email: stodulka@lasik.cz.
• William B. Trattler, MD, can be reached at Baptist Medical Arts Building, 8940 N. Kendall Drive, Suite 400-E, Miami, FL 33176; email: wtrattler@gmail.com.
• Elizabeth Yeu, MD, can be reached at Virginia Eye Consultants, 241 Corporate Blvd., Suite 210, Norfolk, VA 23502; email: eyeu@vec2020.com.

Disclosures: Clements, Finklea and Stodulka report no relevant financial disclosures. Trattler reports he has a financial interest in Iantech and Mynosys. Yeu reports she is a consultant for Mynosys, Alcon, Johnson & Johnson, Lensar and Zeiss.

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