Innovation in IOL Injectors

Injectors may be used only briefly but they play an integral role in the safety, efficiency and visual outcomes of your cataract surgeries.

By Desiree Ifft, Contributing Editor

IOL injectors make only a brief appearance during cataract surgery, yet their impact on the safety and efficiency of the procedure is significant. Injectors play a role in vision outcomes as well, as they aid surgeons in minimizing surgically induced astigmatism by delivering lenses through increasingly smaller and smaller incisions. These important tools have improved incrementally over the years, but the most recent advances — preloaded devices and an automated option — represent major innovation.

Prior to the introduction of injectors, problems during IOL implantation were common. Rigid PMMA lenses and some of the first foldable lenses had to be manually folded and placed in the eye with forceps. The use of forceps often damaged the IOL. The procedure also required large incisions, which often had to be sutured. Manual folding required a certain level of skill and presented additional room for error. An uneven “taco” fold could necessitate enlarging an already large incision. Assistive devices became available to help standardize the proportions of the fold, but none eliminated the need for handling the IOL with forceps nor did they address the need for a more controlled or consistent insertion into the eye.

Today’s Injectors Add Control to Small-incision Surgery

Most IOL injectors work with a disposable cartridge into which the IOL is loaded after it’s removed from the packaging. The cartridge is then connected to a reusable handpiece with a plunger or screw mechanism that advances the IOL to its folded position and then into the eye. While today’s injector systems share those same primary components, other aspects have been introduced or upgraded in different ways over the years. For example, “Screw-type mechanisms require two hands but safely limit the speed at which the IOL can advance,” says Donald Serafano, MD. “Plungers advanced by thumb pressure may require only one hand, but the plunger can be advanced at difficult-to-control speeds, often resulting in damage to eye structures.”

Aaren Scientific’s Aero Injection System, designed to deliver the company’s three-piece hydrophobic acrylic spherical and aspheric IOLs, features a titanium handpiece with a small-thread screw mechanism. According to marketing manager Kim Dyer, “Surgeons like the smaller threads because they allow a slower and more controlled delivery of the lens. A larger knob at the end makes handling easier. The cartridge is designed for easy loading and folds the lens so it comes out co-planar with the haptics pointing in the right direction for placement in the capsular bag.”

Injectors are a critical piece of the procedure. The only product that stays with the patient is the IOL, and the delivery system is responsible for getting it there.

—Paul Soye, Cataract Surgery Franchise Head & Vice President of R&D, Alcon

Abbott Medical Optics’ Silver Unfolder handpiece contains a soft tip that protects the surfaces of its three-piece silicone lenses and fosters controlled delivery. Abbott’s Emerald Unfolder incorporates a push rod designed to prevent the haptics of the three-piece acrylic IOLs from engaging with the rod during implantation. The company’s Ultra and Platinum series insertion systems for use with the one-piece acrylic Tecnis lens have rear-loading, rather than winged, cartridges to enhance ease of use. In addition, “The Ultra has an improved lubricious coating applied to the inner lumen, which allows increased compression of the IOL,” Abbott manager of public affairs-communications Daniel Wawrzyn says. “It also includes improved folding features to reduce the potential for IOL damage during loading. The Ultra delivers the IOL through a 2.8-mm incision, while the Platinum delivers the lens through a 2.2 to 2.4-mm incision.”

In discussing Alcon’s IOL injectors, Paul Soye, cataract surgery franchise head and vice president of R&D, says, “On the surface, all IOL delivery systems may look the same, but in our experience that couldn’t be further from the truth. The injector has to work hand-in-glove with the material of your IOL and indeed the rest of your cataract surgery products.” The company introduced its original Monarch delivery system in 1998, and has since replaced it with the Monarch A-D models, which are used to implant the AcrySof line of lenses, including the IQ aspherics. Vice president of development, intraocular lenses, Steve VanNoy described the Monarch and its letter series cartridges as “state of the art in control and incision size, providing surgeons with flexibility for both incision size and location.” The D cartridge’s reduced-profile nozzle enables lens insertion through a 2.2 to 2.4-mm incision.

All of the products designed in the aforementioned injector style contribute to an improved procedure, according to Larry Patterson, MD. “They’ve evolved to a point where they’re much more foolproof than in the past. While some surgeons still load their own cartridges, I no longer see a need for that. I primarily use SofPort IOLs and the SofPort easyLoad Inserter (Bausch + Lomb) and the OR techs prepare the injector for me. In contrast to the ‘old days’ when foldable silicone IOLs tended to come out of the cartridge and pop open way too quickly, the easyLoad Inserter allows me to deliver the IOL in a very controlled manner. The lens is inserted into the eye flat, so very little maneuvering or manipulation is necessary. That planar delivery is especially important in cases where I don’t have a lot of room to work or when I encounter a torn capsule and need to have the implant go smoothly into a specific spot.”

Market Moves Toward New Injector Technologies

The SofPort easyLoad Inserter was the first available in the United States that allows an IOL to be implanted without the optic or haptics being touched. The lens comes completely contained in a lens retainer that is snapped onto a loading deck on the injector handpiece. Two other no-touch systems have since become available, the iSert from Hoya Surgical Optics and the AcrySert from Alcon.

“Our manually loaded injectors are still in use, but Hoya has taken the position as a company to reside mostly in the preloaded space,” says Anthony Belli vice president of U.S. sales. The company’s preloaded injector, the iSert for implanting the Hoya 230 (UV-absorbing, clear) and 231 (blue light-absorbing, yellow) three-piece, aspheric hydrophobic acrylic IOLs, was approved by the FDA in 2009. An iSert that is preloaded with the company’s one-piece, aspheric hydrophobic acrylic IOLs, the 250 (UV-absorbing, clear) and the 251 (blue light-absorbing, yellow), recently gained FDA approval and will be available to surgeons by the end of this year. The new iSert delivers the one-piece lenses through a 2.2- to 2.3-mm incision.

“The manually loaded injectors most surgeons use today provide fairly reproducible IOL insertion, but they still require the surgeon or technician to perform some potentially troubling steps,” says Peter Menger, MD, FACS. “The Hoya iSert product has eliminated those steps. It properly delivers an undamaged IOL within the confines of the modern incision size requirement.” Dr. Menger cites several advantages of a preloaded injector system. “An inserter that sequesters the lens from manipulation delivers a virgin, untouched IOL. Efficiency and reproducibility are improved, and there’s no learning curve on the part of the technician or surgeon. I’ve been using the iSert since 2009 and am eagerly anticipating the newest preloaded version for the one-piece Hoya IOLs.”

“The IOL is placed into the iSert injector system at the time of manufacture,” Belli explains. “That means the lens remains pristine. It is never touched by human hands. The iSert is also a single-use, disposable device, which enhances OR protocols with aseptic technique.”

Alcon’s AcrySert C preloaded injector, designed to implant the AcrySof IQ aspheric IOL, is also entirely disposable. “We’re differentiating our insertors just as we have our lens designs,” Van Noy says. “Preloaded is a hallmark in that approach.”

Abbott has launched its disposable Tecnis iTec preloaded insertion system internationally. “The device was developed to eliminate IOL loading errors, and improve sterility management and operating room efficiency,” Wawrzyn says. The Tecnis iTec preloaded system contains a one-piece acrylic IOL preloaded into the handpiece body for delivery through a 2.2 to 2.4-mm incision. “The IOL is pre-positioned in the insertion system at the factory,” Wawrzyn continues. “This eliminates surgeon handling of the IOL, and the added efficiency greatly improves the usability of the device and reduces the risk to the patient and the risk of damage to the IOL.”

Aaren Scientific is preparing to file with the FDA for approval of a three-step disposable preloaded injection system for its line of monofocal and toric hydrophobic acrylic IOLs. One of the goals in development was that the device require as few steps as possible for the technician or surgeon. “The fewer steps involved, the more controlled the environment,” Dyer says.

In addition to the AcrySert C and future preloaded injectors, Alcon is approaching IOL insertion technology from another direction as well. “We’re investing in injector technology and innovation to address unmet needs,” Van Noy says. Toward this end, the company introduced the Intrepid AutoSert IOL Injector, the first automated IOL delivery system. Coupled with the company’s Infiniti Vision System phaco platform and the Centurion Vision System, the AutoSert is operated with the foot pedal. “This is an example of modifying the phaco machine so it can work in concert with your injector and other equipment,” Soye says. Associate director of R&D David Downer adds, “AutoSert gives surgeons the best of both worlds — rapid delivery and control.”

Dr. Serafano describes how the AutoSert works. The IOL is loaded into the disposable Monarch C or D cartridge, and the cartridge is loaded into the specialized AutoSert handpiece. The plunger speed is preset by the surgeon and is divided into three stages: a push of the foot pedal initiates the initial velocity (1.7 mm per second is his preference) that advances the IOL to the ready position; a one-second pause to allow the IOL to conform to the cartridge nozzle and for the surgeon to assess the situation; and final velocity (linear 1.2/3.2 mm per second is his preference), which advances the plunger and moves the IOL into the eye. “The whole process is controlled with the foot pedal, making this a one-handed inserter. So I can use my second hand to stabilize the position of the eye,” Dr. Serafano says.

Expect Future Innovations

IOL implantation may evolve in a variety of ways in the near future, but preloaded devices will continue to be a focus. “The expectation is that preloaded systems will ultimately become the preferred method of delivery because of the added convenience and efficiency associated with delivery, along with the reduced risk of damage to the IOL and elimination of handling errors that can occur during loading and folding of an IOL,” Wawrzyn says. Alcon’s Soye reiterates the overall importance of continued innovation in lens insertion systems. “The refractive outcomes of cataract surgery today are better than ever because of small incisions, high-quality IOL materials and optics and delivery systems that act in concert with them. Injectors are a critical piece of the procedure. The only product that stays with the patient is the IOL, and the delivery system is responsible for getting it there.” ◊