Special delivery: Foldable IOL injector systems offer advantages to surgeons

IOL injector delivery systems provide consistency of wound size and IOL placement.

IOL injection systems, once considered unreliable surgical tools, have improved in recent years, making them more attractive to cataract surgeons.

“Injectors are getting better and better,” ophthalmic surgeon Stephen S. Lane, MD, told Ocular Surgery News. “Within 5 years, I think every IOL that is used will be put in with some sort of insertion device. They offer several advantages,” he continued. “In addition to consistency of wound size, surgeons find these devices offer consistency of placement; IOLs unfold essentially the same way every time.”

Being able to predict IOL placement means surgeons can better standardize their procedures. “If you are using the same size incision all the time, there’s going to be less variability in the amount of induced astigmatism, for example,” Dr. Lane said. “You are able to determine your own surgeon factors so that you can take them into account to try and more uniformly perform surgery.”

Another advantage, Dr. Lane said, is that IOL injector systems probably hasten the procedure because the scrub nurse can do the loading of the injector and have it ready for the surgeon. “You can insert it without having to do lots of manipulations with the lens yourself, which can really waste time,” he explained.

Additionally, there is at least theoretically an increase in sterility. “I think it’s a more sterile situation, because you’ve isolated the lens from the external environment,” Dr. Lane said. “You do not have to worry about rubbing the lens on the sclera or the conjunctiva as you slide it through because it has been loaded under sterile conditions. As it is brought into the operative field, the only thing that would touch the external portion of the eye would be the cartridge. So, from a sterility standpoint, there’s less chance of it dragging bacteria from the environment through the incision into the eye,” Dr. Lane said.

An engineering challenge

The first injector delivery devices that were easy to use, safe and effective were for silicone plate IOLs. Devising injector delivery systems that would not traumatize a three-piece IOL design represented an engineering challenge. “Some of the early delivery devices would just sort of shoot the implant in any which way, and sometimes it would land posterior side up,” said Louis D. Nichamin, MD. “During the past 4 or 5 years, these delivery systems have improved dramatically, first with silicone and now with acrylic.” Like Dr. Lane, Dr. Nichamin said he thinks “everyone will be using them in time.”

Dr. Nichamin sees improvements in the way the IOLs are loaded and increased sterility as the main benefits to injector delivery systems. “The advantages are that they obviate the physical need to load and fold the IOL, and that the implant does not come in contact with any of the external conjunctiva, tear film or adnexa, where the risk of contamination exists. So, in theory, it is a more sterile way of inserting the implant,” he said.

Priscilla E. Perry, MD, said that her experience with injector delivery devices is representative of many surgeons, in that she became familiar and comfortable with injectors starting out with silicone IOLs. “The idea of inserting an implant with an injector as opposed to a manual type of folding inserter or forceps was really appealing to me with silicone lenses, so the transition to the acrylic lenses is really natural,” Dr. Perry said. “I think the injection is a more predictable way of inserting implants.” Approximately 85% of the IOLs that she implants are acrylic.

“Additionally,” Dr. Perry said, “with the injector, one knows that that the incision size is going to be a standard predictable size. I like that. I’m very concerned about any wound trauma or wound stretching, and I would rather have a system where the incision size was going to be predictable and could be planned for; the injector allows that possibility.”

According to Dr. Perry, the parameters that one looks at when evaluating an injector have been improved in every manufacturer’s system. “These parameters are how predictably and easily the lens can be loaded; how predictably and controllably the lens can be inserted; and what, if any, damage the lens is at risk for sustaining during insertion,” she said.

What’s out there

The Monarch IOL Delivery System and the recently released Monarch II cartridges are used for implanting Alcon Laboratories’ single-piece or multi-piece acrylic AcrySof IOLs. The newly designed Monarch II cartridge, combined with the durability and flexibility of AcrySof single-piece acrylic haptics, enables surgeons to implant the single-piece lens in the capsular bag in one step. The need to introduce a second instrument to dial the trailing haptic is eliminated; therefore, surgeon efficiency increases by reducing steps during the IOL implantation process. Alcon recommends loading the AcrySof lenses into the Monarch and Monarch II using forceps that have rounded, non-serrated blades such as the Duckworth and Kent DK-7710 holding forceps or equivalent. Monarch delivery systems consist of two parts: autoclaveable, reusable titanium handpieces and sterile, single-use cartridges. The original Monarch was intended to go through an incision size of 3.4 mm to 3.5 mm. The Monarch II goes through an incision size of 3.0 mm to 3.2 mm, according to Dr. Lane.

The Unfolder Sapphire Series Implantation System is used to implant the Allergan Sensar 6-mm foldable acrylic posterior chamber IOL. Dr. Perry pointed out that the AcrySof IOLs and the Sensar IOL are “totally different lenses so there are some differences in the injectors because of the inherent difference in the lenses.” She noted that the “Sapphire works as well as it does because Allergan had a long history of injector success with silicone lenses prior to introducing its acrylic lens.”

Meanwhile, Dr. Nichamin is sticking with silicone. “I use the Bausch & Lomb LI61U and its injector delivery system, the Mport, which, in my hands, is the most facile injector of any sort. I do use some acrylics when I think there’s a contraindication to the use of silicone, which is rare — maybe one out of every 10 lenses. Otherwise, I use the LI61U and the Mport, which is a simple syringe-style injector that allows complete delivery of the implant into the bag with one hand.

“It’s been very reliable, and soon Bausch & Lomb will introduce its Mport SI (small incision), which supposedly will go through an even smaller incision,” Dr. Nichamin continued. “Right now, I’m at about a 3.2-mm incision; with the Mport SI, I think I will be able to get down to 2.8 mm.”

Nothing is perfect

There are infrequent cases when surgeons say they opt for traditional forceps even when using foldable IOLs. “In the great majority of situations, the injector is the insertion system I use, but there are some instances where capsule integrity is compromised and I will choose to use a forceps,” Dr. Perry said. “In those cases, you can get more complete control and less tension on the capsule by placing an implant with a folding forceps,” she said.

No technology is without drawbacks. “There are some negatives,” Dr. Lane said. “Probably the main negative is that you have to be very careful how you load an injector. If you load the lens improperly, it is going to come out improperly and possibly damage the lens. I’m not saying it is either time consuming or difficult, but it is possible to load it incorrectly, and, if you load it incorrectly, it can cause a problem.”

What’s ahead

Chilean ophthalmic surgeon Jaime Zacharias, MD, is working with a powered foldable IOL injector. He reported on the device, in comparison to conventional manual IOL injectors, at last spring’s American Society of Cataract and Refractive Surgery meeting. The powered device was designed using state-of-the-art microelectric components. Prototypes were tested in vitro and in vivo. Dr. Zacharias reported that foldable IOLs were safely implanted with the electronic injector and that the device provided forward and reverse plunger displacement under operator control. He said the powered injector allows single-handed operation, keeping the opposite hand free to control the injection process with another instrument. He suggested that the use of a powered injector could improve the safety and efficacy of foldable IOL implantation.

For Your Information:

• Stephen S. Lane, MD, can be reached at Associated Eye Care, 232 Main St., Stillwater, MN 55082; (651) 439-8500; fax: (651) 439-5106. Dr. Lane has no direct financial interest in any of the products mentioned in this article. He is a paid consultant for Alcon and Bausch & Lomb.
• Priscilla E. Perry, MD, can be reached at 1310 N. 19th St., Monroe, LA 71201-5044; (318) 388-2020; fax: (318) 361-0914. Dr. Perry has no direct financial interest in any of the products mentioned in this article, nor is she a paid consultant for any companies mentioned.
• Louis D. Nichamin, MD, can be reached at Laurel Eye Clinic, 50 Waterford Pike, Brookville, PA 15825; (814) 849-8344; fax: (814) 849-7130. Dr. Nichamin has no direct financial interest in any of the products mentioned in this article. He is a paid consultant for Bausch & Lomb Surgical.
• Jaime Zacharias, MD, can be reached at Las Hualtatas 5951, Santiago, Chile; (56) 2-224003; fax: (56) 2-2207388.