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Techniques evolving globally to rescue weak capsules, fallen nuclei
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Ongoing innovations have made cataract surgery one of the most commonly performed and successful procedures in medicine. From advanced phacoemulsification platforms to a plethora of posterior chamber and anterior chamber IOLs, technological developments have raised the bar for safety, efficacy, predictability and stability.
Some surgeons are thinking outside the box to restore or augment capsular and zonular support, prevent lens nuclei from falling into the vitreous, retrieve fallen nuclei, and achieve safe and stable IOL fixation in eyes with insufficient capsules and irises.
Surgeons need to recognize potential problems early, before considering support or salvage strategies, according to John A. Hovanesian, MD, FACS, OSN Cataract Surgery Section Editor.
“The first rescue technique is to recognize as early as possible that you may have a compromised capsule and to try to prevent nucleus or any lens material from falling into the vitreous. That is done by constant vigilance,” Hovanesian said.
Mark Packer, MD, said that cataract surgery can be unpredictable because of unexpected issues such as trauma and various pathologies.
Ophthalmic surgeons are still looking for the right combination of intraoperative support devices and postoperative support, according to Ike K. Ahmed, MD, FRCSC.
Image: Ahmed IK
“There are those cases where you expect there to be problems and you’re all prepared, and then there are those cases where, suddenly, you need to do something different,” Packer said.
Ike K. Ahmed, MD, FRCSC, OSN Glaucoma Board Member, said the capsular bag can be an optimal location for IOL implantation in select cases.
“If the capsular bag can be salvaged, in my opinion, there’s no better place to put a lens in than the capsular bag,” Ahmed said. “That is the safest and the most biocompatible place to put a lens. The problem arises when we lose zonular support. Thus, a lens in the bag may not be stable.”
Posterior capsular rupture
Sadeer B. Hannush, MD, explained three basic approaches to managing a rupture in the posterior capsule or zonulysis before completely emulsifying the residual lens nucleus. The first approach is to inject a dispersive viscoelastic through the pars plana into the vitreous cavity to levitate the intact or fragmented nucleus into the anterior chamber.
Sadeer B. Hannush
“Then, with adequate protection of the corneal endothelium, finishing the emulsification in the anterior chamber after a generous amount of dispersive viscoelastic has been placed in the anterior chamber,” Hannush said.
The second approach is to inject viscoelastic and place a Sheets glide in the anterior chamber, behind the nuclear fragment after it has been raised into the anterior chamber.
The third approach is to insert the posterior chamber implant into the ciliary sulcus or capture it on the pupil first, after delivery of the cataract into the anterior chamber, and use it as a scaffold to prevent the nucleus from falling back.
The status of the anterior capsule also plays a role in determining the location and method of IOL fixation.
“For that to happen, the nuclear fragments have to be delivered into the anterior chamber and there has to be adequate anterior capsule left so that an implant can be placed in the ciliary sulcus and then the emulsification can continue,” Hannush said. “Or, in principle, you can go ahead and do scleral fixation of an implant, with glue or suture, and then finish the emulsification in the anterior chamber. This is a little bit counterintuitive because, as surgeons, we don’t think of implanting the lens before the nuclear fragments have been removed and emulsified completely. But these are three techniques.”
IOL scaffold technique
Amar Agarwal, MS, FRCS, FRCOphth, OSN APAO Edition Board Member, developed an IOL scaffold and a glued IOL scaffold technique to facilitate nuclear fragment removal in cases of capsular rupture. As Agarwal and Soosan Jacob, MS, described in past Ocular Surgery News articles, the technique involves implanting a three-piece foldable IOL above the iris or over the anterior capsule to serve as a scaffold in lieu of a Sheets glide.
“If you put both the haptics above the iris, the pupil is blocked by the iris. You can take your phaco probe and emulsify the nucleus pieces, no problem. Once the nucleus pieces emulsify, then you can assess how much capsular support you have and you can implant the IOL in the sulcus,” Agarwal said. The IOL can also be placed over the anterior capsule if enough support is available and the IOL scaffold technique done.
Agarwal has been using a new technique termed glued IOL scaffolding to provide support during nuclear fragment removal in such eyes with insufficient iris support and absent or insufficient capsular support for sulcus placement of an IOL. In this, he combines the glued IOL technique and the IOL scaffold technique for glued IOL scaffolding. (Figures 1-4.)
To perform the glued IOL scaffold technique, the IOL being used as a scaffold must be fixated in the posterior chamber, under the nucleus. The handshake technique is a safe way to fixate the IOL intrasclerally before the nucleus is emulsified and aspirated. The IOL can remain fixated in place, with the haptics glued under scleral flaps.
Figure 1. The posterior capsule is ruptured with a nuclear fragment present. No capsule is present. The pupil is dilated, so there is no iris support. A three-piece foldable IOL is injected inside the eye, under the nucleus. The glued IOL forceps are ready to grasp the haptic.
Figure 2. Scleral flaps are created, and the IOL is inserted.
Images: Agarwal A
Figure 3. The handshake technique is used to grasp the trailing haptic.
Figure 4. tip of the trailing haptic is caught with the glued IOL forceps and externalized.
The glued IOL scaffold technique creates an artificial posterior capsule.
“We are implanting the IOL and externalizing the haptics and tucking the haptics into a tunnel created with Gábor Scharioth’s similar technique,” Agarwal said. “The IOL is tucked fully into the eye. Now, the IOL cannot fall down. At the same time, the nucleus is above the IOL, so with a phaco handpiece I can … emulsify the piece beautifully and I will not have any trouble at all.”
The IOL scaffold technique is safe and easy to learn, Agarwal said.
“Anybody can do it. Anybody can implant the IOL,” he said. “It’s a very simple technique. There are no great surgical skills required in the IOL scaffold technique. One can easily perform it and get rid of dangerous complications where the nucleus might be sinking inside.”
The glued IOL technique involves no pseudophakodonesis.
“In other words, the lens does not move and the vitreous does not move. And when the vitreous does not move, there is no traction on the retina, so there is no cystoid macular edema or retinal tears. This is a big advantage in the glued IOL technique,” Agarwal said.
Packer described another technique that involves the use of 10-0 Prolene sutures to create a temporary scaffold that prevents the nucleus from falling in case of capsular rupture. Packer has not performed the technique.
“[The surgeon] just quickly passed sutures back and forth behind the lens, supporting the nucleus and then proceeding with phaco,” Packer said.
Pars plana vitrectomy
Hovanesian said cataract surgeons need to exercise judgment when lens material falls into the vitreous.
“The bottom line is that we need to ask ourselves, what is the best we can do for the patient … and at what point are we doing them a favor by trying to rescue the case?” Hovanesian said. “There are two directions that surgeons go when we get into trouble. One is to try to be heroic, and that leads us to try to complete steps that we probably shouldn’t. The other is to run away from our problems and to not completely clean up what we’re capable of cleaning up.”
John A. Hovanesian
For instance, in case of a dropped nucleus and intact anterior capsule, the surgeon should implant a sulcus-placed posterior chamber IOL to help the retina specialist who will perform vitrectomy.
“It’s one less step they’re going to have to do, and it allows the patient to see something even though there’s lens trapped in the vitreous,” Hovanesian said.
Hannush called for cases of fallen nuclei to be referred to a vitreoretinal surgeon, if possible.
“The eye should be closed and the patient referred to a vitreoretinal surgeon to do a pars plana vitrectomy and lensectomy,” Hannush said. “If there’s adequate capsular support, an implant can be placed in the sulcus, or I would suture the implant or scleral fixate it with fibrin sealant, knowing that this will relieve the vitreoretinal surgeon from having to address that, either at the time of the vitrectomy/lensectomy or at a later date.”
Hovanesian also advised cataract surgeons to refer patients to retina specialists for cases involving dropped nuclei.
“An anterior segment surgeon should not fish deep in the vitreous for pieces of lens material that have dropped,” Hovanesian said. “Generally speaking, even if we are doing pars plana vitrectomy, most anterior segment surgeons are not adept with a phacofragmatome, which is the vitrectomy instrument that fragments the lens in the posterior segment. The other problem is that most anterior segment surgeons don’t have a vitrectomy machine that has a high enough cut rate to safely get near the retina. We should leave that to our retina colleagues.”
Hovanesian said anterior segment surgeons should learn pars plana vitrectomy if they have the tools to do it.
“In recent years, it’s really become quite evident that we can do a better job with vitreous cleanup from the anterior segment by entering the eye through the posterior segment. What you should try to avoid is vitrectomy through your main phaco incision because you typically don’t get a lot of sealing,” Hovanesian said.
He said that during vitrectomy, fluid should ideally flow from the anterior chamber and toward the posterior chamber.
“You can do that best by having your vitrectomy in the posterior chamber and by having your fluid supply in the anterior chamber,” Hovanesian said. “Fluid has to exit in back and enter in the front. Then, the vitreous follows the fluid.”
Capsular tension rings, segments
Capsular tension rings and segments are essential to supporting compromised ocular structures, Hovanesian said.
“I think every anterior segment surgeon needs to learn how to use and have available some of the devices like capsular tension rings and segments in their OR,” he said. “We need to be courageous enough to do the right thing for our patients, rather than leave a compromised eye with what will become a decentered IOL and a complicated secondary procedure, to secure the lens in the eye as safely as we can.”
Capsular tension rings should be the go-to device for eyes that lack zonular support, Hovanesian said. He pointed to the Henderson capsular tension ring (Morcher) as an example.
“The main rule is to put it in as late in the case as you can because it makes everything easier for the cataract removal. The second rule is, when you’re putting it in, try not to stress the zonules in the area of weakness,” Hovanesian said.
The Henderson ring is suitable in cases with residual cortex, Hovanesian said.
“If you’ve got to put in the ring before you remove the cortex, you may want to consider the Henderson ring,” he said.
In cases with more than 2 or 3 clock hours of zonular weakness, the surgeon should consider using a capsular tension segment secured in the sclera or ciliary sulcus with an 8-0 Gore-Tex suture, Hovanesian said.
The Hoffman pocket is also a suitable method in complicated cases, Hovanesian said.
“What that will do is not only support the capsule, but it will center it as well,” he said.
Assessment of zonular weakness is multifactorial, not limited strictly to the amount of pathology in terms of clock hours, Ahmed said.
“The problem is that often you have much more diffuse disease, and it’s often hard to judge it on the clock hours,” he said. “It’s important to look and see how stable the bag is. Is the bag still very mobile at the end of the case? Those are some of the factors that we use. Is it a progressive condition? The age of the patient [is critical]. These are all factors that should go into making a decision as to whether a capsular tension segment is required or not.”
While capsular tension rings are helpful in cases of mild zonular disease, segments are appropriate for more acute zonular problems. Segments also support the capsular bag during phacoemulsification, Ahmed said.
Segments and Gore-Tex sutures are suited for postoperative support and securing the capsular bag to the sclera, Ahmed said.
“I think we’re still working on the right combination of intraoperative support devices and postoperative support,” he said. “The segment is sort of designed to accommodate both, and it certainly has done a good job. We’ll continue to try to think of new ways to look at this. It’s not so simple as just placing a device in the eye and securing it to the eye.”
Ahmed said that viscoelastics are also vital to supporting the capsular-zonular complex during phacoemulsification.
He described the potential benefits of using pharmacologic agents instead of tension devices to bolster the capsule and zonules.
“That would be very interesting just in terms of pharmacologic reinforcement of the capsular-zonular apparatus,” Ahmed said. “It could be injections. … There are a lot of different possibilities out there with regard to using either biomechanical, biochemical or electromagnetic or light therapy, whatever. There are a lot of different potentials to change the dynamic of the ocular structures, like lasers.”
Methods of IOL fixation
Placing posterior chamber IOLs behind the iris or in the capsular bag may not be practical or feasible in cases of insufficient capsule, trauma, aniridia, lens subluxation or loss of zonular integrity. Intrascleral haptic fixation may be a viable alternative in such cases.
Currently, the most popular technique among cataract surgeons of fixating a posterior chamber IOL in the absence of capsular support is suturing it to the posterior surface of the iris, Hannush said.
“My favorite technique, however, of placing a posterior chamber intraocular lens implant, either at the time of cataract surgery in the absence of capsular support or later, remains scleral fixation, either with suture or fibrin sealant,” he said. “I don’t necessarily like to suture to the back surface of the iris, and I don’t like to put in anterior chamber implants.”
In 2006, Packer and colleagues published an article in the Journal of Cataract and Refractive Surgery describing the Hoffman pocket, a method of scleral fixation that does not require conjunctival dissection. The technique uses a corneoscleral pocket initiated through a peripheral clear corneal incision. It eliminates the need for conjunctival dissection, scleral cauterization or sutured wound closure, the authors said.
“Although iris fixation of decentered IOLs is a popular technique, late-onset combined IOL-capsular bag subluxation resulting from zonular weakness or dialysis may be more easily repaired with scleral fixation,” the authors said in the article.
“That’s something we’ve been using. Those pockets are very nice because you avoid dissecting the conjunctiva,” Packer said.
Scharioth and colleagues explained sutureless intrascleral haptic fixation of a three-piece posterior chamber IOL in the ciliary sulcus in the Journal of Cataract and Refractive Surgery in 2007. The sutureless technique involves tucking the IOL haptics into scleral tunnels parallel to the limbus, with no suturing or gluing.
In 2008, Agarwal and colleagues introduced the use of fibrin glue to secure the scleral flaps under which the haptics are tucked.
“With a glued IOL, the advantage is that the lens is in the same position as your normal IOL should have been. That is one of the bigger advantages of the glued intraocular lens techniques compared to the [anterior chamber] IOLs. There are very good [anterior chamber] IOLs and there are very good designs also, but invariably with time, these lenses can create trouble later on in life,” Agarwal said.
Ahmed summarized the safety advantages of sutureless scleral fixation.
“The primary advantage is that no suture is required for fixation. Sutures have a tendency to break and cause dislocation,” Ahmed said. “Number two, the lens is sitting away from the iris. Anterior chamber lenses or iris-fixated lenses have some potential disadvantages of being in the proximity of the angle and of the iris. I think those are two big ones. I would also add that I think that centration and tilt are reduced with the technique that we use.”
Agarwal also pioneered the handshake technique, in which the surgeon transfers the lens haptics from one hand to the other to safely manipulate them in a closed-globe surgical setting.
“The handshake technique is a simple technique where you are using two glued IOL forceps which are an extension of your hands. And like you are doing a handshake, you are handshaking the haptic so that you can grasp the tip of the haptic,” Agarwal said. “Once you grasp the tip of the haptic, you can externalize the tip alone rather than externalizing from somewhere in the middle of the haptic and deforming the haptic.”
Packer said there are certain risks associated with the handshake technique, such as difficulty maintaining control of the implant. – by Matt Hasson
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For more information:
When is it appropriate to approach a fallen nucleus from the front or back, or let it go and have a vitreoretinal surgeon handle it?
Use IOL scaffold or spears to trap residual nucleus
An intact anterior capsulorrhexis permits sulcus fixation with optic capture of a three-piece implant. Employ the IOL as a protective scaffold once nuclear fragments are elevated above the iris; this prevents fragments from falling into the posterior segment through a broken posterior capsule. Either by visco-levitation through the pars plana or, preferably, with opposing forces applied through clear corneal paracenteses using Arbisser nuclear spears, residual nucleus is raised and then sandwiched between layers of dispersive ophthalmic viscosurgical device protecting both iris and endothelium.
Unless the anterior chamber is very crowded, the IOL can be inserted under the nuclear fragment and kept in the anterior chamber with the trailing haptic out of the incision covering the rhexis opening. Alternatively, the optic can be captured with both haptics entirely within the eye, hermetically sealing the posterior chamber from the anterior.
Lisa B. Arbisser
Slow-motion phacoemulsification of fragments can only be considered if there is no vitreous prolapse forward of the pupil. Ultrasound will not cut vitreous and risks retinal tear and detachment. Once the anterior chamber is clean, the IOL can be freed to deal with residual vitreous and cortex in the posterior chamber and then recaptured with haptics in the sulcus.
Alternatively, anteriorly prolapsed vitreous can be retracted back or the communication with the vitreous body amputated with the vitrector through a pars plana incision and the irrigation anterior through a paracentesis, leaving the captured optic in position. If the rhexis is not intact and the zonules or posterior capsule are not intact, I would favor a sulcus lens with iris or scleral fixation, but an anterior chamber lens may be easier to place and has yet to be shown to give worse outcomes. Keeping the two-chamber eye is a lofty goal, but preventing vitreous traction is the key to obtaining a good outcome.
Lisa B. Arbisser, MD, is co-founder of Eye Surgeons Associates in the Quad Cities area of Illinois and Iowa, and an adjunct professor at the Moran Eye Center, University of Utah, Salt Lake City. Disclosure: Arbisser has no relevant financial disclosures.
Implant posterior chamber lens and consult vitreoretinal surgeon
I recently encountered my first dropped nucleus in a patient who had multiple intravitreal injections for macular degeneration. There was fibrosis of the posterior capsule, but it is obvious one injection damaged the posterior capsule. As I started the hydrodissection, the nucleus just dropped. We placed a posterior chamber lens in the sulcus. We then asked the vitreoretinal surgeon to go through the pars plana and do pars plana lensectomy. That patient did well.
If the capsule is ruptured during a surgical procedure, then one can still often phaco the remaining lens material. A limited vitrectomy, if needed, can be done. And using Viscoat (4% chondroitin sulfate, 3% sodium hyaluronate, Alcon) behind the lens nucleus to support it or, in some cases, a Sheets glide, the nucleus can be removed with the phacoemulsification unit.
Walter J. Stark
Occasionally, it is necessary for the cataract surgeon to go through the pars plana to support the nucleus and bring it up into the anterior chamber so that it can be removed. If that is done, it should be done through an incision 3 mm posterior to the limbus through the pars plana. Our recommendation is to go ahead in those cases and implant the posterior chamber lens and either at that time or at a later time have the vitreoretinal surgeon evaluate the patient and determine whether or not pars plana lensectomy is needed for removal of the remaining lens nucleus.
If the IOL is not stable in the ciliary sulcus, then one can obtain pupillary capture of the lens and do a modified McCannel suture fixation of the IOL loops to the peripheral iris to support that lens so that it does not fall back into the vitreous cavity. It is important in these cases not to use a single-piece ciliary sulcus anterior to the capsule, which can cause problems with chafing of the iris and uveitis-glaucoma-hyphema syndrome.
Walter J. Stark, MD, is a cataract surgeon practicing at Wilmer Eye Institute, Johns Hopkins University Hospital, Baltimore. Disclosure: Stark has no relevant financial disclosures.