Cataract
July 2023

by Liz Hillman
Editorial Co-Director

There are many motives and methods for IOL exchange. While a rare need, the physicians who spoke with EyeWorld said it’s important to be familiar with the indications for exchange, removal techniques, and considerations for IOL replacement. “Thankfully, the need to perform an IOL exchange is relatively uncommon in modern ophthalmology,” said Samantha Schockman, MD.

Morgan Micheletti, MD, remembers IOL exchanges being portrayed as “a scary, complex, and challenging surgery” when he was a medical student. While these cases aren’t routine, he said that ophthalmologists are now more comfortable with the surgery. 

Joshua Teichman, MD, said the decision to exchange is a joint one between the surgeon and patient. “A surgeon who performs more IOL exchanges will have a low complication rate and likely offer this earlier than a surgeon who does not,” Dr. Teichman said. “It is important that those who implant IOLs more prone to dissatisfaction be comfortable with IOL exchange. When a patient is unhappy from something that is clearly attributable to the IOL and exchange has a reasonable chance of improving this, I think an exchange is warranted. It is important that other issues be ruled out first. If patients are unhappy with presbyopia-correcting IOLs immediately postoperatively, one can generally assume that this is not from posterior capsule opacification, and a YAG capsulotomy should be avoided. IOL exchange in the presence of an open posterior capsule increases the risk and may be surgically more challenging. One should be prepared to perform a vitrectomy in these cases, and if the capsular bag integrity is compromised, be prepared with a 3-piece IOL for sulcus placement and/or flanged double needle intrascleral haptic fixation (Yamane).”

Why exchange and when

According to the physicians, there are several reasons for IOL exchange: refractive miss, dysphotopsias, intolerance to presbyopia-correcting designs, dislocation/subluxation, IOL defects/damage/opacification, and secondary issues (e.g., corneal edema from AC IOLs, UGH syndrome, etc.). 

“If you know it’s a miss, and you know there is stability, and you know it’s not an unusual situation like post-RK, but for whatever reason you’ve had a refractive miss, you can exchange relatively early on,” Dr. Micheletti said. “Relatively early I would say is within a month. If they’re not improving and they have a documented refractive error that’s large, I would go back in pretty quickly.” 

If the patient is off by less than a diopter, the patient is a good candidate, and it isn’t a rotational issue with a toric lens, Dr. Micheletti added that he’d consider a LASIK enhancement instead of intraocular surgery due to the risks.

Dr. Schockman said when there is a mechanical or anatomical issue causing complications, the decision to proceed with an IOL exchange is relatively straightforward. “It can be less clear when an IOL exchange is warranted when the patient has visual complaints in an otherwise healthy eye,” she said. 

“When the patient is unhappy with their vision after cataract surgery, the surgeon should first make sure the correct IOL was placed, the IOL is in good position, and the eye is otherwise in good health,” Dr. Schockman said. “It is advisable to repeat IOL measurements for accuracy. Any other cause for the patient’s visual complaints should be ruled out. If there is dry eye, the ocular surface should be optimized. In the case of multifocal IOLs, the surgeon should allow adequate time for neuroadaptation to occur. Once a stable refraction has been demonstrated, laser vision correction can be considered in the case of a refractive miss. The surgeon should try optimizing the patient’s vision prior to deciding on an IOL exchange. If the patient continues to have problematic symptoms despite clinical optimization, a detailed discussion is warranted to weigh the benefits and risks of IOL exchange.”

Dr. Teichman said if an exchange is being considered for incorrect IOL power or toricity, he’ll proceed once a stable refraction can be obtained. If the exchange is due to intolerance of a presbyopia-correcting IOL, some consider waiting months for neuroadaptation. Dr. Micheletti said if a patient is extremely bothered by severe dysphotopsias due to a diffractive IOL from the day of implantation, “you likely need to intervene sooner rather than later.” 

“I do try to go back in pretty quickly, within the first 2–3 months,” he said, noting that sometimes it means switching up IOL technology. He noted that the patient must understand what they might be giving up if they opt to exchange an IOL that they’re not entirely happy with. 

“You have to find out what exactly is bothering the patient and, in the case of a multifocal, if they’re willing to give up that near vision that they’re getting,” Dr. Micheletti said. “Some of my patients think about it and say, ‘I’m happy with my near vision, I don’t want to go back to glasses, I can handle this.’ That’s a very different conversation from the patient who says, ‘I can’t live like this, I’m miserable.’” 

How to exchange 

Focusing on in-the-bag IOL exchange, Dr. Teichman shared his usual process. “If the previous surgery was less than 3 months prior, I generally reopen the wound with a Sinskey hook,” he said. “If later, I will create a new wound, making sure it will not connect to the previous wound, which can occasionally reopen creating a very large unstable wound. I favor a slightly larger incision for IOL removal. The endothelium should be protected with dispersive viscoelastic and space created with a cohesive OVD (using the soft shell technique of Steve Arshinoff, MD). 

“It is important not to fill the anterior chamber completely as one will require additional OVD to free the IOL in the next steps,” he continued. “Next, ideally at the haptic-optic junction, dispersive OVD is injected just under the anterior capsule to begin the separation of the anterior and posterior capsule to open the bag. This can be done with a 30-gauge needle bevel down or a flat LASIK cannula. Once the separation has begun, the usual OVD cannula can be used to propagate this. This step is a combination of viscodissection and gentle manual dissection at times. The goal is to open the capsule 360 degrees. The location of the densest adhesions varies by the haptic shape and may be the proximal or distal portion. Once the IOL is partially freed, OVD is inserted posteriorly to protect the posterior capsule. Once the IOL is completely freed, it is brought into the anterior chamber, and with good protection of the endothelium and posterior capsule, the IOL is cut using intraocular IOL cutters. This is best performed with the second hand holding the IOL using micro-instrumentation. I generally completely bisect the IOL, but other techniques exist, including creating a Pac-Man or twisting maneuvers. Some surgeons will insert the second IOL posterior to the first, prior to cutting the first, to protect the capsular bag.”

Dr. Schockman said having a plan and a backup plan (or two) prior to removal is important. “To remove an IOL from within the capsular bag, it’s critical to ensure viscoelastic material is used to completely free the haptics. There can be fibrosis and scarring around the haptics, and manipulation of the haptics before they are completely freed can result in zonular dehiscence or capsular rupture,” she said. “Gentle dissection can be performed, but attempts to rotate the IOL before the haptics are free should be avoided. In some instances, the haptics cannot be freed, and the surgeon may amputate the haptics and remove the optic only. A new IOL can still be placed in the bag 90 degrees away, if a toric IOL is not required.” 

Dr. Micheletti and Dr. Teichman also shared this advice about leaving a haptic, if it cannot be easily freed. Dr. Micheletti noted that sometimes cutting at the haptic gives the surgeon more flexibility that could lead to its removal during the case. 

Depending on the IOL material, the first IOL can be folded, cut, or removed whole, Dr. Schockman said, also mentioning the Pac-Man technique. Both Dr. Schockman and Dr. Micheletti discussed inserting the second IOL posterior to the original to act as a scaffold, protecting the capsule. Dr. Schockman also gave the tip of using enough viscoelastic to protect the corneal endothelium while cutting or folding the original IOL. 

“A second instrument, such as a Kuglen hook or spatula, can be used to keep the IOL away from the cornea while it is removed,” she said. 

Dr. Micheletti recently published about the “modified twist and out” technique.¹ With this method, once the IOL is in the anterior chamber with one haptic externalized, an additional paracentesis is made 180 degrees away from a side port and “the shaft of a 25- or 27-gauge cannula is threaded across the AC to connect these incisions.” According to the paper, this technique “frees both hands to use forceps within the incision, grasp the IOL, and rotate it around the forceps.” The technique allows for “smaller, more controlled movement than the large, 1-handed pronation” originally described. The technique is completed by withdrawing
the forceps-lens complex “with one efficient movement.”

What to exchange for

The second IOL for replacement depends on the reason for the original IOL’s removal as well as the patient’s age, other ocular comorbidities, the patient’s goals, and the patient’s anatomy, Dr. Schockman said. If the reason for exchange is a refractive miss, Dr. Teichman said he’ll exchange for the same IOL with the correct spherical power/toricity.

“If the patient is having an IOL exchange to replace a multifocal for a monofocal IOL due to visual disturbances, it may be a straightforward in-the-bag IOL exchange. In such a case, the most important aspect of the IOL exchange is to set realistic patient expectations prior to surgery,” Dr. Schockman said, adding later, “The decision on what IOL to insert is directly dependent on the best intraocular placement for a stable IOL. It is a good idea to have multiple types of IOLs available prior to surgery to allow for different scenarios.” 

For example, she said placing an IOL in the bag is optimal, but sometimes it is not a viable option, and the surgeon should have different IOLs available to them for these scenarios.

“It’s most important to ensure the patient’s primary problem with the IOL is addressed,” Dr. Micheletti said. “If the problem is a refractive miss, it’s straightforward. If the issue lies with the characteristics of the lens, then it’s a more complex discussion with the patient to determine the next best IOL for them. For example, one could change from a continuous range of vision multifocal to a segmented bifocal or to a non-diffractive EDOF or small aperture optic or, as a final fallback, to a monofocal IOL. The Light Adjustable Lens [LAL, RxSight] is also a good option. The adjustability of the LAL is beneficial in nailing the outcome and because the LAL is a 3-piece IOL, you can place it in the sulcus and optic capture in cases where the posterior capsule is already open. That does commit the patient to having to return more frequently for postop adjustments, so it’s important to discuss this possibility with the patient if the LAL is used as a backup intraoperatively for an unexpected capsular break.”

Final best practices

Dr. Micheletti mentioned the IOL calculators on ASCRS.org. “There are some calculators that can be used given the patient’s postop refraction and biometry to say what the power and orientation of the new lens should be,” he said. 

Dr. Schockman said her additional best practices for IOL exchange include obtaining an endothelial cell count (ECC) and a macular OCT. The ECC, she said, helps determine if an AC IOL is a reasonable option, if needed, and it allows for better counseling if there might be a future need for keratoplasty due to reduced endothelial function. Dr. Schockman also said that it might be necessary to remove an IOL and leave the patient aphakic.

“IOL exchanges can be challenging, and surgeons should optimize their chances at success by taking their time, improving visualization whenever possible, and having several backup plans at their disposal. The use of iris hooks for direct visualization can be invaluable,” Dr. Schockman said. 

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About the physicians

J. Morgan Micheletti, MD
Berkeley Eye Center
Houston, Texas

Samantha Schockman, MD
Cincinnati Eye Institute
Cincinnati, Ohio

Joshua Teichman, MD, MPH
Prism Eye Institute
University of Toronto 
Toronto, Canada

Reference

1. Duncan NB, Micheletti JM. Modified adaptation of the twist-and-out technique for intraocular lens exchange. J Cataract Refract Surg. 2022;48:1469–1471. 

Relevant disclosures

Micheletti: None
Schockman: None
Teichman: Aequus, Alcon, Allergan, Bausch + Lomb, Labtician Thea, Novartis, Santen, Shire, Sun Pharma

Contact 

Micheletti: morgan.micheletti@gmail.com
Schockman: sschockman@cvphealth.com
Teichman: josh.teichman@gmail.com