Surgeons share experiences, pearls for meeting challenges of sutureless scleral IOL fixation

In the absence of a lens capsule that can support an IOL, sutureless scleral fixation of the lens is an attractive option, without the risk of suture deterioration over time. But the fixation must be secure for the mostly three-piece posterior chamber lenses with extremely flexible haptics.

Amar Agarwal, MS, FRCS, FRCOphth, OSN APAO Edition Board Member, likens sutured IOLs to a broken camera lens that has been sutured to the lens body. “You will not be able to take good quality pictures because the lens will move with the lens body,” he said. “Similarly, by suturing an IOL to the eye, the lens will move with the eye, resulting in pseudophakodonesis.”

To remedy this problem, Agarwal has popularized a surgical technique over the years that uses intrascleral haptic fixation of an IOL with fibrin glue to seal created scleral flaps. “A glued IOL inserts the lens into an intrascleral (Scharioth) pocket and then glues everything down,” he said. “This way, the IOL is fixed into the eye and moves as one unit. The quality of vision is extremely good.”

Agarwal said the mechanics of a glued IOL can be demonstrated by viewing slow-motion video of the eye. “You will see that the lens is rock steady and that there is no movement,” he said.

Image: Hovanesian JA

Detection of pseudophakodonesis is another important aspect of a slow-motion recording. “A high frames-per-second recording of a glued IOL does not demonstrate pseudophakodonesis,” Agarwal said. “This can be attributed to the intrascleral tucking of the haptics that prevents any movement of the IOL.”

The main surgical skill required when performing glued IOL surgery is to externalize the haptics through a sclerotomy. To achieve this, Agarwal developed the handshake technique, in which two glued IOL forceps are used inside the eye.

“One forceps holds one haptic and transfers it with a handshake to the other glued IOL forceps,” Agarwal said. “This is continued until the tip of the haptic is caught by one of the glued IOL forceps, at which point the haptic can be externalized without breaking the haptic.”

Agarwal said the handshake technique has “made life very easy for the glued IOL surgeon, as one can perform the surgery faster and easier.”

However, “it is crucial to grab the haptic with the glued IOL forceps from the tip and not from anywhere else down the entire length of the haptic,” Agarwal said.

Good track record

Sutureless IOL surgery, in general, “has an established track record in terms of safety, longevity and stability inside the eye that is now fairly well proven, both abroad and in the United States,” OSN Cataract Surgery Section Editor John A. Hovanesian, MD, FACS, said. “To some extent, we can define the lens position with these sutureless lenses as well.”

On the other hand, technique is important for any type of IOL fixation without capsular support. Still, in his hands, the sutureless glued IOL technique popularized by Agarwal “is much easier than handling sutures,” Hovanesian said. “But that is obviously highly surgeon dependent.”

For sutureless techniques, the centration of the entry points is important, according to Hovanesian.

“You want to have the two entry points — the two sclerotomies — exactly diametrically opposite across the pupil for proper centration,” he said. “Being careful when marking for those incisions is key because if the line that bisects the two entry points for the haptics is off from the center of the pupil, the IOL may also be significantly decentered. This usually does not yield a very good functional visual result.”

A second peril is to carefully manipulate the haptics inside the eye.

“Breaking a haptic is a regular occurrence for beginning users of this technique, due to flexing the haptic more than it is designed to be flexed, particularly when bringing the haptic through the incision and handing it off from one instrument to another,” Hovanesian said. “This can cause some haptics to snap.”

If the haptic is significantly shortened through breakage, a new lens is required. “But if only a tiny amount of haptic is broken, the surgeon has to judge whether that lens will have enough haptic length to be secured properly,” Hovanesian said.

Although nearly any three-piece IOL is suitable for sutureless scleral fixation, “you want to try to avoid IOLs that have PMMA haptics because these haptics tend to be more fragile and they will break more easily,” Hovanesian said. “You also want to use an IOL that has the longest overall diameter, including the haptics — 13 mm or larger, if available.”

A lens with a large optic, at least 6 mm in diameter, is desirable as well, “so you have a greater chance of fully centering the lens within the pupil,” Hovanesian said.

Hovanesian said there may be some advantage to using a lens with a rounded optic edge, which intuitively reduces the likelihood of chafing against the iris.

Sutured lens dislocation

Francis W. Price Jr., MD, an OSN Cornea/External Disease Board Member, was co-author of a 2005 study in the Journal of Cataract and Refractive Surgery on late dislocation of scleral-sutured posterior chamber IOLs.

“The study showed that the ciliary body actually caused the polypropylene to degrade,” he said. “You can see cracks in the Prolene and how it became thinner through time.”

Price said that standard 10-0 Prolene sutures in an adult will degrade within 10 years and in children in about 4 years. “Lenses that I implanted 15 years ago with 9-0 Prolene are periodically dislocating,” he said. “Therefore, I think it is really important to periodically revisit some of the old research. We also do not know how long Gore-Tex sutures will last.”

A more recent 2014 article in the same publication, co-authored by Price, shared outcomes of a glued posterior chamber IOL using an intrascleral haptic fixation technique performed at his practice.

“We started out with the STAAR lens with the polyamide haptics, but ended up switching to the Aaren EC-3 IOL (Aaren Scientific) because reports came out that the polyamide haptics can degrade over time,” Price said. “Our whole reason for using a glued IOL is because we do not want the lens to degrade over time.”

However, sutureless IOLs are harder to insert. “Typically, these patients do best by combining the IOL with a pars plana vitrectomy,” Price said. “A lot of anterior segment surgeons are not comfortable performing a PPV, but they really should be.”

Price also said the term “glued IOL” is a misnomer. “The glue has nothing to do with the IOL,” he said. “All you use the glue for is to close the conjunctiva and probably the flaps.”

The off-label tissue glue for sealing “is only there for a maximum of 4 to 5 days,” Price said. “It makes the wound closure easier, but it does not truly have anything to do with holding the lens in place.”

Another advantage of the technique is using essentially 6-0 haptics on the lens implants.

“This is a lot thicker than any of the sutures for fixation,” Price said. “I like that we fix the haptics in the sclera. That means that the lenses are not going to torque and rotate unless there is something pushing the lens inside the eye, which can occur with some scar tissue.”

Price, who has sutured hundreds of lenses to the eye, said sutured IOLs torque more.

Appropriate cases

OSN Cornea/External Disease Board Member Thomas “TJ” John, MD, said eyes with deficient or absent posterior capsular support may be considered for sutureless intrascleral IOL fixation.

“These include subluxated or dislocated IOLs, aphakic eyes requiring a secondary IOL for visual rehabilitation, and eyes with compromised zonular support as in congenital subluxated lens or ectopia lentis where a lensectomy is carried out that is then combined with intrascleral fixation of a posterior chamber IOL,” he said.

John’s surgical technique begins by creating beneath a conjunctival peritomy two partial-thickness, limbus-based, square scleral flaps, measuring about 2.5 mm by 2.5 mm and 180° apart on the same meridian that passes through the central cornea.

“The corneal incision entering the anterior chamber superiorly measures about 3 mm for a foldable IOL and about 6 mm for a non-foldable, rigid optic IOL,” he said.

Then, using a 20-gauge needle, two sclerotomies are made at a distance of about 1 mm to 1.5 mm from the limbus, beneath the scleral flaps. “These sclerotomies are made prior to anterior chamber entry through the corneal wound,” John said.

An anterior chamber maintainer is used during the procedure, and anterior vitrectomy is performed as needed “to remove any vitreous in the anterior chamber that may hamper IOL placement,” John said.

Later, when the two forceps are sequentially moved until the microforceps grab and firmly hold the tip of the trailing haptic, “the leading haptic that is outside the globe is held by an assistant or by silicone tires to prevent accidental pull-through into the interior of the eye,” John said.

John said this sutureless technique can be combined with newer corneal procedures, including endothelial keratoplasty. Iridoplasty can also be combined with the technique to correct any pre-existing iris defects.

Although both foldable and non-foldable IOLs can be used for sutureless scleral fixation of a posterior IOL, “the foldable IOL has the advantage of a smaller corneal wound size and is, therefore, a preferred technique,” John said.

Ideal haptics include those that are made of either PMMA or polyvinylidene fluoride, according to John.

Pros and cons

Christopher J. Rapuano, MD, chief of Cornea Service at Wills Eye Hospital in Philadelphia, said an advantage of sutured scleral fixation over sutureless scleral fixation is “that you are not bringing the haptic out of the eye, which is somewhat of a challenging technique. You also have a slightly bigger hole into the eye because it is bigger than what it takes to just do a suture.”

The disadvantage of the sutured method, however, is relying on a suture to hold the lens implant for potentially decades, according to Rapuano.

“When I started this technique 25 years ago, I used a 10-0 Prolene suture,” he said. “But over decades, sometimes those sutures have broken. As a result, today I use a 9-0 Prolene suture, which is less likely to degrade.”

Some surgeons prefer a Gore-Tex suture, which is much larger. “However, this suture is not indicated for use in the eye,” Rapuano said. “There are also other issues related to using a larger suture. Still, it is certainly a strong and very permanent suture, which is why some doctors like it.”

Rapuano is co-author of a 2016 review of sutureless intrascleral IOL fixation methods published in the Journal of Cataract and Refractive Surgery. “For all of these techniques, you bring the haptic out of the eye,” he said. “It then becomes a matter of how you secure that arm to the outside wall of the eye so it does not slip back in. If the haptic slips back in, the lens kind of falls to the back of the eye.”

These variations on creating the space for the haptic to sit include IOL implantation performed with a needle on a vitreoretinal blade, transconjunctival approaches, IOL implantation with a scleral incision and IOL implantation with a scleral flap using fibrin glue.

“It really boils down to surgeon preference,” Rapuano said. “For instance, if you do a scleral flap, you have to open up the conjunctiva with a bigger incision, which tends to create more scarring and is a slightly longer procedure. For all these sutureless methods, though, you need to secure the haptic without endangering the eye. You do not want there to be an opening from the outside to the inside, where infection can go from the outside of the eye to the inside of the eye.”

Five-year outcomes

Currently, Agarwal and his group in India routinely perform glued intrascleral haptic fixation with the handshake technique. “The results are excellent,” he said.

Their 5-year outcomes, published in 2015 in Ophthalmology, found that of 60 eyes with at least 5 years of follow-up, 35% of eyes had optic tilt detected on OCT and 65% of eyes had no optic tilt. “The tilt was only about 2.5°,” Agarwal said. “Any tilt greater than 5° poses a significant risk.”

To provide fluid in the eye while performing glued IOL procedures, Agarwal designed a trocar anterior chamber maintainer for Mastel Precision Surgical Instruments that acts as an improvised infusion technique. “It is similar to a trocar cannula, but it passes above the iris,” he said. “When you are doing this surgery, you should not use viscoelastic because there is no capsule.”

A three-piece IOL should also always be used with the glued technique. “Any three-piece IOL will work,” Agarwal said. A single-piece foldable IOL is inappropriate because it is too pliable for tucking the haptics into the pocket.

Agarwal also recommended an injector from Abbott Medical Optics because it is highly controllable, especially when the lens is coming out.

However, fixating the haptics into the sclera is also a weakness. “One of the drawbacks is that early on some of these eyes become hypotensive for 2 or 3 days because we make an incision about 1.5 mm peripheral to the limbus in the sclera,” Price said. “This is a big disadvantage.”

Glue is also expensive, costing a few hundred dollars per case, according to Price.

In the U.S., unlike in India, haptics may not be available in as long of lengths as desired, due to the width of the eye. Hence, for patients who rub their eyes or will be implanted with a heavy lens that may cause the lens to dislocate, especially in larger diameter eyes, Price uses a hand-held cautery to create a small bulbous tip on the end of the haptic.

“We do this so that when we tuck the haptic into the sclera, it is more likely that the haptic will scar in place and not come loose,” Price said. Since starting the off-label cauterizing technique about 1 year ago, “I have not had any haptics dislocate.”

Improved distance visual acuity

John cited a 2015 study of sutureless intrascleral IOL fixation from the Journal of Cataract and Refractive Surgery. At a mean follow-up of 9.1 months, there was a statistically significant improvement in corrected distance visual acuity among the 65 eyes of 64 patients, with 89.2% of eyes achieving better or equal vision postoperatively.

For such a procedure, John recommended grabbing the tip of the haptics intraocularly with microforceps, “so that the haptic pull-through transclerally is smooth, without any added tissue damage that has the potential for intraocular bleeding.” He also suggested performing the intrascleral tunnels and the sclerotomies before any decompression of the eye.

In addition, “broad-spectrum antibiotic coverage should be chosen to prevent postoperative infection,” John said.

A potential future modification of sutureless scleral IOL fixation is “fine serrations on the IOL haptics specially designed for this surgical technique,” John said. “This may provide additional stability in anchoring the haptics within the two scleral tunnels.”

“Fortunately, cases where sutureless IOLs are required are fairly few in most of our practices,” Hovanesian said. “We should become familiar with these techniques for appropriate cases or become acquainted with surgeons who do use these techniques if we do not choose to become familiar with them, so that we can refer patients appropriately.”

Hovanesian said there is no question that the sutureless technique has merit. “It will also probably be improved on and will likely grow around the world as a manner of securing IOLs in the absence of capsular support,” Hovanesian said. “But this will not replace normal IOL placement.”

Rapuano said sutureless IOLs have been evolving to smaller incisions and less conjunctival disruption since Agarwal advanced the idea of bringing the haptic out of the eye and securing the haptic to the outside of the eye, without any sutures going inside the eye. “This is all good as long as the IOL is secure,” Rapuano said.

Furthermore, just because a technique works for 5 years, like sutured IOLs, “does not mean it will work for 25 years,” Rapuano said. “Therefore, we need to maintain long-term follow-up to ensure that these sutureless techniques stand the test of time.” – by Bob Kronemyer

• References:
• Agarwal A, et al. J Cataract Refract Surg. 2016;doi:10.1016/j.jcrs.2016.01.015.
• Agarwal A, et al. J Cataract Refract Surg. 2013;doi:10.1016/j.jcrs.2013.01.019.
• Kang JJ, et al. J Cataract Refract Surg. 2015;doi:10.1016/j.jcrs.2015.10.006.
• Karadag R, et al. J Refract Surg. 2016;doi:10.3928/1081597X-20160601-03.
• Kumar DA, et al. Ophthalmology. 2015;doi:10.1016/j.ophtha.2014.07.032.
• McKee Y, et al. J Cataract Refract Surg. 2014;doi:10.1016/j.jcrs.2014.04.027.
• Price MO, et al. J Cataract Refract Surg. 2005;doi:10.1016/j.jcrs.2004.12.060.
• Takayama K, et al. Br J Ophthalmol. 2014;doi:10.1136/bjophthalmol-2014-306579.
• Yamane S, et al. Ophthalmology. 2014;doi:10.1016/j.ophtha.2014.03.019.

• For more information:
• Amar Agarwal, MS, FRCS, FRCOphth, can be reached at Dr. Agarwal’s Eye Hospital, 19 Cathedral Road, Chennai 600086, India; email: dragarwal@vsnl.com.
• John A. Hovanesian, MD, FACS, can be reached at Harvard Eye Associates, 24401 Calle De La Louisa, Suite 300, Laguna Hills, CA 92653; email: drhovanesian@harvardeye.com.
• Thomas “TJ” John, MD, can be reached at Thomas John Vision Institute, 16532 S. Oak Park Ave., Suite 201, Tinley Park, IL 60477; email: tjcornea@gmail.com.
• Francis W. Price Jr., MD, can be reached at Price Vision Group, 9002 N. Meridian St., Suite 100, Indianapolis, IN; email: fprice@pricevisiongroup.net.
• Christopher J. Rapuano, MD, can be reached at 840 Walnut St., Suite 920, Wills Eye Hospital, Philadelphia, PA 19072; email: cjrapuano@willseye.org.

Disclosures: Agarwal reports he is a consultant to Mastel Precision Surgical Instruments. Hovanesian, John, Price and Rapuano report no relevant financial disclosures.

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