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Retinal Physician

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Simplifying Sutureless Scleral-fixated Intraocular Lens Surgery

Incorporate these techniques for enhanced efficiency and efficacy.

By: Christina Y. Weng, MD, MBA
Retinal Physician May 1, 2021 Vol 18, Issue May 2021 Page(s): 24-28

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When there are many ways of doing something, it’s usually a sign that no single “best” way exists. This observation definitely holds true for secondary intraocular lens (IOL) surgery in the absence of capsular support, where surgeons have all learned numerous different approaches — iris-sutured, anterior chamber, scleral-sutured, scleral-tunneled — for which there are dozens of subtle variations in technique. Although each of these approaches is befitting for different circumstances, over the past 3 years, my preferred method has been the sutureless flanged scleral-fixation technique, sometimes referred to as a “modified Yamane” named after Japanese surgeon Shin Yamane, MD, PhD.1 The concept behind his original technique entails externalizing the haptics of a 3-piece IOL via thin-walled needles through transconjunctival sclerotomies 180° apart, and then melting a flange at the haptic tips to stabilize the haptics in the scleral wall without sutures or glue. Based on the prior work of many, one modification involves externalizing the haptics through trocar cannulas instead of needles.2-6 Although there are slight differences among techniques, this article will describe my personal technique and address some of its nuances.

PREOPERATIVE CONSIDERATIONS

Determining a Surgical Plan

As with any surgery, preoperative planning is perhaps the most critical step. After verifying that the patient has healthy, mobile conjunctiva, you will face 2 main scenarios: a rescue IOL or implantation of a new IOL. For a rescue IOL, the patient already has an appropriate 3-piece IOL that is either subluxated or dislocated and can be used for this procedure. In this case, ensure that the IOL has not been damaged and will permit flanging; obtaining prior records may be helpful. If the IOL was previously in the capsular bag, counsel the patient regarding a possible subsequent refractive shift because the IOL often effectively sits more anteriorly. For implantation of a new IOL, the patient may require concurrent explantation of an existing IOL, lens fragments, or accessories like a capsular tension ring. In this situation, selection of a new IOL will be necessary.

Choosing an IOL and IOL Power

Although many IOLs might work for scleral-fixation, I have used these with success: MA60AC (Alcon), ZA9003 (J&J), CT Lucia 602 (Carl Zeiss Meditec); the latter has the most malleable haptics. Of note, these (and most IOLs in the United States) are not approved for sulcus placement. The most accurate IOL calculation formula for this technique remains unclear,7 but similar to my anterior segment colleagues, I typically use either the IOL power that corresponds to a plano refraction in the capsular bag (if externalizing 2.5 mm posterior to limbus) or subtract 0.5D from that (if 2 mm posterior to limbus).

Anesthesia

Whether using a peribulbar or retrobulbar block, avoid creating bullous conjunctiva with the local anesthetic. If the conjunctiva balloons despite best efforts, it can help to proceed with localized peritomies in the externalization loci, because precise cannula placement is critical in this procedure.

INTRAOPERATIVE PEARLS

Stake Out Your Territory

If an IOL, lens fragments, or accessories need to be removed, I prefer to use a 23-gauge and 27-gauge platform (23 gauge refers to the cannulas used for the vitrectomy portion, hereafter referred to as “ports,” and 27 gauge refers to the cannulas used to externalize the IOL haptics, hereafter referred to as “cannulas”). Externalizing through 25-gauge cannulas also works if you make the haptic bulbs slightly larger. A 3-port 27-gauge platform using the cannulas to perform the vitrectomy as well as externalize the haptics has also been described.8 In this scenario, minimize cannula manipulation during the vitrectomy portion so as not to inadvertently enlarge the scleral tunnels.

Positioning of the externalization cannula is critical to avoid IOL tilt and decentration. Start by using a corneal marker centered on a dry cornea using the limbus — not the pupil — as a base (Figure 1A). I externalize at 1 o’clock and 7 o’clock in right eyes and at 11 o’clock and 5 o’clock in left eyes, accounting for the nasal bridge. Make your marks exactly 180° apart and then mark 2 mm to 2.5 mm posteriorly to the limbus, avoiding areas of conjunctival fibrosis, blebs, or tube shunts. When placing the externalization cannulas, bevel at 30° to 45° following an inverted “S” and then enter the vitreous cavity perpendicularly to the ocular surface to complete the biplanar scleral tunnel. It is critical that the bevel angle, tunnel length, and point of entry be exactly mirrored on the other side. Symmetrical “puckering” of the cannulas often indicates good placement (Figure 1B). After these cannulas are placed, the other ports can be inserted in usual fashion. For left eyes, place the infusion line inferonasally to keep it out of the way.

Figure 1. Use a corneal marker to designate the meridians for externalization cannula placement precisely 180° apart (A). Center the marker around the limbus, not the pupil, which can be irregular as seen here. 23-gauge and 27-gauge set-up for a patient with retained lens fragments and posteriorly dislocated IOL complex (B). The slight sideways “puckering” of the 27-gauge cannulas in an inverse “S” shape often indicates good tunneling. Note the inferonasal placement of the infusion line in this left eye.
Figure 1. Use a corneal marker to designate the meridians for externalization cannula placement precisely 180° apart (A). Center the marker around the limbus, not the pupil, which can be irregular as seen here. 23-gauge and 27-gauge set-up for a patient with retained lens fragments and posteriorly dislocated IOL complex (B). The slight sideways “puckering” of the 27-gauge cannulas in an inverse “S” shape often indicates good tunneling. Note the inferonasal placement of the infusion line in this left eye.

Step-by-Step IOL Placement

Regardless of whether you are rescuing or implanting a new IOL, step 1 will be to perform a complete vitrectomy. Ignore whatever is in the vitreous cavity until the vitrectomy is done. It is particularly important to perform a close shave of the vitreous base because there will be quite a bit of manipulation near that area where the IOL can exert traction on residual vitreous. Complete your 360° scleral-depressed examination before you start working on the IOL.

Scenario: Explantation of Old IOL and Fixation of New IOL

Once the vitrectomy is complete, the dislocated IOL should first be explanted. As a right-handed surgeon, I make a corneal paracentesis at 2 o’clock and a triplanar corneal wound (use a 2.75-mm keratome and slightly extend) at 11 o’clock. With the light pipe through the right-hand port and cutter through the left-hand port, elevate the IOL to the sulcus using vacuum-only on the maximum setting. Flip out the indirect viewing system and swap your light pipe for retina forceps (I prefer Alcon’s MaxGrip forceps). Enter the corneal wound and mobilize the IOL into the anterior chamber. Use the forceps with your left hand through the paracentesis to grasp the optic, and use IOL-cutting scissors with the right hand through the corneal wound (Figure 2A). Cut along the axis of the haptics just past the midway point and then use the “Pac-Man” technique to rotationally explant the IOL (Figure 2B).

Figure 2. Grasp the optic with retina forceps through the paracentesis while using intraocular lens cutting scissors through the corneal wound to cut past the midway point along the axis of the haptics (A). Rotationally explant the intraocular lens through an approximately 3-mm corneal wound via “Pac-Man” technique (B).
Figure 2. Grasp the optic with retina forceps through the paracentesis while using intraocular lens cutting scissors through the corneal wound to cut past the midway point along the axis of the haptics (A). Rotationally explant the intraocular lens through an approximately 3-mm corneal wound via “Pac-Man” technique (B).

Next, insert or inject the new IOL into the anterior chamber with the (inferior) leading haptic below the iris and the (superior) trailing haptic residing partially outside the corneal wound. Use forceps to manipulate the trailing haptic to optimize the view of the leading haptic. Insert retina forceps through the inferior cannula to grasp the haptic tip; securing the very distal end is critical to prevent haptic breakage. If you have trouble grabbing the tip given the position of the IOL, grab anywhere along the haptic itself. Then, use another pair of retina forceps through the right-hand vitrectomy port and use a hand-to-hand maneuver to grasp the haptic so your left-hand forceps can reposition to the very tip of the haptic (Figure 3A-3D).

Figure 3. Inject the new intraocular lens with the leading haptic below the iris and the trailing haptic residing outside the corneal wound (A). Manipulate the external trailing haptic with forceps to bring the leading haptic into view so that it can be grasped anywhere with retina forceps (B). Use a hand-to-hand technique to then grasp the haptic with another pair of retina forceps through the vitrectomy port (C). This will allow the externalization forceps to reposition to the haptic tip and externalize the inferior haptic (D). The same hand-to-hand technique is then used for the superior haptic by passing the trailing haptic to forceps through the vitrectomy port (E). While stabilizing the haptic with one hand, the externalizing retina forceps in the other hand can grab the distal tip of the superior haptic and externalize it (F).
Figure 3. Inject the new intraocular lens with the leading haptic below the iris and the trailing haptic residing outside the corneal wound (A). Manipulate the external trailing haptic with forceps to bring the leading haptic into view so that it can be grasped anywhere with retina forceps (B). Use a hand-to-hand technique to then grasp the haptic with another pair of retina forceps through the vitrectomy port (C). This will allow the externalization forceps to reposition to the haptic tip and externalize the inferior haptic (D). The same hand-to-hand technique is then used for the superior haptic by passing the trailing haptic to forceps through the vitrectomy port (E). While stabilizing the haptic with one hand, the externalizing retina forceps in the other hand can grab the distal tip of the superior haptic and externalize it (F).

Once you have a good grasp of the haptic tip, pull out until you feel slight resistance from the internal end of the cannula. Stop pulling and use 0.3-mm forceps with your right hand to elevate the cannula up along the shaft of the retina forceps. Externalize with your left hand while pinching firmly. Next, use angled tying forceps through the corneal wound to pass the trailing haptic hand-to-hand to retina forceps placed through the left-hand vitrectomy port. Again, grab anywhere along the haptic with your left hand. Then take the retina forceps with your right hand through the superior externalization cannula, grab the distal haptic tip, and externalize gently (Figure 3E-3F).

POINTERS

  • Do not grab the haptics too forcefully!
  • Watch the inferior haptic to make sure it is not inadvertently pulled back into the vitreous cavity. If you have an assistant, they can use tying forceps to lightly hold it in place while you are externalizing the superior haptic. 
  • Never use toothed forceps to handle the IOL optic or haptics.

Scenario: Rescue IOL

If rescuing an IOL, you can also mobilize it to the anterior chamber and follow the steps above. However, it is often easier to keep the IOL in the posterior segment. Simply insert retina forceps through either the superior or inferior cannula, grab the haptic tip, and follow the same aforementioned externalization process (Figure 4A). Then, use the retina forceps through the contralateral cannula, grab the haptic tip, and again externalize (Figure 4B and 4C). This method works best utilizing the indirect visualization system, so you will need to flip it in and out as you move between grabbing the haptic and externalizing it where direct visualization is necessary. Some have used chandelier endoillumination to facilitate a bimanual approach, but I have not found this necessary.

Figure 4. When rescuing an intraocular lens, use retina forceps through the cannula to grasp the haptic tip and externalize (can start either inferiorly or superiorly) (A). With the superior haptic externalized here, use the indirect viewing system to then grasp the inferior haptic tip (B). Pull out with the retina forceps until resistance is met at the internal mouth of the cannula and then elevate the cannula along the forceps shaft as shown here before externalizing (C).
Figure 4. When rescuing an intraocular lens, use retina forceps through the cannula to grasp the haptic tip and externalize (can start either inferiorly or superiorly) (A). With the superior haptic externalized here, use the indirect viewing system to then grasp the inferior haptic tip (B). Pull out with the retina forceps until resistance is met at the internal mouth of the cannula and then elevate the cannula along the forceps shaft as shown here before externalizing (C).

POINTERS

  • Make sure the IOL is in the inverse “S” position while resting on the retinal surface before you proceed. If it is not, use the cutter or retina forceps to flip it over.
  • If grabbing the haptic tip proves to be difficult, you can grasp anywhere along the haptic, elevate the IOL to the sulcus level, and use a hand-to-hand maneuver to adjust the positioning of the externalizing forceps while assisting with other retina forceps through the vitrectomy port.

FORMING THE FLANGES

Gently grasp the haptic tip with tying forceps and hold a low-temperature cautery nearby to create a flange. The cautery should not make direct contact with the haptic. Do not grab too close to the tip or there will not be sufficient material to form the bulbed end.

POINTERS

  • When grasping the haptic tip, elevate it slightly upwards off the wet ocular surface. Soak up surrounding fluid with a Weck-Cel sponge (BVI) to help the haptic form as desired (Figure 5A and 5B).
  • Minor centration adjustments can be made while forming the flanges (Figure 6). Adjust the haptics to see how the IOL optic is best centered; trimming one haptic before flanging it can sometimes be beneficial, but do not shorten it so much that the haptic is on tension.

 

Figure 5. Slightly elevating the haptic and drying the surrounding field with a sponge enables a controlled cautery melt (A). Flanged haptic of a CT Lucia 602 IOL (Carl Zeiss Meditec) (B). Use tying forceps to tuck the haptic ends into the scleral tunnel covered by conjunctiva (C).
Figure 5. Slightly elevating the haptic and drying the surrounding field with a sponge enables a controlled cautery melt (A). Flanged haptic of a CT Lucia 602 IOL (Carl Zeiss Meditec) (B). Use tying forceps to tuck the haptic ends into the scleral tunnel covered by conjunctiva (C).
Figure 6. Well-centered IOL is shown as the superior haptic bulb is formed. The haptics can be slightly shortened to make minor centration adjustments if necessary.
Figure 6. Well-centered IOL is shown as the superior haptic bulb is formed. The haptics can be slightly shortened to make minor centration adjustments if necessary.

Once the flanges have been created, use tying forceps to gently nudge them until they reside just beneath the external opening of the scleral tunnel (Figure 5C). If insufficiently buried, the patient may experience a foreign body sensation, or worse, the haptics may erode through the conjunctiva. Opening the conjunctiva in this procedure is generally not necessary, but do not hesitate to create a small localized peritomy if needed for visualization. As with all my combined cases, I like to suture the 3 vitrectomy port sclerotomies to prevent hypotony. Lastly, I will mention that some place a prophylactic peripheral iridotomy to prevent reverse pupillary block, which has been reported postoperatively.9,10

POSTOPERATIVE TIPS

I inject subconjunctival antibiotic and steroid at case end and prescribe my usual postoperative drop regimen. Most patients enjoy improved vision by the first postoperative day or week, often depending on the extent of corneal edema. I typically defer dilation for 1 week as optic pupillary capture can occur while the IOL is still settling into position.

CONCLUSION

Long-term stability and visual outcomes associated with this relatively new technique will be learned over time, but large case series have reported promising results thus far.11 I have found this scleral-fixation approach to be effective and efficient, especially since incorporating the hand-to-hand maneuver described above, which greatly simplified this procedure. Patients seem to have a more rapid recovery because this surgery can be done expeditiously without much manipulation of the eye. Another advantage is avoidance of sutures, which can erode over time, and other risks inherent to iris-fixated and anterior chamber IOLs. RP

Christina Y. Weng, MD, MBA, is an associate professor of ophthalmology, the fellowship program director for vitreoretinal diseases and surgery at Baylor College of Medicine, and the director of medical student clinical electives at Ben Taub General Hospital in Houston, Texas. Dr. Weng reports consultancy to Allergan/AbbVie, Alcon, Alimera Sciences, Novartis, Regeneron, Regenxbio, Genentech, and DORC. Reach her at christina.weng@bcm.edu. Editor’s note: This article is discussed in an episode of The Retina Podcast. Listen at www.retinapodcast.com .

REFERENCES

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  7. Lee R, Govindaraju V, Farley ND, et al. Refractive outcomes after sutureless intrascleral fixation of intraocular lens with pars plana vitrectomy. Retina. 2021;41(4):822-826. doi:10.1097/IAE.0000000000002916
  8. Thanos A, Lau-Sickon LK, Wolfe JD, Hassan TS. Three port sutureless posterior chamber intraocular lens intrascleral fixation: a novel approach. Retina. 2019;39 Suppl 1:16-20. doi:10.1097/IAE.0000000000001925
  9. Singh H, Modabber M, Safran SG, Ahmed II. Laser iridotomy to treat uveitis-glaucoma-hyphema syndrome secondary to reverse pupillary block in sulcus-placed intraocular lenses: Case series. J Cataract Refract Surg. 2015;41(10):2215-2223. doi:10.1016/j.jcrs.2015.10.057
  10. Bharathi M, Balakrishnan D, Senthil S. “Pseudophakic reverse pupillary block” following Yamane technique scleral-fixated intraocular lens. J Glaucoma. 2020;29(7):e68-e70. doi:10.1097/IJG.0000000000001538
  11. Abbey AM. Sutureless intrascleral fixation of intraocular lenses: clinical outcomes and comparative effectiveness of haptic flanging in a series of 488 eyes. Paper presented at: 2020 American Society of Retina Specialists Annual Meeting (virtual).

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