IOL placement with a posterior capsular tear

Loss of the posterior capsule and its potential support for the IOL is one of the most difficult challenges we face as cataract surgeons. Efficient management of this complication is important for the long term health of the operative eye. Here I will present a few suggestions on IOL placement in this situation and a few videos that may be helpful for the beginning surgeon.

The initial challenge is to adequately remove the residual lens material and vitreous while leaving as much capsule as possible to assist in supporting the IOL. It is very important that the vitreous has been completely removed from that the anterior segment as outlined in other sections of this blog. Then you must face the often tough decision of whether to place the IOL in the bag, sulcus, a combination of the bag and sulcus, or in the anterior chamber. You should also be ready to place sutures to secure the IOL to the iris if the sulcus placement is not stable.

Bag placement. Sometimes even with a posterior capsular tear an IOL can be gently placed in the bag most commonly when the tear is round or converted to a round tear. It is very important that the posterior capsular tear is stable as the force of placing the IOL can extend the tear further, releasing more vitreous, and could lead to placement of the IOL onto the retina. Here is a video of a planned posterior capsular rhexis and the gentle placement of a single piece acrylic into the bag.

Sulcus Placement. Usually when you have a posterior capsular tear the IOL is placed in the sulcus. The most important thing is to have a proper IOL for the sulcus ready to go in your OR at all times. The best IOL for the sulcus has a large optic that allows for mild decentration and a better view of the retina. The best IOL for the sulcus has long haptics that will center the IOL even in large eyes. The best IOL for the sulcus has smooth thin haptics to reduce chaffing of the posterior leaf of the iris^{3, 4}. I prefer acrylic over silicon IOLs for sulcus implantation as patients with capsule trauma are at increased risk for retinal detachment and the possible use of silicon oil. I like the Alcon MA50 3 piece IOL as it has wide haptics, a large yet injectable 6.5 mm optic and it is acrylic. Others advocate for the large Starr silicon IOL (AQ2010V) as they feel that the larger haptics and rounded optic edge out weigh the advantage of the acrylic material. Please remember to always use a large 3 piece IOL for this job and not a single piece acrylic (SPA). SPA IOLs are not designed for the sulcus and the large square edge haptic can cause uveitis, hyphema, vitreous hemorrhage, and glaucoma.

The second most important thing is to place the IOL with both haptics in the sulcus. If you place one haptic in the sulcus and the other in the bag the IOL will be unstable and often decentered. One reason that it is hard to get both haptics in the sulcus is that the most common area of damage to the capsule is directly across from the wound. This area is vulnerable to radial tears as OVD is often running low as the capsulorhexis passes this point and this area is vulnerable as the phaco tip and chopper are active in this region. Unfortunately this is the same area where the leading haptic naturally flows during IOL insertion. If the capsule is damaged in this area then the sulcus is poorly defined and the leading haptic can end up posterior to the anterior capsule rather than in the sulcus as intended. Defining the sulcus with a viscous dispersive viscoelastic (e.g. Viscoat) will greatly ease placement of the haptics.

Combination of Sulcus and Bag. . When you have a posterior capsular tear with a nicely centered and intact anterior capsulotomy you have more options. One of the nicest options is to first place the IOL in the sulcus and then prolapse the optic posteriorly capturing it by the anterior capsule while leaving the haptics securely in the sulcus [1]. This technique allows coverage of most of the IOL edge with capsule, allows the centered anterior capsulotomy to keep the IOL centered, and still allows suture fixation of the sulcus based haptics to the iris if needed. Here is a nice video showing this technique:

Rarely, you will encounter the situation with a late tear of the posterior capsule when a SPA IOL is already placed in the bag. In this situation you should strongly consider simply exchanging the SPA IOL for a 3 piece IOL designed for the sulcus. However another option with a perfectly centered intact anterior capsulotomy is to anteriorly displace the optic from the bag such that the optic is captured by the anterior capsulotomy and the haptics remain in the bag which protects the iris from the square edge. Here is a video showing this technique which will rarely present.

AC IOL. When the IOL cannot be adequately supported by the sulcus, surgeons have several options: place an AC IOL, suture the IOL to the iris, or suture the IOL to the sclera. Another option which is often not available in an emergent setting is to use an iris clip IOL such as the Artisan but this IOL has not been approved for this indication by the US FDA [2]. None of these approaches is clearly superior. Wagoner as part of an American Academy of Ophthalmology study reported that there is no significant difference in results when comparing AC IOLs, iris sutured IOLs, or scleral sutured IOLs when capsular support is insufficient [3]. As such practical concerns such as availability of devices, ease of the procedure, and surgeon preference drive this decision. I have outlined the placement of AC IOL in this blog.

Iris sutured IOLs offer some practical advantages over scleral sutured IOLs in the emergent situation of a posterior capsular tear (I almost never place scleral sutured IOLs in this situation). One advantage is that you can place a 3 piece IOL in the sulcus and then asses if the residual capsule alone will support the IOL. If the 3 piece IOL does not center or seems unstable, the IOL can be readily sutured to the iris without changing the IOL or explanting haptics to tie scleral based suture. The IOL optic is moved anteriorly and captured by the pupil with the addition of acetylcholine (Miochol-E Novartis). The haptics are sutured to the peripheral iris using modifications of McCannel’s technique [4] with either an external knot [5,6] or with a sliding internal knot as described by Chang [7]. Typically 10-O prolene suture is used with a long curved needle such as a CTC-6 needle (Ethicon # 9090G-SD) to secure the haptics to the iris. Here is a video where the zonlues were severly damaged and after placing the IOL in the sulcus the IOL was sutured to the iris.

Suturing IOLs to the sclera especially in an emergent setting is probably the most difficult option. Techniques to suture IOLs to the sclera often employ special IOLs with haptic eyelets [8], require more robust suture material such as 9-O prolene, and may require a scleral flap or tutoplast to cover the external suture material [9]. The routine use of 10-O prolene suture material has been reconsidered as many of these sutures eroded and broke over time. Additionally, suturing an IOL to the sclera after placing the IOL is difficult as the haptics would have to be externalized to set the suture which is more complicated than the iris suture technique.

In summary if the sulcus seems sufficient to support the IOL then the surgeon should place a large 3 piece IOL in the cililary sulcus. If after placement in the sulcus, the IOL does not seem stable, then the surgeon can supplement the capsule support with iris fixation sutures and the long term results seem excellent [10]. If it is clear that the sulcus will not support an IOL, then i tend to place an AC IOL as it is a simpler procedure and offers at least similar results to scleral or iris sutured IOLs [3].

References

1. Gimbel HV, Sun R, Ferensowicz M, Anderson Penno E, Kama, Intraoperative management of posterior capsule tears in phacoemulsification and intraocular lens implantation, Ophthalmology, 2001 Dec;108(12):2186-9; discussion 2190-2.
2. Oetting TA, Newsom T, Bilateral Artisan lens for aphakia and megalocornea: Long-term follow-up, J Cataract Refract Surg. 2006 Mar;32(3):526-8.
3. Wagoner MD, Cox TA, Ariyasu RG, Jacobs DS, Karp CL; Intraocular lens implantation in the absence of capsular support: a report by the American Academy of Ophthalmology, Ophthalmology. 2003 Apr;110(4):840-59.
4. McCannel MA. A retrievable suture idea for anterior uveal problems. Ophthalmic Surg 1976; 7(2):98–103.
5. Stutzman RD, Stark WJ, Surgical technique for suture fixation of an acrylic intraocular lens in the absence of capsule support J Cataract Refract Surg. 2003 Sep;29(9):1658-62.
6. Condon GP., Simplified small-incision peripheral iris fixation of an AcrySof intraocular lens in the absence of capsule support, J Cataract Refract Surg. 2003 Sep;29(9):1663
7. Chang DF, Siepser slipknot for McCannel iris-suture fixation of subluxated intraocular lenses, J Cataract Refract Surg. 2004 Jun;30(6):1170-6.
8. Buckley EG, Safety of transscleral-sutured intraocular lenses in children, J AAPOS. 2008 Oct;12(5):431-9. Epub 2008 Aug 15
9. Oetting TA, Johnson AT, Tisseel and Tutoplast cover, J Cataract Refract Surg. 2007 Dec;33(12):2153, Comment: J Cataract Refract Surg. 2008 Jun;34(6):881-2; author reply 882.
10. Condon GP, Masket S, Kranemann C, Crandall AS, Ahmed II, Small-incision iris fixation of foldable intraocular lenses in the absence of capsule support, Ophthalmology, 2007 Jul;114(7):1311-8.