IOL scaffold prevents fragment drop in posterior capsular rupture

The technique also compartmentalizes the eye, thus preventing hydration of the vitreous that can result in more vitreous prolapse.

Thomas John

Phacoemulsification has come a long way in both technological advances and newer surgical techniques that increase efficiency, cut down total surgical time and improve the visual outcome for patients.

Unfortunately, one factor cannot be eliminated from the surgical scene — potential surgical complications. One such complication that the ophthalmic surgeon dreads most is an accidental tear in the posterior capsule during phacoemulsification of a cataractous nucleus. Depending on the timing of the posterior capsular tear, the degree of difficulty can vary from relatively easy to handle to an extremely difficult, complex situation that the surgeon has to recover for a relatively good postoperative outcome. Associated with capsular tear is the inherent concern of dropping the remaining lens material into the vitreous cavity and possibly on to the retina. It would be nice to have a surgical technique that can help insulate the surgeon from dropping the lens material into the vitreous.

In this column, Drs. Agarwal and Jacob describe a new technique that utilizes a pre-placed IOL within the anterior chamber as a scaffold to prevent dropping the lens material posteriorly during phacoemulsification in the presence of a posterior capsular rent.

Thomas John, MD
OSN Surgical Maneuvers Editor

by Amar Agarwal, MS, FRCS, FRCOphth, and Soosan Jacob, MS, FRCS, DNB

Amar Agarwal

Soosan Jacob

Posterior capsular rupture is one of the major problems encountered by any cataract surgeon and is an especially daunting task when it occurs in the presence of retained nucleus, epinucleus and cortex. The aim is to remove all these components completely while causing the least amount of vitreous traction and without allowing any fragment drop into the posterior segment. At the same time, it is ideal to be able to complete the entire surgery through small incisions, thus negating complications associated with large incisions, such as wound leak, shallow anterior chamber, endophthalmitis and postoperative astigmatism.

The normal trend is to bring the nuclear fragments out of the bag into the anterior chamber and to keep them supported temporarily on the iris until they are emulsified in the anterior chamber or, in case of the entire nucleus, to bring the nucleus out through a corneoscleral section. One of the problems in emulsifying nucleus in the presence of a posterior capsular rupture is that fragments can fall posteriorly through the posterior capsular rupture into the vitreous cavity, necessitating a pars plana vitrectomy for their removal. Various techniques and materials have been proposed to prevent this complication from happening, including the use of a Sheets glide, a Hema contact lens lifeboat by Dr. Keiki Mehta, and phacoemulsification after injecting perfluorocarbon liquid in collaboration with a vitreoretinal surgeon.

While it is still advisable to bring the nucleus out in toto by enlarging the incision in case of posterior capsular rupture with the entire hard nucleus in situ or an entire hard nucleus that has been dropped into the vitreous, we describe a new technique for tackling lens fragments up to hard hemi-nuclei and soft, clear whole nuclei. This was devised by Dr. Agarwal and involves using an IOL as a scaffold to prevent nuclear fragments from falling down into the vitreous cavity.

Anterior vitrectomy is performed in case of vitreous loss, and the nucleus is brought on to the iris surface (Figures 1a and 2). A dispersive viscoelastic is injected into the anterior chamber to protect the cornea. Anterior vitrectomy is performed, and the epinucleus and cortex are removed, alternating between cutting and aspiration modes of the vitrector. A foldable three-piece IOL is then injected into the anterior chamber, taking care to allow the IOL to gently unfold in the anterior chamber. Wound-assisted implantation should not be performed in order to prevent the IOL from entering in an uncontrolled manner and accidentally falling into the vitreous cavity.

Figure 1. The nuclear fragment is brought above the iris (a). The IOL is injected so as to insert the leading haptic above the iris and the optic covering the pupillary area (b). The nucleus is emulsified using the phaco probe while using the IOL as a scaffold to prevent the lens pieces from falling into the vitreous cavity (c). The IOL is dialed into the sulcus (d). Images: Agarwal A, Jacob S

Figure 2. Posterior capsular rent with retained nucleus (a). The nucleus is brought out of the bag into the anterior chamber. The IOL is then injected into the anterior chamber with the leading haptic over the iris and under the nuclear fragments (b). The trailing haptic is left outside the wound (c). The nucleus is emulsified over the surface of the IOL using the IOL as a scaffold to prevent nuclear fragments from falling down into the vitreous cavity (d).

The leading haptic is maneuvered over the iris and the second haptic is left trailing outside the wound (Figures 1b and 2). If required, the wound may be enlarged minimally for this step. The rest of the procedure can be carried out with the second haptic left trailing outside the wound, especially in case of atonic pupils. But if the pupil has a good tone, is not floppy, and is between 5 mm to 6 mm in size, the trailing haptic can also be gently positioned over the iris so that the entire IOL now lies on the iris surface and the optic sits over the pupil.

Once the IOL is stable in this position, the nuclear fragments are emulsified in the anterior chamber (Figures 1c and 2). If the trailing haptic has been left outside the wound, the optic-haptic junction on the trailing side is then maneuvered using a dialer in the nondominant hand so that the IOL blocks the pupil. Gas-forced infusion in the form of an external air pump or an inbuilt air pump, as present in many newer phaco machines, allows the anterior chamber depth to be well maintained. The nucleus is then emulsified using low vacuum settings. The optic of the IOL acts as a scaffold and prevents nuclear fragments from dropping into the vitreous cavity. It also prevents vitreous from prolapsing into the anterior chamber and getting aspirated into the phaco probe. After nucleus removal, the completeness of anterior vitrectomy and cortex removal and the capsular support are again assessed. If adequate capsular support exists, the IOL is dialed into the sulcus (Figures 1d and 2). If not, it is glued into place using the glued IOL technique.

This technique not only prevents dropping nuclear fragments into the vitreous, but also compartmentalizes the eye, thus preventing hydration of the vitreous that can result in more vitreous prolapse. There is also no need for extending the phaco incisions, neither any need to insert a temporary device or substance for nuclear support that then needs to be removed, causing additional trauma. The insertion of an IOL that is going to eventually be implanted is merely pre-placed by this technique. If both haptics of the IOL are over the iris, more space is created in the anterior chamber for easy emulsification of the nuclear pieces. If the second haptic is left trailing out, the dialer held by the nondominant hand manipulates the optic to lie low flush against the pupil as well as centered over the pupil to create adequate space in the anterior chamber, as well as to avoid nuclear fragment drop.

References:

• Chan E, Mahroo OA, Spalton DJ. Complications of cataract surgery. Clin Exp Optom. 2010;93(6):379-389.
• Ermiss SS, Oztürk F, Inan UU: Comparing the efficacy and safety of phacoemulsification in white mature and other types of senile cataracts. Br J Ophthalmol. 2003;87(11):1356-1359.
• Shah VA, Gupta SK, Chalam KV. Management of vitreous loss during cataract surgery under topical anesthesia with transconjunctival vitrectomy system. Eur J Ophthalmol. 2003;13(8):693-696.
• Wilczynski M, Wilczynska O, Synder A, Omulecki W. Incidence and functional outcome of phacoemulsification complicated by posterior capsular rupture. Klin Oczna. 2009;111(1-3):26-29.

• Amar Agarwal, MS, FRCS, FRCOphth, and Soosan Jacob, MS, FRCS, DNB, can be reached at Dr. Agarwal’s Eye Hospital, 19 Cathedral Road, Chennai, India 600086; 91-44-28116233; fax: 91-44-28115871; email: dragarwal@vsnl.com, dr_soosanj@hotmail.com.
• Edited by Thomas John, MD, clinical associate professor at Loyola University at Chicago and in private practice in Oak Brook, Tinley Park and Oak Lawn, Ill. He can be reached at 708-429-2223; fax: 708-429-2226; email: tjcornea@gmail.com.
• Disclosure: Drs. John, Agarwal and Jacob have no relevant financial disclosures.