IOLs that dislocate postoperatively may be repositioned rather than removed. A surgeon describes techniques for rescuing a dislocated sulcus-fixated IOL and a subluxated in-the-bag IOL.
New Orleans-IOLs that decenter or dislocate postoperatively often can be rescued rather than sacrificed, said Roger F. Steinert, MD, at the annual meeting of the American Academy of Ophthalmology.
Speaking during a symposium dedicated to discussions of challenging cataract surgery cases, Dr. Steinert illustrated his point by presenting various scenarios of IOL dislocation/decentration and their management.
"Anterior segment surgeons can safely perform the pars plana vitrectomy by following a few basic guidelines that include starting 3.0-mm back from the limbus and bringing the infusion in through the paracentesis," he said.
In addition, because it is necessary to capture the optic in the pupil in these cases, standard pupil dilation techniques should not be used for the vitrectomy. If the pupil needs to be enlarged, a small amount of phenylephrine can be used, because it will not interfere with pharmacologic pupil constriction at the end of the case. Usually, the retrobulbar block will induce enough dilation initially to manipulate the IOL. Subsequently, acetylcholine chloride (Miochol-E, Novartis Ophthalmics) or carbachol can readily constrict the pupil.
Once the vitrectomy is completed, the implant is brought up through the pupil and the optic captured while the haptics are left in the sulcus. Visualization of the haptics can be facilitated by injecting a high-molecular-weight viscoelastic, usually 1.4% sodium hyaluronate (Healon GV, Advanced Medical Optics). The viscoelastic will push the peripheral iris posteriorly, but if that is not sufficient to show the position of the haptic, the optic can be levitated slightly by placing an instrument, such as the Barraquer sweep, under the optic.
The haptics then are sutured to the iris. Dr. Steinert emphasized that taking small bites and placing them in the periphery are the keys to achieving a regular, round pupil. A 10-0 polypropylene suture (Prolene, Ethicon) can be used for the suturing because there are no chafing concerns, he noted.
The knot can be withdrawn peripherally through a paracentesis opening and tied. Dr. Steinert, however, stated that he prefers the slipknot technique as described originally by Stephen Siepser, MD, and using the modification introduced by Robert Osher, MD, to ensure locking.
Late subluxation of an in-the-bag IOL
The clinical situation of late subluxation of an in-the-bag IOL can arise in eyes with zonular damage antecedent to cataract surgery or induced by postoperative trauma. It is most commonly seen in eyes with pseudoexfoliation as a result of progressive zonular loss, however.
Explantation would involve a major procedure involving vitrectomy. McCannel suturing, as described above, is not an option because the haptics are encased in the bag. The surgeon can successfully reposition and anchor the IOL in a straightforward scleral fixation technique, however.
The procedure requires a slightly curved, long, sharp needle that can be created by modifying either of two proprietary needles (CTC-6L or STC-6, Ethicon). The former is too curved and the latter is too straight, Dr. Steinert said. "A modification to either is needed to create a gentle curve that will be just right," he added.
After taking down conjunctiva at the location where the haptic is thought to be most peripheral, entry with the needle is made over the sulcus, about 1 mm behind the limbus, to expose the peripheral capsule and haptic. The needle is advanced anteriorly, going up through the peripheral bag between the haptic and the optic.
"A gently curved configuration is needed because the needle has to come in front of the optic," said Dr. Steinert.
Then, the needle is docked in the end of a blunt-tip cannula so that it can be delivered out through a paracentesis located between 4 and 6 o'clock. As the needle emerges, it is grasped with a needle holder and then flipped around, reinserted, and advanced over the capsular bag, exiting through the sulcus. Viscoelastic is used to help to push the capsular bag/implant complex posteriorly.