Residual capsule important in managing dislocated IOLs

Many dislocated lenses can be repositioned using residual capsular support.

DALLAS — Peripheral residual posterior capsule can be an important structure to use in repositioning a dislocated IOL, according to a presentation here. Even though each dislocated IOL must be managed its own way, the residual capsule can often be used for support, said Gregg Kokame, MD, at the annual meeting of the American Academy of Ophthalmology (AAO).

In a retrospective study, Dr. Kokame said he found that in 58% of IOL repositioning cases the residual capsule was used to support at least one haptic. “Because of this, it is important to preserve residual peripheral capsule during complicated cataract surgery,” he said.

Different techniques

--- Dislocation of posterior chamber IOL within an intact capsular bag.

According to Dr. Kokame, management of dislocated IOLs can use either an anterior or posterior segment approach.

“Anterior approaches can be performed when the IOL is subluxated but stable within the anterior segment. Pars plana microsurgical management is used when the distal should be dislocated, the IOL is unstable or posteriorly dislocated or there are associated vitreoretinal problems,” he said.

In his study, Dr. Kokame reviewed 41 cases of dislocated IOL management using the pars plana approach in 34 eyes of 34 patients; seven cases were recurrent dislocations. The age of the patients ranged from 22 years to 92 years. The mean age was 68 years. All the patients in the study had symptoms including blurred vision, floaters or pain. Best corrected visual acuity was 20/40 or better in 5 eyes, 20/50 to 20/100 in 9 eyes and 20/200 or worse in the remaining 20 eyes.

Of the 34 lenses, 31 were posterior chamber IOLs and three were anterior chamber IOLs. Twenty-eight of the posterior chamber IOLs had circular optics and flexible haptics; the rest were silicone plate IOLs.

“These eyes tended to have complicated presentations with many associated abnormalities including vitreous prolapse into the anterior chamber, dislocated lens fragments, vitritis, inflammatory glaucoma and retinal detachment,” Dr. Kokame said. “The dislocations usually occurred spontaneously, but one case developed after blunt ocular trauma, two silicone plate lenses dislocated after YAG capsulotomy and two anterior chamber IOLs subluxated after retinal surgery.”

The majority of lens dislocations, 59% of the cases, occurred more than 1 month after implantation. Some lenses take up to 20 years to dislocate. The mean time interval for dislocation was 30 months.

Repositioning, exchange, removal

---Externalization of haptic of dislocated posterior chamber IOL through a clear corneal incision. Sutures are tied to the externalized haptic, then retrieved through a pars plicata sclerotomy 1 mm posterior to the limbus underneath a scleral flap.

Repositioning the IOL was done in 34 of the cases of dislocation. In the other cases, the lenses were exchanged in five cases and removed in two, one of which had a poor prognosis and multiple recurrent retinal detachments.

“Of the 34 repositioned cases, the means of support for the repositioned IOL included capsule support only in 11 cases, capsular support for one haptic and scleral fixation suture for one haptic in 9 cases, scleral fixation for both haptics in 12 cases and iris sutures for both haptics in 2 cases,” Dr. Kokame said.

In 28 of the repositioned cases, the IOL was repositioned after one procedure. Of the remaining cases, five posterior chamber IOLs and one anterior chamber IOL, the implants re-dislocated 5 weeks to 8 months after repositioning.

“In one case, the repositioned anterior chamber IOL re-dislocated concurrently with multiple retinal detachment surgery,” Dr. Kokame said. “In three cases, the posterior chamber IOL re-dislocated after repositioning over residual capsule only. Two cases dislocated after support with capsule for one haptic and scleral fixation suture for the other haptic and one case re-dislocated following scleral fixation suture for both haptics. No case of re-dislocation has been noted after the use of the haptic externalization procedures for scleral fixation.”

Scleral fixation

Scleral fixation is achieved by creating a loop of suture around the haptic of the dislocated IOL.

“This can be done internally by a variety of maneuvers within the eye to loop the suture around the haptic of the dislocated IOL. The suture loop can also be performed externally, securing a suture knot around the haptic after externalization of the haptic followed by subsequent re-implantation of the haptic,” Dr. Kokame said

Although externalization of the haptic is traditionally done through a sclerotomy, Dr. Kokame said he has recently done it through a clear corneal incision.

“A scleral flap is initially performed,” he said. “A pars plana vitrectomy is performed and the IOL is retrieved with straight vitreous forceps. The IOL is subluxated from the vitreous cavity into the anterior chamber. A clear corneal incision is made and the haptic is externalized. A 10-0 polypropylene loop is secured around the haptic. In this normal implantation position for the IOL it is easy to reposition the other haptic over residual capsule.” A similar fixation technique can be used for the other haptic, if no residual capsular support is present.

The sutures are retrieved through the sclerotomy site, and the surgeon uses a scleral fixation bite to close the sclerotomy and secures the sutures around the haptics to the sclera.

“The advantages of this technique are that it stabilizes the IOL and puts it into the usual implantation position in the anterior chamber, allowing easier placement of the remaining haptic over residual capsule,” Dr. Kokame said. “There is good visualization of haptic externalization, which minimizes haptic damage. This technique is easy to perform and in an eye with a good anterior vitrectomy, could be performed by anterior and posterior segment approaches.”

For Your Information:

• Gregg T. Kokame, MD, can be reached at 321 N. Kuakini St., Ste. 307, Honolulu, HI, 96817; (808) 523-6131; fax: (808) 487-3699; email: retinahi@aol.com. Dr. Kokame has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.