January 2009

 

CATARACT/ IOL

 

“Bizarre” appearance of subluxed IOL, increasingly common


by Rich Daly EyeWorld Contributing Editor

   

Removal of mobile IOLs and capsular bag complexes that are causing hyphema or glaucoma is possible with the right tools and approach

Example of a dislocated IOL (in the bag nasally-left side-and temporal side through capsular rent) Source: S. Holtz, M.D.

A dislocated IOL seven years post-op presented a challenge when it was discovered as the likely source of hyphemia and possibly glaucoma in a recent case.

Although the case appeared unusual, an expert in IOL complications said such cases are an increasingly common phenomenon.

The case presented to Glen Weiss, M.D., Garnerville, N.Y., recently when a 75-year-old female patient with a history of pseudoexfoliation who had undergone uncomplicated phacoemulsification and implantation of AcrySof SA60AT (Alcon, Fort Worth, Texas) in the capsular bag presented with complications.

The patient, who had received her implants OD in 2001 and OS in 2003, had been without complications until February 2008 when she presented with blurred vision OD. At the time, she had no pain, redness, photophobia, or any other symptoms.

Dr. Weiss’ exam revealed mild corneal epithelial edema, diffuse microhyphema with a gonioscopy finding of some blood settling in the inferior angle, mild pseudo-phakodonesis, and an IOP of 40 mm Hg.

“Cycloplegia and glaucoma drops eventually resolved the hyphema, controlled the IOP, and cleared her vision back to 20/20,” Dr. Weiss said, about his initial treatment.

The patient’s vision remained stable on a regimen of cyclopentolate (various manufacturers) and Combigan (ophthalmic brimonidine and timolol, Allergan, Irvine, Calif.) until she presented five months later with blurred vision. The same “bizarre” symptoms were again present, Dr. Weiss said. An ultrasound biomicroscopy revealed that one of the haptics of her single piece acrylic IOL had eroded into the ciliary processes inferiorly.

“Pilocarpine was tried to perhaps move the IOL away from the ciliary processes, but it caused intense pain,” Dr. Weiss said.

Dr. Weiss planned to remove the IOL and allow the hyphema to resolve along with the glaucoma, and then place an AC IOL in two to three months. However, removal of an acrylic IOL from the capsular bag years after implantation is fairly unusual and highly complicated with the presence of pseudophakodonesis and extended time in the eye.

Assessing the challenge

Such cases of subluxed and mobile IOL and capsular bag complexes are becoming increasingly common, according to Iqbal (Ike) K. Ahmed, M.D., assistant professor, University of Toronto, Toronto, and clinical assistant professor, University of Utah, Salt Lake City.

“This complication appears to be on the rise, and as a referral center, I regularly operate on these types of cases,” Dr. Ahmed said. “Sometimes it is nine to 10 years before a lens can dislocate like this.”

The keys to addressing such cases lie in the right equipment and the right approach in a controlled, closed system, he said.

For Dr. Ahmed, the lesson of such cases is to intervene early.

Surgical approach

His first step is to fully understand the patient’s glaucoma status. Such cases with moderate-to-advanced glaucoma can often rapidly degenerate either before surgery or after surgery. In cases where glaucoma is confirmed as a concern, Dr. Ahmed suggested combined surgery that adds a tube shunt as part of the IOL procedure. Dr. Ahmed said that in his early approach to dislocated IOLs in glaucomatous patients, he would perform separate procedures and the glaucoma would “considerably” progress after the IOL surgery.

“Bottom line, they can tip over in this situation, and quickly,” he said.

To resolve the patient’s IOL-induced complications, Dr. Ahmed suggested removing the entire IOL/bag complex because it is a visual obstruction during surgery. In the presence of weak zonules, the surgeon should be able to pull out the capsular bag with micrograspers either after the IOL is removed or along with the IOL. Dr. Ahmed injects dispersive OVD behind the capsular bag when it is partially removed to keep the vitreous contained. It is critical to avoid overfilling the chamber with OVD used to keep the anterior chamber (AC) formed and to viscodissect the bag open.

Other intra-op keys include never letting the AC shallow and always obtaining good pupil dilation—use iris hooks if necessary to allow visualization of the entire IOL optic and at least some of the haptic.

Iris hooks used on the capsulorhexis also are helpful to stabilize the bag. The hooks hold highly mobile IOLs in place and can help expand and stretch the continuous curvilinear capsulorhexis when it is time to remove the IOL from the bag.

Specialized tools are another key to this surgery. Dr. Ahmed suggests surgeons use micro-instrumentation, including micrograspers to hold and maneuver the capsular bag and IOL, as well as IOL-cutters to cut the lens.

Surgical outcome Dr. Weiss used the approach described by Dr. Ahmed, as well as micro-instruments such as micro-scissors for cutting the capsulorhexis and removing the lens from the bag. The most challenging part of the surgery was removing the haptics from the capsular bag as the zonules started to give way.

“I just amputated the haptics from the optic with the lens cutter, bisected and removed the optic, and then removed the haptics with the entire capsular bag,” Dr. Weiss said.

The surgery was completed without vitreous loss and while leaving the anterior hyaloid membrane totally intact.

If the patient’s glaucoma remains controlled for two months, Dr. Weiss plans to implant an AC IOL.

Editors’ note: Drs. Weiss and Ahmed have no financial interests related to their comments.

Contact information

Ahmed: 905-820-3937, ike.ahmed@utoronto.ca
Weiss: 845-947-2240, gweissmd@gmail.com

       
“Bizarre” appearance of subluxed IOL, increasingly common “Bizarre” appearance of subluxed IOL, increasingly common
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