Misaligned toric IOLs require prompt surgical management

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New tools are facilitating repositioning of a misaligned toric IOL. The corrective procedure is best undertaken sooner than later.

By Cheryl Guttman Krader; Reviewed by Randall J. Olson, MD

Irvine, CA-When IOL misalignment underlies a suboptimal outcome with a toric implant and the problem is identified in the early postoperative period, surgeons should not procrastinate about taking the patient back to the operating room for a repositioning procedure, said Roger F. Steinert, MD.

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“It is easy to open the capsular bag and rotate the IOL within the first several weeks after surgery,” said Dr. Steinert, Irving H. Leopold Professor and Chair, Department of Ophthalmology, University of California, Irvine. “So, if you identify that the IOL is in the wrong place, fix it.”

Strategies for correction

Outlining the steps for correcting toric IOL misalignment, Dr. Steinert said the first task is to determine the exact orientation of the IOL. This is done at the slit lamp, and there are now two free smartphone apps (iHandy level and Axis Assistant) that can help to identify the axis.

The next step is to decide how the IOL should be shifted. While this may be done using the postoperative refraction and vector analysis that will take into account posterior and anterior corneal changes, use of an online tool developed by John Berdahl, MD, and David Hardten, MD, offers a much easier option. Available as a free download at www.astigmatismfix.com, the program requires input of the refractive data, but then it automatically does the mathematical calculations to determine exactly where the implant should be aligned in order to minimize final residual astigmatism.

“This program does the vector analysis for you, uses the refraction, which is the most accurate indicator of what it is you are trying to fix, and takes into account the effects of the posterior cornea and your incision,” Dr. Steinert said.

To reposition the IOL, surgeons can use viscoelastic to viscodissect under the capsulorhexis and free the lens from the capsule. Presumably the axis for proper alignment will have been identified with manually placed ink markings. Use of intraoperative aberrometry or other devices can also be used to confirm the accuracy of the IOL’s position.

Securing the result

When dealing with an implant that rotated after it was initially implanted, surgeons may be concerned about whether or not it will stay in place after repositioning. Dr. Steinert said there are two options to consider for stabilizing the IOL. One approach, which is probably the preferred technique, would be to insert a capsule tension ring, he said.

Alternatively, in eyes with a capsulorhexis <6 mm in diameter, surgeons can perform anterior capture of the optic, leaving the haptics in the capsular bag.

However, Dr. Steinert cautioned there is the potential for iris chafe by a sharp-edged optic. Therefore, before undertaking this technique, surgeons need to ascertain there is adequate clearance between the iris and anterior capsule.

Roger F. Steinert, MD

E: steinert@uci.edu

This article was adapted from Dr. Steinert’s presentation at the 2014 meeting of the American Academy of Ophthalmology. Dr. Steinert is a consultant to Abbott Medical Optics and WaveTec Vision. He receives grant support from Abbott Medical Optics.