Eyeworld

I CHALLENGING CATARACT CASES SEPTEMBER 2019 | EYEWORLD | 65 to evaluate IOL and haptic position, capsule bag, and Soemmering's ring. Refixation by IOL type The best approach to refixation "is unique to each patient situation," Dr. Schockman said. "When there is an intact IOL/capsular bag complex, the lasso technique for sutured scleral fixation works well, particularly when a CTR or three-piece IOL is present." Dr. Hoffman agreed that care must be taken with single-piece IOLs as too much tension on the sutures may cause them to slip off and "cheese wire" through the capsule. "A single-piece IOL should probably not be fixated to the iris but a three-piece IOL with adequate posterior vitreous or capsule support can be fixated to the iris safely," he said. "If the IOL is completely dislocated into the posterior segment, it will require a pars plana vitrectomy and retrieval and is then best dealt with by per- forming an IOL exchange for a scleral fixated three-piece IOL." "However, in rare instances in which it is important to minimize incision number and size, refixating a one-piece acrylic IOL may be in the patient's best interest," Dr. Schockman continued. "In such situations, radial incisions for the lasso suture should be used. If there is an intact capsulorhexis with some capsulorhexis margin fibrosis, Siegel and Condon describe an elegant technique to suture the anterior capsule to the iris. 1 This can be a very useful tool in eyes with large blebs where conjunctival real estate is limited." Dr. Khandelwal noted that dislocations usually occur due to issues with the zonules or bag. Meanwhile, care must be taken when refixating three-piece IOLs whether to the iris or sclera as the haptics may be weak. Iris vs. sclera The physicians tend to favor scleral fixation over iris fixation—although the latter can work "if there is an intact anterior or posterior capsule that allows support for the optic," Dr. significant Soemmering's ring that could lead to UGH syndrome, an IOL exchange may be best. To assess accessibility via the anterior approach, she recommended examining the patient the week before surgery in upright and supine positions to assess full dislocation and see if the retina is involved. The surgeon should be comfortable with retrobulbar or sub-Tenon's block techniques and preservative-free triam- cinolone-assisted vitrectomy, and backup IOLs should be chosen preoperatively. When evaluating a patient with a sublux- ated/mispositioned IOL, Dr. Fram asks: (1) Can I use the capsule? (2) Can I use the iris for fixation? (3) Can I use the sclera for fixation? Locating IOL dislocation "Location is key," Dr. Khandelwal said. It might seem like just the lens, but often these lenses dislocate in the bag and are attended by weak zonules and disruption in the bag. If an IOL is out of position, the surgeon should evaluate whether it is simple IOL dislo- cation or capsular bag dislocation, generally due to diffuse zonulopathy. While IOL and bag subluxation typically go hand in hand since the IOL is encased in the bag, Dr. Schockman said, "In cases in which the IOL is not within the capsule, or there is an ex- tensive break in the capsule, the IOL or capsule may move separately. Careful examination at the slit lamp is critical in differentiating this and determining a surgical plan." Dr. Schockman has the patient look in all directions in a "dynamic" slit lamp exam to maximize visualization. She suggested having the patient look into extreme side gaze then rapidly fixate on the examiner's ear. "As the globe comes to a stop, if the IOL and bag are not moving as a unit together, they will deceler- ate at different moments," she said. The relative positions of the bag and capsule are often obvious but may be difficult to evaluate in a small pupil. Dr. Khandelwal suggested dilating the pupil some more or using a pupillary expansion device in the OR. Dr. Fram suggested ultrasound biomicros- copy in cases of a small or poorly dilated pupil About the doctors Nicole Fram, MD Clinical instructor Stein Eye Institute University of California, Los Angeles Sumit "Sam" Garg, MD Medical director Gavin Herbert Eye Institute University of California, Irvine Richard Hoffman, MD Clinical associate professor of ophthalmology Casey Eye Institute Oregon Health and Science University Eugene, Oregon Sumitra Khandelwal, MD Assistant professor of ophthalmology Baylor College of Medicine Cullen Eye Institute Houston Samantha Schockman, MD Cincinnati Eye Institute Volunteer instructor University of Cincinnati continued on page 66

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