Eyeworld

SEPTEMBER 2023 | EYEWORLD | 27 C About the physicians John Hart Jr., MD Associates in Ophthalmology Farmington Hills, Michigan Yuri McKee, MD East Valley Ophthalmology Mesa, Arizona Reference 1. Page TP, et al. 'S' means stop! Critical examination of capsular tension ring move- ments with Miyake-Apple video analysis. J Cataract Refract Surg. 2021;47:379–384. Relevant disclosures Hart: None McKee: None by Ellen Stodola Editorial Co-Director A basic CTR is designed to redistribute the strength of healthy zonules to areas of zonular weakness. "Up to 90 degrees of continuous zonular weakness can be remedied with a basic CTR," he said. "If 90–180 degrees of zonular damage are present, one or two Ahmed seg- ments secured to the sclera via the ciliary sulcus would be appropriate. For more than 180 de- grees of zonular compromise, a Cionni ring with two eyelets for scleral fixation can be used." Dr. McKee noted that it may sometimes be obvious ahead of surgery that a CTR or support segment will be needed. In other cases, the zonular weakness may not be apparent until during surgery. "The ideal time to place the CTR is after cortical cleanup and prior to the placement of the IOL in the capsule," he said. "In some cases, the cortical cleanup may cause worsening zonular weakness. In these cases, the CTR can be placed prior to cortical cleanup to stabilize the capsule, but this could make corti- cal cleanup more difficult." When to use a CTR Dr. McKee said that certain genetic conditions, such as Marfan syndrome, Weill-Marchesani syndrome, or Ehlers-Danlos syndrome, are associated with zonular abnormalities. "Sup- port segments may be required during cataract surgery for these cases," he said. Trauma is likely the most common cause of focal zonular damage, he said. Pseudoexfolia- tion syndrome is associated with global zonular weakness and late dislocation of an IOL-capsule complex. The placement of a CTR in pseudoex- foliation does not necessarily increase support for the capsule or prevent late dislocation of the IOL, Dr. McKee said, but it may help to reduce capsule phimosis, and it does offer a stable sub- strate for fixation of a subluxated IOL-capsule complex that can occur many years after the original cataract surgery. In cases where a single-piece toric acrylic IOL is used, Dr. McKee said some surgeons think that a CTR can help to reduce the postoperative rotation of the toric IOL. The Henderson CTR may be especially useful due to the undulating Ahmed capsular tension segment that has just been inserted into the eye; it has a 9-0 Prolene suture threaded through the fixation element Traumatic zonular dialysis Source (all): John Hart Jr., MD Contact Hart: j.c.hartjr@sbcglobal.net McKee: mckeeonline@mac.com continued on page 28 design. Highly myopic eyes with a deep anterior chamber and/or a large capsule may be better candidates for using a CTR to help prevent rota- tion of a toric IOL, he said. Dr. Hart said that he uses a standard CTR in all his pseudoexfoliation syndrome cataract cases, all cases with documented blunt trauma, cases with zonular dialyses, and cases where he visualizes the equator of the capsular bag (indicates stretched zonules). "I commonly use CTRs in patients with an axial length greater than 26 mm. I use them routinely in patients with an axial length great- er than 26 mm where I am placing a toric IOL. If I have to reposition a toric IOL because it has

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