Weak zonules a challenge for cataract surgeons
KOLOA, Hawaii — Weak zonules can be a challenge during cataract surgery but following a few steps can help the surgeon meet that challenge, according to a speaker here.
“Those weak zonules are so easy to tear; remember the posterior capsule is not taut,” David F. Chang, MD, said at Hawaiian Eye 2017. “Our goals are not only to preserve the capsule but also to avoid late bag IOL dislocation.”
David F. Chang
First, complete the capsulorrhexis – at all costs, he said. A smaller diameter may be needed that can be enlarged later.
“I don’t worry about making it large enough, I just worry about completing it,” said Chang, who was chosen as Speaker of the Day.
Second, use capsule retractors, even iris hooks, as a capsule retractor if needed. The capsule retractors act as artificial zonules.
“The zonules aren’t strong and the bag wants to rotate,” Chang said, so capsule retractors provide capsular counterfixation.
Also, continually reinflate the bag with dispersive viscoelastic to stretch it open.
“With weak zonules, the posterior capsule is so flaccid it wants to ride up right into the aspirating tip,” Chang said. “So I pause, use a dispersive and push the capsule back.”
Use bimanual inspiration/aspiration ”if you’re in trouble,” delay inserting a capsular tension ring, and have a plan for converting to an extracapsular convert to extracapsular cataract extraction, Chang said.
Finally, Chang attempts a two-point fixation of the bag and IOL complex to prevent late rotation and capsule contraction. – by Rebecca Forand
Chang D. Phaco with weak zonules. Presented at: Hawaiian Eye; Jan. 14-20, 2017; Koloa, Hawaii.
Disclosure: Chang reports that he is consultant for Abbott Medical Optics.