This article is more than 5 years old. Information may no longer be current.
Options for weak zonules during phaco include CTRs
Click Here to Manage Email Alerts
DANA POINT, Calif. — The capsular tension ring is a newly available surgical option for stabilizing the capsule in patients with weak zonules. A surgeon here described use of the rings in complicated cataract cases.
David F. Chang, MD, updated attendees here at the Ocular Drug and Surgical Therapy Update meeting on two types of capsular tension ring (CTR) – the Morcher CTR, which was approved by the Food and Drug Administration last year, and the Cionni variation of the CTR, which has not yet received U.S. marketing approval.
Both devices are manufactured by Morcher in Germany, and the approved device is available in the United States through FCI Ophthalmics.
“Corneal tension rings are good, but they are not a panacea for the range of zonular defects possible,” Dr. Chang said. Other options when surgeons are faced with severe cases of zonular dehiscence include iris retractors to hold the capsule in place and capsular tension segments, he added.
CTRs can maintain the zonular forces that intact zonules would, Dr. Chang said, holding the capsule in place. They may also retard posterior capsule opacification with a barrier function in the capsular fornix. On the downside, they can potentially damage the capsular bag on insertion, and they may impede cortical cleanup, Dr. Chang said.
The timing of placement of the CTR is not an issue, Dr. Chang said; it can be inserted any time after the capsulorrhexis is created, before or during phaco, he noted. The rings are inserted with forceps or through injectors. After CTR placement, the IOL is implanted in normal fashion. CTRs can also be placed after IOL implantation, he said.
Dr. Chang advised surgeons be cautious with the rhexis edge because the CTR will be adding pressure to it. The hook should bear the brunt of the pressure, he said. Good visualization and the support of the existing zonules are needed for safe implantation, he said.
Iris retractors can be used for holding the capsular bag in place in cases with large zonular defects, Dr. Chang said.