surgical pearls
Utilizing Capsular Tension Rings
Advice for helping you to determine when to use these surgical supports.
By Kenneth J. Rosenthal, M.D.

During difficult and complicated cataract surgery where the capsular bag or zonules can become compromised, capsular tension rings (CTRs) have become a great tool. But many surgeons are nervous about using them because they're more afraid about misusing them, rather than not using them at all.

To help remedy that situation, in this article, I'll point out the preoperative and intraoperative clues that indicate the need for a ring, and also offer some intra-op pearls.

Preoperative CTR Clues

Preoperatively at the slit lamp:

► look for signs of zonular pathology, including phacodenesis, a deep anterior chamber, increased retro-iridal space, vitreous in the anterior chamber or a history of ocular trauma

► examine the iris, lens, cornea and anterior chamber angle for pseudoexfoliative material

► every patient should have gonioscopy to look for occult pseudoexfoliation.

Intraoperative CTR Clues

While those clues can be easy to spot, there are times when you won't be able to tell a ring is needed until after surgery has already begun. Intraoperative clues you should look for include:

► an unstable anterior chamber

► trampolining of the iris or hypermobility of the lens during hydrodissection, capsulorhexis or phacoemulsification.

The insertion of a CTR, such as Advanced Medical Optics' StabilEyes, Alcon's ReFORM, or Morcher's CTR (Morcher GmBH, distributed by FCI Ophthalmics), can reduce the load on zonular tension by assisting elastic recoiling of the zonules. The ring also allows support of damaged zonules by transferring forces from existing intact zonules and re-expanding and re-tensioning the capsular bag.

Timing and Technique

Surgeons should remember that whether they are inserting the CTR before or after phaco or IOL insertion, it is best to insert when zonulopathy is first recognized.

That said, whenever possible, the capsular tension ring should be inserted as late in the surgical case as is possible, to avoid entrapment of cortex, preferably after cortical cleanup. But if a CTR is necessary to assist in supporting the areas of zonular deficiency earlier in the case, surgeons may find the following technique useful in avoiding cortical entrapment.

After capsulorhexis, and before nuclear disassembly, remove as much anterior and equatorial cortex as possible using either the phaco handpiece or bimanual irrigation/aspiration. Then, place a retentive viscoelastic within the capsular bag, displacing the nucleus and any remaining cortical fibers posteriorly.

With a now-clear area in the anterior portion of the intracapsular space, place the capsular tension ring, just hugging the capsule as anteriorly as possible. With the ring anterior and remaining lens material posterior, you will not trap cortex.

Surgeons should continue to learn all they can about the various ring designs, as well as new insertion techniques as they're discovered, discussed, and presented. They should be familiar and comfortable with these rings.

The first time a surgeon uses a capsular tension ring, he or she should do so in a case with more mild zonular disease.

The keys to success are paying attention to the right clues and knowing how to insert beforehand. In the future, additional clues and indications may present themselves, and CTRs will prove even more vital in even more cases.

Dr. Rosenthal is surgical director of Rosenthal Eye and Facial Plastic Surgery in Great Neck, NY, and Adjunct Assistant Professor of Ophthalmology, University of Utah. He has been in private practice in Great Neck for 21 years.