Using the Capsular Tension Segment: Tips and Pearls

The CTS is indicated for severe zonular instability, typically greater than four clock hours of zonular dehiscence, or profound generalized zonular weakness and phacodonesis. Depending on the degree of zonulysis, one or two CTS devices may be used, and unlike the CTR or mCTR, the CTS can be placed in the presence of an anterior capsule tear or small posterior capsule rent. The advantage of the CTS is its versatility in acting both as an intraoperative support device and postoperative fixation implant. 

As a device, it can be placed at any time after capsulorhexis. Because no dialing technique is needed, it can be placed in the capsular bag atraumatically, typically in the quadrant of greatest zonulysis. An inverted iris retractor is placed through the central fixation eyelet to provide intraoperative support, while the CTS provides localized expansion of the capsular equator. Suture fixation to the sclera—typically with 9-0 polypropylene—is used for postoperative support of the capsular bag. Sutures may be passed either before or after lens extraction. 

Surgical Technique

The first priority in managing profound zonular instability is to create a continuous tear capsulorhexis. Iris retractors can provide necessary counter-traction during this step.

Following capsulorhexis formation, the CTS is inserted either by pre-placing sutures before lens extraction or by suturing after lens extraction. This decision is made based on how challenging it will be to pass the needle and sutures through the eye with the crystalline lens in the bag. If there is enough space to pass needles without significant risk of capsule trauma, the sutures may be preplaced. However, if there is a concern, it may be prudent to wait to pass sutures until after lens extraction, when the capsular bag is decompressed and can be pushed posteriorly with viscoelastic. Either way, the CTS is inserted after capsulorhexis.

When passing sutures, an ab-externo technique is preferred to facilitate exact placement through the sclera and to provide greater control of the needle in the eye. A very superficial scleral groove is made, typically 1.5 mm from the limbus in the area of intended suture fixation. After placing a generous amount of cohesive viscoelastic under the iris and over the capsular bag in the quadrant of interest, a 26-gauge hypodermic needle is passed in the groove through the sclera to capture or “dock” one end of a double-armed 9-0 polypropylene suture that has been passed through a corneal incision (Figure 3a). This is then withdrawn back through the sclera and out of the eye. After it is passed through the fixation eyelet of the CTS (Figure 3b), the other end of the 9-0 polypropylene, is then passed in a similar fashion adjacent to the initial sclera pass (Figure 3c).

Courtesy of Iqbal Ike K. Ahmed, MD

Figure 3. CTS Insertion

After viscodissection to expand the anterior capsular bag to the equator to allow for placement of the CTS (Figure 4), it is placed in the anterior chamber via the main corneal incision and brought to the intended quadrant of placement (Figure 5). 

Courtesy of Iqbal Ike K. Ahmed, MD

Figure 4. Viscodissection expands the anterior capsular bag to the equator.

Courtesy of Iqbal Ike K. Ahmed, MD

Figure 5. CTS is placed in the anterior chamber and brought to the intended quadrant of placement.

Although sutures have been placed through the CTS, an inverted iris retractor, positioned through a small paracentesis, is used to support the CTS intraoperatively during phacoemulsification (Figure 6). It is important to ensure that the CTS is in position within the capsular bag.

Courtesy of Iqbal Ike K. Ahmed, MD

Figure 6. Inverted iris retractor provides support for the CTS.

At this point, phacoemulsification is performed with adequate support in the area of zonulysis provided by the CTS/iris-retractor complex (Figure 7). It is critical to maintain the anterior chamber at all times to prevent vitreous prolapse.

Courtesy of Iqbal Ike K. Ahmed, MD

Figure 7. With CTS in place, phacoemulsification is performed.

A CTR is often placed either before or after lens extraction (Figure 8) for circumferential support. In essence, the combination of the CTS and CTR provide similar support as a mCTR, but provide increased flexibility and handling. After IOL implantation within the capsular bag, the polypropylene suture is tied and the knot is rotated into the sclera to avoid erosion through the conjunctiva (Figure 9). It is important to avoid tying the suture too tight, which may cause decentration of the IOL toward the suture knot.

Courtesy of Iqbal Ike K. Ahmed, MD

Figure 8. CTS remains in good position following phacoemulsification and insertion of CTR.

Courtesy of Iqbal Ike K. Ahmed, MD

Figure 9. Polypropylene suture is tied and the knot is rotated into the sclera to avoid erosion through the conjunctiva.

This procedure provides for a well-centered IOL within the capsular bag, with a CTS placed in the quadrant of zonulysis sutured to sclera (Figure 10). Should the degree of zonular instability be greater or global, a second CTS can also be used. 

Courtesy of Iqbal Ike K. Ahmed, MD

Figure 10. Final CTS placement in the quadrant of zonulysis. 

Discussion 

The CTS provides another option in the management of cataracts with profound zonular instability. Because the CTS can be placed atraumatically within the capsular bag, it is a flexible device. The use of an iris retractor during the procedure allows the CTS to behave as a large retractor, and suture fixation can be performed either before lens extraction or afterward, in which case the CTS can be displaced from the equator and brought to the anterior chamber to facilitate passage of suture needles through the central eyelet. The CTS also reduces the need for vitrectomy if vitreous prolapse was not present preoperatively.

Over five years of experience we have found that the CTS provides excellent centration and maximizes results.⁴ To obviate concerns of suture breakage, we have advocated using 9-0 polypropylene as the suture of choice. We are also exploring the use of other suture materials such as Gore-Tex and polyester.

References

1. Jacob S, Agarwal A, Agarwal A, et al. Efficacy of a capsular tension ring for phacoemulsification in eyes with zonular dialysis. J Cataract Refract Surg 2003; 29:315–321.
 
2. Moreno-Montanes J, Sainz C, Maldonado MJ. Intraoperative and postoperative complications of Cionni endocapsular ring implantation. J Cataract Refract Surg 2003; 29:492–497.
 
3. Ahmed II, Crandall AS. Ab-externo scleral fixation of the Cionni modified capsular tension ring. J Cataract Refract Surg 2001; 27:977–981.
 
4. Hasanee K, Ahmed II K, Kranemann C, Crandall AS. Capsular tension segment: clinical results and complications. American Academy of Ophthalmology Meeting, New Orleans, Louisiana; October 2004. Paper Session. 

Author Disclosure

The authors state that they have no financial interest in any of the products or techniques discussed in this article.