Capsular tension rings are flexible plastic loops which are designed to exert outward force at the capsular bag equator to help distribute forces and help support areas of zonular loss. They are very useful in cases of trauma with focal zonular loss, and may provide additional stability in certain cases of progressive zonulopathy like pseudo-exfoliation.
In this case, the patient sustained an air-bag injury in a car accident many years ago. He did not recall this until after the surgery. At the pre-operative consultation, no zonular weakness was detected, but early during surgery it became obvious.
The CTR can be inserted at any time during the cataract surgery after the capsulorhexis has been created. It does require an intact and strong capsulorhexis as well as an intact posterior capsule. Placing the CTR at the beginning of the case can provide additional stability during nucleus removal, but it can make cortex removal more difficult because it traps it at the capsular bag equator. For this reason, the common saying is to place the CTR as soon as you need it but as late as possible.
In this case, I was able to wait until the cortex was removed prior to placing the CTR. When inserting the CTR, there should be no resistance — it should move smoothly along the capsular bag equator. If there is resistance, it may be pushing through the capsule and you should stop, refill the capsular bag with viscoelastic, and try again.
Once the CTR is placed, you can simply place your routine single-piece acrylic IOL in the capsular bag. In some cases, another option would be to place a three-piece IOL with the haptics in the sulcus and the optic captured posteriorly through the capsulorhexis.
Note that you do not have to use a CTR in all cases of focal zonular weakness. You can place the haptic towards the area of weakness to act as a bolster. And in other cases of global zonular weakness, you can take a conservative approach.
Click below to learn how to use a Capsular Tension Ring:
Dr. Devgan,
What do you believe is the best positioning of an IOL with a quadrant of loose zonules and no CTR available? A 3 piece in the bag with a haptic supporting the area of weakness or a 3 piece in the sulcus away from the area of weakness? Also, it seems that a 3-piece IOL haptic would provide more tension (support) in the area of weakness than a single piece IOL.
What do think about solely implanting 3-piece IOLs in patients with zonular issues? My thoughts are that a 3-piece can be sutured in at a later time if it becomes dislocated vs a single piece would have to be ex-planted. I am sure this depends on the surgeon’s experience and the risk he or she perceives of the lens dislocating.
As always, thanks for posting these great videos.
– George
good points.
without a CTR, I would place the haptics in the capsular bag pushing outward to the area of zonular loss. Like this:
https://cataractcoach.com/2018/09/27/cataract-surgery-with-traumatic-zonular-loss/
or you can place the haptics in the sulcus 90 degrees away from the area of zonular loss and then do optic capture through the capsulorhexis
remember that the entire complex of IOL+CTR+contracted capsular bag can be sutured in place if needed.