A CTR is a 270 degree open PMMA ring placed in the capsular bag during cataract surgery in cases with zonular instability or weakness.
Aurolab manufactures 3 types of CTR,
All types made from Clinical Quality UV absorbing PMMA, they are
- Capsular tension rings (standard type)
- For cases involving less than 4 clock hours (4 positions) of zonular dialysis, a standard CTR is suitable.
- Cionni rings with single and double loop.
- For cases involving greater than 4 clock hours or progressive zonular damage.
- Capsular tension segment.
- Partial ring used in cases that cannot be supported by CTR.
- Stabilization of the crystalline lens capsule in the presence of weak or absent zonules.
- Pseudoexfoliation (lead to lens capsular damage, most common in glaucoma).
- Prior trauma which leads to Zonulysis( damage of zonules) or capsular rupture.
- Expected complications during phaco surgery.
- Situations in which sudden unfolding of a foldable IOL might cause zonular breakage or dislocation of the IOL.
- Repositioning of IOL decentration.
- Marfan syndrome (results in subluxated lens with weak zonules).
Capsular Tension Ring (CTR):
- CTR is an open-ended,
- flexible horseshoe-shaped polymethyl methacrylate (PMMA) filament.
- with two eyelets at either end.
- It is used in cases involving less than 4 clock hours of zonular dialysis.
- Ensures stable conditions during surgery.
- Prevents capsular fibrosis.
|Model No||CTR 10||CTR 11|
|Overall Diameter||10.00 mm||11.00 mm|
|Closed Diameter||12.00 mm||13.00 mm|
- In cases of profound zonulysis (i.e., greater than 4 clock hours) or extensive progressive zonular dialysis, a standard CTR may not provide adequate centration and stability.
- In these case, a modified CTR designed by Cionni adds a comma-shaped filament attached to the main ring with an additional eyelet that allows it to be sutured to the scleral wall without piercing the capsular bag.
- The eyelet is offset anteriorly to allow it to sit outside the capsular bag.
- A double eyelet configuration is available for cases requiring additional support.
- Cionni with single right eyelet (CCR).
- Cionni with single left eyelet (CCL).
- Cionni with double right & left eyelet (CCLR).
|Model No||CC10L, CC10R, CC10LR||CC11L, CC11R, CC11LR|
|Overall Diameter||12.00 mm||13.00 mm|
|Closed Diameter||10.00 mm||11.00 mm|
Capsular Tension Segment:
- This is a zonular support device that provides support for in-the bag implantation.
- Its versatility enable early or late placement within the capsular bag.
- It can be used in cases that cannot be supported by CTRs.
- It is a partial ring with a fixation hook
- CTR/ Cionni can be implanted manually or with the help of specially designed injector.
- Requires presence of intact capsulorhexis and capsular bag.
- Can be implanted at any step after capsulorhexis, but early placement makes cortical removal more difficult and tedious.
- For these reasons, it is helpful to maintain multiple iris retractors at the capsulorhexis edge to stabilize the capsular bag during phacoemulsification and cortical removal.
- After lens extraction, the iris retractors can be removed once the CTR has been safely implanted into the capsular bag prior to IOL insertion.
- Circular expansion of capsular bags.
- Stablizes conditions during surgery.
- Improves IOL centration.
- Reduces risk of capsular fibrosis.
- Resists capsular shrinkage.