01 · Establish temporary control
Use the retractors before instability compromises phaco.
I do not wait for dramatic lens subluxation before using them. If instability of the bag is beginning to compromise safe phaco, placing retractors early may prevent further zonular damage and a much more difficult complication later.
My usual indication is significant zonulysis identified before or during surgery, with an intact continuous capsulorhexis and enough remaining control for the bag to be preserved. Any instability that threatens safe phaco may justify temporary equatorial support.
02 · Device selection
The retractors I use.
I use MST Capsule Retractors, Chang Modification. Unlike an iris hook, the distal end is designed to reach the capsular equator and support a broader area of the bag.
The Chang modification has a closed posterior loop. According to MST, this preserves broad contact with the capsule while minimising the rare risk of a capsular tension ring becoming entangled in the retractor. It is a risk-reduction feature rather than a guarantee that entanglement cannot occur.
I usually place four retractors, approximately one in each quadrant. Supporting the bag from several directions gives better control than simply pulling against the visibly weak sector.
03 · Plan before entering
Plan the paracenteses before making them.
The paracenteses must be large enough for the retractors. The manufacturer recommends an incision of at least 0.8 mm.
I direct each paracentesis approximately 30–45 degrees down towards the capsular equator. A horizontal tract, similar to one used for an iris hook, gives the capsule retractor a poor approach to the bag.
The location of any possible Hoffmann pocket should also be decided in advance. A poorly placed paracentesis can occupy the area later needed for placement and fixation of a capsular tension segment.
The external parts of the retractors must remain clear of the eyelids. Excessive eye movement can cause a retractor to catch against a lid and transmit further traction to an already weak bag. Retractor migration should also be checked throughout the case.
04 · Placement and sequence
Place the support before phaco.
- Complete an intact continuous capsulorhexis.
- Create the planned paracenteses.
- Pass each retractor beneath the rhexis margin until it supports the capsular equator.
- Advance the silicone stopper and apply sufficient tension to stabilise the bag.
- Reassess the position and movement of the lens before proceeding.
The aim is controlled support rather than excessive traction.
Viscodissection and an early CTR
Once the retractors are supporting the bag, I use viscodissection to create space between the soft lens matter and the capsule.
If the bag requires early circumferential support, a capsular tension ring can then be injected while the retractors maintain equatorial stability. The Chang modification is designed to reduce the risk of the CTR becoming caught within the retractor loop, but I still follow the ring carefully as it advances around the bag.
05 · Reduce stress on the bag
Lower the fluidic forces.
I reduce the fluidic settings when operating on a lens with substantial zonular weakness. This includes lowering vacuum, aspiration flow rate and bottle height or infusion pressure.
The precise settings depend on the phaco system and the stage of surgery. The principle is to reduce surge and unnecessary movement of the capsular bag while still maintaining a stable chamber.
06 · Reassess long-term support
When a CTR may not be enough.
A standard CTR provides circumferential equatorial support, but it does not provide scleral fixation.
In my operative planning, when preoperative UBM suggests more than five clock hours of zonular loss, I plan for an Ahmed Type 6E capsular tension segment together with a CTR. This is how I approach these eyes rather than a universal threshold for every surgeon or case.
Keeping the segment and ring as separate devices gives me greater control and allows the CTR to be injected independently. The CTR supports the circumference of the bag, while the capsular tension segment provides focal support that can be secured to the sclera.
After the retractors are released, persistent movement of the bag–IOL complex indicates that a CTR alone has not provided sufficient support.
07 · End sequence
Remove the retractors in the correct order.
After the CTR and IOL have been inserted, I normally loosen and remove the retractors before irrigation and aspiration of the viscoelastic.
If a capsular tension segment has not yet been inserted, I leave one retractor in place temporarily. It keeps the bag open and controlled while the segment is introduced. Once the segment has been positioned and secured, the remaining retractor can be removed and the viscoelastic aspirated.
08 · Common errors
Errors that reduce control.
Making the paracentesis too small
A retractor should pass through its paracentesis without being forced. The tract must also allow the instrument to maintain its intended approach towards the capsular equator.
Directing the tract too horizontally
An iris-hook-style horizontal tract gives the capsule retractor a poor angle to the equator. I direct the paracentesis down towards the bag instead.
Blocking a future Hoffmann pocket
If permanent focal support may be required, the intended pocket and fixation site should be planned before the retractor paracenteses are made.
Missing retractor movement
I watch for migration throughout the operation. I also make sure the external retractor does not catch against the eyelid during excessive eye movement and transmit additional traction to the bag.
Removing all temporary support too early
If a capsular tension segment still needs to be inserted, removing every retractor may allow the bag to close or become less controllable. Leaving one retractor temporarily can preserve the space needed for segment insertion.
Capsule retractors create the temporary stability needed to complete phaco safely. They do not determine whether the bag has adequate long-term support. I reassess that after the retractors are released.