Fig. 1
Initiation of CCC with central puncture
Either the tip of the cystotome or a forceps is used to fold over the capsular flap akin to a folded napkin (Fig. 2).
Fig. 2
Turning over the flap
Next, the tear is led in a circular fashion (Fig. 3) to complete the opening (Fig. 4). Control is achieved by grasping about 2 clock hours away from free flap edge closest to the leading fold of the capsule. If possible, avoid grasping the fold itself or very close to the leading edge which could lead to an unpredictable tear path. If using a cystotome to complete the CCC, use enough downward friction force to tear the flap around. Too much downward force could lead to an inadvertent puncture of the underlying capsule and/or cortex. While frequent regrasping of the flap will offer exquisite control, experienced surgeons find that up to 3–4 clock hours can be completed before regrasping the flap.
Fig. 3
Leading the tear around
Fig. 4
The completed CCC with PCIOL
Additionally, an understanding of shearing and ripping vector forces described by Seibel is key to directing the path of the tear [7]. In short, a shearing force is applied in the direction of the tear which requires less force. In contrast, a ripping force is applied more centrally to the direction of the tear which offers less control but can redirect the path of a straying tear.
Advantages of the CCC
Resists anterior capsular radial tears which could lead to posterior capsular rupture (PCR).
Allows for safe hydrodissection and in-the-bag lens rotation.
Permits easier cortical clean up without concerns for aspiration of anterior capsular tags.
Tolerates meticulous anterior capsular polishing of lens epithelial cells.
Can be sized appropriately depending on the size of the lens.
Promotes stability and centration of the IOL.
Continuous overlap of the anterior capsular over the optic may help to reduce formation of posterior capsular opacification (PCO).
In the event of PCR, it allows for sulcus IOL implantation with optional optic capture.
Disadvantages of the CCC
It takes more experience to adequately master.
A small CCC can preclude safe prolapse of the lens into the anterior chamber.
An overly large CCC may promote IOL dislocation from the capsular bag.
Excellent visualization of the anterior capsule is required and may not be possible without capsular stains.
Instrumentation
Bent cystotome needle – can be used either through a paracentesis or main scleral tunnel incision.
Capsulorrhexis forceps – some unique designs are available with longer shafts for scleral use or micro designs to be used through a paracentesis.
Capsular stains should be available during cases with poor red reflex or used after puncture of the capsule to visualize the tear (e.g., when cortical material fluffs up and obscures the view).
The CCC can be performed with either a cystotome or forceps, while the AC is stabilized with viscoelastic or using a cystotome with a fluid handle connected to continuous irrigation fluid.
Unique Complications
If a tear radializes beyond rescue, another tear from the opposite direction can be led around to complete the capsular opening. At this point, the surgeon should assume that an anterior capsular rent is at risk of extending to the zonules and care should be taken during hydrodissection and lens delivery.
Can Opener
The can opener capsulotomy was widely used during the era of cataract surgery when large incision extracapsular cataract surgery was in vogue. In the 1980s, a transition from the can opener to the CCC occurred as the risk of anterior capsule run outs was decreased with the use of the CCC [8].
Description of Technique
The can opener capsulotomy and its variations such as the postage stamp capsulotomy are made by connecting individual breaks, or tears, in the anterior capsule. The eye should be fixated with either a toothed .12 mm forceps or via other fixation techniques that do not exert undue pressure on the globe or distort the cornea. The tears may be created with a needle, bent cystotome, or other sharp instrument. In Fig. 5, an initial puncture with a subsequent pulling motion to enlarge the initial puncture is displayed.
Fig. 5
Initial puncture into capsule with cystotome
The initial direction of the pulling motion can be toward the center or more tangential in the direction of the subsequent capsule puncture to the left or right. In Fig. 6, the can opener is continued to the right, and the subsequent puncture is connected to the initial puncture. The surgeon should connect each puncture with the previous puncture, which can be done by sweeping the instrument in the direction of the previous tear.
Fig. 6
Subsequent capsule puncture adjacent to initial tear
Subsequent punctures are made in a circumferential manner connecting each puncture. Figures 7 and 8 show this continuous circumferential tearing. Note the size of the capsule tears is exaggerated in the figures for illustrative purposes (Fig. 9). The number of punctures in a can opener capsulotomy can vary widely depending on the technique; however, many feel larger numbers of tears may decrease the risk of radial extension of the capsulotomy. Generally 10–15 tears per quadrant are recommended.
Fig. 7
Connecting each puncture with previous
Fig. 8
Connecting punctures in a circumferential manner
Fig. 9
Completed can opener capsulotomy. Note the size of the individual punctures is exaggerated for illustrative purposes
Advantages of the Can Opener Capsulotomy
Although a learning curve is present, the can opener is considered to be technically easier to master than CCC.
Allows for some hydrodissection and in-the-bag lens rotation.
Tolerates some anterior capsular polishing of lens epithelial cells.
Can be sized appropriately depending on the size of the lens.
The high number of tears in the anterior capsule allows a sharing of forces reducing the risk of a single tear radialization.
Disadvantages of the Can Opener Capsulotomy
Risk of radialization is always present at each subsequent step of surgery, particularly during hydrodissection and delivery of lens.
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