Continuous curvilinear capsulorhexis (CCC) is a surgical technique that creates a circular opening in the anterior lens capsule during cataract surgery. Derived from the Greek word “rhexis” meaning “to tear,” it is also called capsulorhexis.
Before the 18th century, cataract removal was performed by “couching,” pushing the lens backward into the vitreous. In the mid-18th century, Jacques Daviel developed a technique for lens nucleus extraction using a cystotome, giving rise to the concept of anterior capsulotomy.
Subsequently, various techniques were attempted, including the “can opener” method, “envelope” method, and “Christmas tree” method, but all led to edge tears (run-out) or capsule contraction.
Continuous curvilinear capsulorhexis was reported successively between 1985 and 1987 and became the modern standard technique. The continuous curved edge stretches rather than tears under surgical forces. With continuous curvilinear capsulorhexis and the use of ophthalmic viscosurgical devices (OVD), IOLs can be intentionally placed within the capsule, dramatically reducing postoperative IOL decentration.
Creating an appropriate continuous curvilinear capsulorhexis is directly linked to postoperative IOL stability. A precise, round capsulorhexis that is smaller than the IOL optic provides the foundation for secure IOL fixation within the capsular bag. Especially in cases with premium IOLs such as multifocal or toric lenses, the accuracy of the capsulorhexis becomes even more critical to maximize IOL centration 2).
QWhat is the purpose of creating a continuous curvilinear capsulorhexis?
A
To create a circular opening in the anterior lens capsule, preparing the foundation for subsequent phacoemulsification and IOL insertion. A round, appropriately sized continuous capsulorhexis that evenly covers the IOL optic contributes to long-term IOL stability and helps prevent posterior capsule opacification.
2. Main Techniques for Creating a Continuous Curvilinear Capsulorhexis
The turnover method involves inverting the anterior capsule so that the edge of the continuous curvilinear capsulorhexis follows the circumference.
Inject OVD into the anterior chamber to flatten the anterior capsule.
Pierce the center of the anterior capsule with the tip of a cystotome or forceps and create a curved slit (approximately 50-70% of the planned CCC radius).
Grasp the anterior capsule flap and push it upward and forward to advance the tear.
The closer the grasping point of the flap is to the leading edge, the more directly the tear follows the direction of traction.
Complete the continuous curvilinear capsulorhexis by regrasping the flap every 1/4 to 1/3 of the circumference.
Once the tear has completed a full circle, redirect it from the outside inward to meet the original line.
The bimanual continuous curvilinear capsulorhexis technique was reported by Taniguchi et al. in 1989 (IOL, 3: 82-87). It was developed to overcome the difficulty of operating near the wound with the conventional one-hand method.
In this technique, a 23-gauge infusion needle held in the right hand creates the left half of the continuous curvilinear capsulorhexis, and a 27-gauge non-infusion needle held in the left hand creates the right half. By using irrigation fluid instead of OVD for anterior chamber formation, the anterior capsule flap floats upward during capsulorhexis creation, improving visibility.
Can-Vac CCC is a technique that uses a 25-gauge blunt cannula and vacuum suction from a 5 ml syringe. The main feature is that the capsule flap is grasped and manipulated by negative pressure generated by the syringe plunger, and its primary advantage is application in difficult cases with high intracapsular pressure, such as intumescent cataract.
The procedure steps are as follows:
Make an incision in the anterior capsule with a 26-gauge needle cystotome and lift a small flap.
Insert a 25-gauge cannula into the anterior chamber through a side port.
Manually pull the syringe plunger to grasp the free edge of the flap with negative pressure.
While adjusting suction pressure, repeatedly grasp and regrasp the flap to complete the continuous curvilinear capsulorhexis in a circular motion.
In intumescent cataract, the milky liquefied cortex released during manipulation can be aspirated with the cannula while simultaneously grasping the flap, allowing completion of the capsulorhexis in one step without instrument exchange or reinjection of viscoelastic material. The 25-gauge diameter provides the minimal suction opening to reliably grasp the flap while preventing excessive aspiration of viscoelastic material or flap tearing.
This is a low-cost technique that can be performed by simply adding a cannula to standard cataract surgery instruments, but there is a learning curve, so it is advisable to first gain proficiency in routine cases before considering application in difficult cases.
Ideal Size of Continuous Curvilinear Capsulorhexis
The diameter of the central zonular-free zone, where no zonules attach to the anterior capsule surface, is approximately 6.9 mm. A capsulorhexis of 7 mm or more is likely to damage the zonules. The ideal capsulorhexis size is 5 to 5.5 mm, which is round, smaller than the IOL optic, and covers the IOL optic. For a 6.0 mm IOL, the goal is to create a 5.0 to 5.2 mm opening to achieve optimal overlap.
QWhat to do if the capsulorhexis is too small?
A
If the capsulorhexis is too small, anterior capsule contraction is more likely, especially in cases with exfoliation syndrome or zonular weakness. Severe contraction can cause the capsulorhexis edge to cover the IOL optic, leading to visual impairment. After IOL insertion, make cuts in the capsulorhexis edge and use anterior capsule forceps to correct it using the IOL optic edge as a guide. Additionally, a too-small capsulorhexis may cause anterior capsule tears or zonular rupture during phacoemulsification.
3. Difficult Cases and Anterior Capsule Visualization
When the red reflex is diminished (e.g., mature cataract, white cataract, corneal opacity), using a staining agent such as trypan blue improves visualization of the anterior capsule. The most common method is to inject trypan blue under an air bubble and then wash out the excess dye.
In continuous curvilinear capsulorhexis for white cataract, important factors include ensuring visualization with anterior capsule staining, maintaining anterior chamber depth with a high-molecular-weight, high-concentration OVD (e.g., Healon V®, a viscous dispersive type), removing liquefied cortex, and selecting appropriate forceps and scissors inserted through a side port.
Problems with manual continuous curvilinear capsulorhexis include: (1) difficulty in consistently creating a perfect circle, (2) tendency for decentration or deformation, and (3) susceptibility to being misled by pupil size regarding the capsulorhexis diameter. To overcome these issues, the following devices have been developed.
FSLC (Femtosecond Laser)
Features: With laser settings, a perfectly round continuous curvilinear capsulotomy can be created at the intended diameter and position. This enables the most accurate capsulotomy. It is based on the mechanism by which a pulsed laser photodisrupts the anterior capsule tissue.
Advantages: Reduces the risk of anterior capsule tears in white cataracts compared to manual continuous curvilinear capsulotomy. In cases of lens dislocation with soft nuclei, it has been reported that the lens capsule can be preserved in 90% of cases. A 2020 meta-analysis (73 studies, FLACS 12,769 eyes vs. conventional method 12,274 eyes) showed significant improvement in capsulotomy circularity and reduction in cumulative dissipated energy (CDE)5). According to ESCRS guidelines, both FLACS and continuous curvilinear capsulotomy are safe and effective, with equivalent postoperative visual and refractive outcomes4).
Limitations: The equipment is large and costly. Cases with corneal opacity or poor pupil dilation (dilated pupil diameter approximately 5.0 mm or less) are not indicated. Reduction in posterior capsule rupture or corneal endothelial cell loss has not been consistently demonstrated5). Complications specific to FLACS include incomplete capsulotomy and anterior capsule tags, where residual small fragments at the capsular edge can become starting points for radial tears.
PPC (Zepto®)
Features: A disposable device that received FDA approval in 2017. It consists of a thin transparent silicone suction shell, a flexible nitinol thermal electric ring, and a small console. After the suction shell is attached 360 degrees to the anterior capsule, a rapid energy pulse of less than 5 ms instantly creates a circular capsulotomy approximately 5.2 mm in diameter. It was approved for insurance coverage in Japan in 2019.
Advantages: Simple operation and automatic creation of a perfectly round capsulotomy. The edge of the capsulotomy is everted, making it stronger under tension than continuous curvilinear capsulotomy or FSLC. Useful in cases with mild corneal opacity or mature cataracts. Centration on the visual axis using the Purkinje reflex is possible, and improved IOL centration accuracy is expected in cases using multifocal or toric IOLs. Compared to FLACS, advantages include no need for additional space, lower cost, and seamless integration into the normal workflow.
Limitations: Shallow anterior chamber cases are not indicated due to the risk of corneal endothelial contact. There is a learning curve because the procedure differs from standard continuous curvilinear capsulotomy.
CAPSULaser
Features: A device that can be attached as a mobile attachment to a surgical microscope (EXCEL-LENS Inc.). It delivers continuous thermal energy to the anterior capsule stained with trypan blue, creating a circular capsulotomy in one second via selective photothermal lysis. The diameter can be easily adjusted from 4.5 to 7 mm.
Histological findings: The cutting edge of the CAPSULaser shows a thermal denaturation effect (cauterized margin) that bends slightly forward. A phase change with roll formation occurs at the capsular edge, and it is said to provide more stable edge strength than manual continuous curvilinear capsulorhexis or FLACS. The thermal denaturation zone measures 62.12 μm in width, and transmission electron microscopy (TEM) shows a fragmented, bulbous appearance of the edge. This is due to a different mechanism from the multiple pulse energy applications of FLACS2).
Difference from continuous curvilinear capsulorhexis edge: The cutting edge of manual continuous curvilinear capsulorhexis is sharp, tapering from front to back, and TEM shows a clear, angular edge2).
Aperture CTC
Features: Aperture Continuous Thermal Capsulotomy (CTC) is a preclinical device (International Biomedical Devices). It delivers thermal energy through a ring-shaped steel cutting element in 360-degree contact with the anterior capsule, melting collagen to create an anterior capsulotomy. Designed for efficiency, it features easy integration into the normal surgical workflow.
Creates a 5.5 mm diameter indentation directly on the anterior lens capsule from inside the eye. Unaffected by anterior chamber depth. Viscous dispersive OVD is optimal
Cases where avoiding the influence of anterior chamber depth is desired
Image guidance system
Projects a ring into the surgical microscope
Examples of preoperative data utilization
Anterior Capsulotomy and Posterior Capsule Opacification
When the anterior capsulotomy completely covers the IOL optic for 360 degrees, migration of lens epithelial cells to the posterior capsule is suppressed in some IOL designs, reducing the formation of posterior capsule opacification (PCO) 3). If the anterior capsulotomy diameter is less than 4 mm or greater than 6 mm, coverage becomes incomplete and PCO risk increases. Automated devices have the advantage of consistently achieving this appropriate size, but there is currently insufficient evidence that automation significantly reduces PCO compared to manual techniques.
5. Complications and Management During Continuous Curvilinear Capsulorhexis
During continuous curvilinear capsulorhexis, if posterior pressure is applied, the tear may extend radially toward the lens equator (run-out).
Management steps:
Prompt detection is key: If the tear appears to extend, stop and immediately add OVD to the anterior chamber to relieve posterior pressure.
Redirect using the Little technique: Grasp the capsular flap and apply traction in the opposite direction on the same plane to redirect the flap toward the center.
Complete capsulorhexis from the opposite side: If redirection is not possible, complete the capsulorhexis from the opposite side or cut the edge with intraocular scissors.
New incision from the opposite side: If the tear extends to the equator and the incision line is not visible at the pupillary margin, create a new incision from the opposite side and connect.
If the tear extends toward the equator and cannot be captured promptly, it may continue to spread radially posteriorly, potentially leading to nucleus drop or vitreous loss.
Tears in the continuous curvilinear capsulorhexis edge can occur due to a notch at the capsulorhexis junction, accidental puncture of the anterior capsule during side-port creation, or subluxation of a large nucleus into the anterior chamber through a small capsulorhexis.
If a tear occurs, there is a risk of extension to the posterior capsule, so extreme caution is needed during phacoemulsification and IOL insertion. When injecting the IOL with an injector, ensure that the tip of the haptic does not directly press the equator at the tear site, and insert the haptic into the capsular bag in a direction perpendicular to the tear.
The corner of the flap at the tear edge may roll up and cause adhesion to the iris, leading to pupil deformation or poor dilation. It is recommended to smooth the corner using an irrigation/aspiration (I/A) tip.
QWhat is the first step when the continuous curvilinear capsulorhexis starts to run toward the equator?
A
The most important first step is to add OVD into the anterior chamber to relieve posterior pressure. After relieving posterior pressure, promptly redirect the flap toward the center using the Little technique. Delayed detection can lead to serious complications such as nucleus drop or vitreous prolapse.
The decrease in corneal endothelial cell density (ECD) after cataract surgery is thought to be mainly due to the energy and fluid turbulence from phacoemulsification, rather than the method of anterior capsulotomy (CCC vs PPC)1).
Vital et al. (2023) conducted a prospective randomized multicenter trial involving 67 patients (33 in the CCC group, 34 in the PPC group). They found that the ECD reduction rate at 1 month postoperatively was 11.5% in the continuous curvilinear capsulorhexis group and 12.3% in the PPC group (P=0.818), and at 3 months it was 11.7% and 12.4% respectively (P=0.815), showing no significant difference between the two groups1).
At 3 months postoperatively, the upper limit of the 95% CI for the PPC group was below the non-inferiority delta of 7%, demonstrating that PPC has equivalent corneal endothelial cell safety to continuous curvilinear capsulorhexis1).
Corneal endothelial cells naturally decrease with age, from about 4000 cells/mm² in childhood to approximately 2250–2500 cells/mm² in the 80s. When ECD drops to 600–800 cells/mm², corneal endothelial dysfunction such as corneal edema or opacity may occur, potentially requiring surgical intervention like corneal transplantation1).
Additionally, there is a linear relationship between cumulative dissipated energy (CDE) and ECD reduction rate; each unit increase in CDE is associated with approximately a 1.6% increase in ECD reduction rate at 1 month postoperatively1).
Morphological changes in corneal endothelial cells
As ECD decreases, the percentage of hexagonal cells (%Hex) decreases and the coefficient of variation (CV) of cell size increases. In both the continuous curvilinear capsulorhexis and PPC groups, the preoperative %Hex of about 58% decreased to approximately 54–56% at 3 months postoperatively, with no significant difference between the groups1).
QDoes the method of anterior capsulotomy (CCC vs. PPC) affect corneal endothelial cells differently?
A
In a randomized controlled trial by Vital et al. (2023), the ECD reduction rate, percentage of hexagonal cells, and coefficient of variation of cell size at 1 and 3 months postoperatively showed no statistically significant differences between the continuous curvilinear capsulorhexis group and the PPC group 1). The energy used for phacoemulsification (CDE) is considered the main factor in corneal endothelial cell damage, rather than the capsulotomy method itself.
7. Latest Research and Future Perspectives (Investigational Reports)
Pothikamjorn et al. (2025) published a case report comparing CAPSULaser and continuous curvilinear capsulorhexis in both eyes of the same patient. The maximum lens cortical collagen fiber thickness of the anterior capsule after CAPSULaser was measured at 237.1 μm, showing a structure with extensive tissue incorporation. In contrast, the continuous curvilinear capsulorhexis specimen did not contain lens cortical collagen fibers and consisted only of the anterior capsule and cuboidal epithelial cells 2).
The tendency of the CAPSULaser incision edge to bend anteriorly is attributed to collagen phase change improving tissue elasticity. This characteristic suggests that CAPSULaser may be advantageous in cases with complex anterior capsule pathology such as anterior capsule fibrosis 2). However, confirmation through large-scale studies is needed.
Vital MC, Jong KY, Trinh CE, Starck T, Sretavan D. Endothelial Cell Loss Following Cataract Surgery Using Continuous Curvilinear Capsulorhexis or Precision Pulse Capsulotomy. Clin Ophthalmol. 2023;17:1701-1708. doi:10.2147/OPTH.S411454
Pothikamjorn T, Prasanpanich M, Somkijrungroj T. Comparative evaluation of anterior lens capsule electron microscopic pathology in a case undergoing simultaneous bilateral cataract surgery: A study of CAPSULaser and continuous curvilinear capsulorhexis. Am J Ophthalmol Case Rep. 2025;39:102400. doi:10.1016/j.ajoc.2025.102400
American Academy of Ophthalmology. Cataract in the Adult Eye Preferred Practice Pattern. Ophthalmology. 2022;129(1):P1-P126.
Kolb CM, Shajari M, Mathys L, Herrmann E, Petermann K, Mayer WJ, et al. Comparison of femtosecond laser-assisted cataract surgery and conventional cataract surgery: a meta-analysis and systematic review. J Cataract Refract Surg. 2020;46(8):1075-1085. doi:10.1097/j.jcrs.0000000000000228.
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