Peripheral capsulorhexis – A novel technique to prevent Argentinian flag sign in intumescent white cataracts

Abstract

The most challenging step in handling an intumescent cataract is the creation of a well-sized, round, centered, continuous, and curvilinear capsulorhexis. Due to high intralenticular pressure, the capsulorhexis tear has high tendency to extend equatorially leading to development of Argentinian flag sign. To overcome this, we describe a novel technique of capsulorhexis for intumescent white cataracts that does not need special instrumentation. Antero-posterior diameter of lens is more in the center due to its biconvex configuration. This leads to more intralenticular fluid accumulation and thus comparatively higher intralenticular pressure in the center. Thus, it was decided not to touch central, tense, bulging capsule, and initiate capsulorhexis in the periphery. Two perimetric flaps were created, sheared circumferentially, and joined midway resulting in a complete circular capsulorhexis. This minimized the tendency of capsulorhexis runway to the periphery and allowed one-stage creation of a well-sized capsular opening for phacoemulsification.

In the literature, there is no standard definition for intumescent cataracts. Centurion et al. describe it as a cataract thicker than 5.5 mm with an AC angle smaller than 45° and an anterior chamber depth (ACD) less than or equal to 2.2 mm. On the other hand, Brazitikos et al.[1] defined it as a cataract with a flocculent cortex and high internal reflections on ultrasound A-scan.

Phacoemulsification in cases of intumescent white cataracts poses a significant challenge to surgeons. Nevertheless, they prefer phacoemulsification for these cataracts because it enables smaller incisions and offers several advantages, such as rapid wound healing, reduced surgically induced astigmatism, and decreased likelihood of postoperative infections.

The primary challenge in surgically managing an intumescent cataract is achieving a properly sized continuous curvilinear capsulorhexis (CCC). This method is preferred over alternatives like the can-opener capsulotomy, which are linked to higher complication rates. Some of these complications include anterior capsular radial tears, which can destabilize the capsular bag. Other risks include posterior capsular tears, vitreous prolapse, and intraocular lens (IOL) instability.[2]

Various methods have been described to improve and facilitate an easy capsulorhexis in intumescent white cataracts. These include the use of cohesive viscoelastics, trypan blue dye, puncturing the anterior capsule with positive pressure in the anterior chamber, utilizing a two-stage capsulorhexis,[3] performing an insulin needle-assisted capsular perforation and fluid removal,[4] using utrata forceps-assisted capsulorhexis, Puncho rhexis/Phaco capsulotomy,[5] sewing needle microcapsulotomy,[6] capsule milking,[7] femtosecond laser-assisted capsulorhexis,[8] nanosecond pulse capsulotomy,[9] and capsule laser. Despite these methods, there remains a risk of creating an “Argentinian flag sign.”

The Argentinian flag sign is a well-known complication that can occur during capsulorhexis in intumescent white cataracts. It was first described by Daniel Mario Perrone, MD.[10] Perrone enumerated the findings, secondary consequences, and additional preventive measures associated with this phenomenon. According to the literature, the incidence of the Argentinian flag sign ranges from 3.85% to 28.3%. This sign is characterized by a radial anterior capsular tear that occurs during capsulotomy through trypan blue-stained anterior lens capsules. Once the tear propagates equatorially, it leaves behind a light blue torn anterior capsule with a central white cataract emerging from the capsule.

During capsulotomy, when the anterior intralenticular pressure (ILP) dissipates into the anterior chamber, a pressure difference is created by the residual posterior ILP. This pressure difference causes the lens to shift anteriorly, putting strain on the capsule. Several factors, such as poor chamber maintenance with viscoelastic or excessive posterior pressure, as observed during patient exertion during valsalva, are likely to contribute to this complication.

Surgical Technique

Topical moxifloxacin 0.5% eye drop was used 3 days before the surgery. Preoperative cleaning of the conjunctival sac was performed with povidone-iodine 5%, and full asepsis was maintained. The temporal site was used for performing routine phacoemulsification surgery. Then, 0.8 mm incision side ports were made using a side port knife at 1:30 o’clock and 4:30 o’clock. Anterior capsule staining using trypan blue 0.06% was performed under air. The dye was washed with an irrigating solution. The OVD like sodium hyaluronate (1.4% Healon GV) was injected in an amount sufficient to pressurize the chamber properly. A temporal self-sealing clear corneal incision as a main port was made using a 2.8 mm keratome blade. A 26 gauge needle was bent at the junction of peripheral one-third and central two-thirds [Fig. 1a and b]. Initial puncture with this bent 26 No. needle was performed through main port incision at the junction of the peripheral one-third and central two-thirds of the anterior capsule. The needle was moved toward center in subcapsular space, and aspiration of fluid was performed to reduce intralenticular pressure centrally. [Fig. 2] The anterior chamber was refilled with dispersive viscoelastic (2% HPMC). Radial nick about 0.2 mm in size toward the center was made with microrhexis scissors. [Fig. 3] Now, two circumferential flaps were visible. [Fig. 4] Anterior chamber was again refilled with viscoelastic. Through the two side ports, microrhexis forceps were introduced, and circumferential flaps were grasped and rotated circumferentially to 90° [Fig. 5a and b]. Two flaps were rotated till complete circular capsulorhexis was achieved [Fig. 6]. The technique of “peripheral capsulorhexis” is shown in video clip 1. In intumescent white cataracts, hydrodissection is generally not required. Nuclear fragmentation was performed with suitable chopping technique, and phacoemulsification was performed followed by foldable IOL implantation in the capsular bag.

Figure 1.

(a and b) 26 No. needle bent at junction of peripheral one-third and central two-thirds with bevel downwards

Figure 2.

Puncture of anterior capsule done at junction of peripheral one-third and central two-thirds with aspiration of central subcapsular fluid. (yellow arrow)

Figure 3.

Linear radial cut 0.2 mm in size made through the initial puncture. (yellow arrow)

Figure 4.

Two peripheral flaps visible.(red arrow)

Figure 5.

(a and b) First and second peripheral flaps grasped with microrhexis forceps and rotated circumferentially. (red arrows)

Figure 6.

Circular curvilinear capsulorhexis completed. (dotted black circle)

Results

This novel technique has been used in 52 intumescent white cataracts during the period of January 2023 to January 2024. All surgeries were performed by a single surgeon in a single surgical setup. It was observed that capsulorhexis was completed in 51 patients (98.07%), while in one patient (1.92%), splitting and widening of anterior capsule opening were noted becausethe initial nick was too peripheral and it was not at the junction of peripheral one-third and central two-thirds of anterior capsule. This capsulorhexis extension was later fashioned into an almost circular capsulorhexis gently with the help of microrhexis scissors and forceps.

Discussion

Capsulorhexis is a crucial step in cataract surgery. Failure to create an intact anterior capsule opening can lead to a posterior extension beyond the equator, which may cause complications such as zonule rupture, vitreous loss, a dropped nucleus, and posterior displacement of the IOL.[11,12]

The Argentinian flag sign can complicate surgery for intumescent white cataracts during the early stages of the procedure. To prevent this complication, it is widely recommended to decompress the capsular bag by pricking it with a 26-gauge or 30-gauge sharp hypodermic needle, followed by aspiration of the liquefied lens matter. This recommendation is based on the known fact that raised intralenticular pressure, leading to forward nuclear thrust, is solely responsible for the splitting of the anterior capsule.

The technique that uses the phaco needle tip to “punch” a hole through the anterior capsule to create an intact capsulotomy is less reproducible. Also, in eyes with phacomorphic glaucoma where the anterior chamber is extremely shallow, this technique can be challenging, particularly when the cornea becomes hazy due to increased intraocular pressure during the CCC procedure.[13]

Although the use of femtolaser technology³³ has created an effective tool that helps to create a perfect capsulotomy, the technology adds to the cost of cataract surgery. Eyes with intumescent cataracts are more commonly encountered in developing countries, which are less able to afford these new technologies.[14]

Sewing needle microcapsulotomy creates an opening in the anterior capsule with a round regular configuration with the help of sewing needle microcapsulotome, but in our view, making a hole over anterior tense capsule with high intralenticular pressure may create a radial equatorial extension of capsulorhexis, and this procedure needs an instrument which is not readily available in all setups.

In our novel capsulorhexis technique, a temporal self-sealing clear corneal incision was created as the main port using a 2.8 mm keratome blade. A 26-gauge needle was then bent at the junction of its peripheral one-third and central two-thirds. The initial puncture with this bent needle was made through the main port incision at the junction of the peripheral one-third and central two-thirds of the anterior capsule. The needle was directed toward the center in subcapsular space, and fluid was aspirated to reduce central intralenticular pressure. The anterior chamber was filled with dispersive viscoelastic (2% HPMC). A small radial nick, about 0.2 mm in size, was made toward the center using microrhexis scissors, resulting in two circumferential cuts which were then fashioned into two circumferential flaps. The anterior chamber was refilled with viscoelastic, and microrhexis forceps were introduced through the side ports to grasp and rotate the circumferential flaps 90°. The flaps were rotated until a complete circular capsulorhexis was achieved.

Conclusion

Peripheral capsulorhexis technique for intumescent cataracts is a successful and reproducible method of achieving a well-sized capsulorhexis without the risk of equatorial extension. In intumescent white cataracts anterior capsule tends to be stretched and tense in the center, so a technique that avoids the central vulnerable part of the anterior capsule and involves making peripheral capsulorhexis can prevent the dreaded Argentinian flag sign.

What was known

• Raised intralenticular pressure, which causes the nucleus to thrust forward, is solely responsible for the extension of the tear to the periphery. To counter this, a small needle aspiration technique in the center has been described.

• Creating a capsulorhexis in an intumescent cataract carries a high risk of capsulorhexis extension.

• The tendency of the capsulorhexis to extend can be minimized by pressurizing the anterior chamber, decompressing the capsular bag, and creating a small capsulotomy, which can be enlarged at a later stage.

What this paper adds

• Biconvex shape & high intralenticular pressure at centre of swollen lens causes maximum tension and stretching at the centre of the capsule, so we decided to avoid touching the centre. Instead, we initiated the capsulorhexis from the periphery.

• No special instrumentation, equipment, or high-end technology is required, and there is a minimal learning curve.

• We describe a novel technique of peripheral CCC that is reproducible and safe.

Conflicts of interest:

There are no conflicts of interest.

Funding Statement

Nil.