Phaco capsulotomy: a technique to prevent the Argentinean Flag Sign

Drug delivery from a ring implant attached to intraocular lens: An in-silico investigation

Multiple iterations required to design ocular implants, which will last for the desired operational period of months or even years, necessitate the use of in-silico models for ocular drug delivery. In this study, we developed an in-silico model to simulate the flow of Aqueous Humor (AH) and drug delivery from an implant to the Trabecular Meshwork (TM). The implant, attached to the side of the intraocular lens (IOL), and the TM are treated as porous media, with their effects on AH flow accounted for using the Darcy equation. This model accurately predicts the physiological values of Intraocular Pressure (IOP) for both healthy individuals and glaucoma patients, as reported in the literature. Results reveal that the effective diffusivity of the drug within the implant is the critical parameter that can alter the bioavailability time period (BTP) from a few days to months. Intuitively, BTP should increase as effective diffusivity decreases. However, we discovered that with lower levels of initial drug loading, BTP declines when effective diffusivity falls below a specific threshold. Our findings further reveal that, while AH flow has a minimal effect on the drug release profile at the implant site, it significantly impacts drug availability at the TM.

Star Can Vac Capsulorhexis in White Total Cataracts - A Retrospective Interventional Analysis

Aim

Completing circular uniform anterior capsulorhexis in intumescent white cataracts is challenging for all cataract surgeons. Numerous techniques have been described to get a circular capsulorhexis and prevent perpendicular linear tears in the anterior capsule.

Methods

570 cases of white total cataracts were selected for this retrospective clinical study. In this technique of Star CanVac rhexis, the anterior lens capsule was nicked using a 26 G cystotome, and multiple centripetal tears were made in the center to create a small star-shaped opening. A vacuum was used to develop capsulorhexis, and a 25 G flat tip cannula attached to a 5 ml syringe half filled with balanced salt solution (BSS) was used to build capsulorhexis. The piston of the 5 ml syringe was withdrawn to create a vacuum to hold the free capsular flap. It was then directed circularly to get a round capsulorhexis. Oozing liquefied cortex was aspirated simultaneously with the same cannula.

Results

This technique was successfully executed in 564 eyes. Six eyes had anterior capsular tears, 2 of which extended into the posterior capsule.

Discussion

Intumescent cataracts often complicate the rhexis procedure due to increased lens volume and pressure. Over time, different methods have been refined to handle the pressure variation between the anterior chamber and the intralenticular area, such as mini-rhexis, double rhexis, sewing needle capsulotomy, and phaco capsulotomy. The primary goal of these procedures is to first reduce the elevated intralenticular pressure. Star CanVac capsulotomy facilitates equal pressure between the anterior chamber and the lenticular compartment, effectively reducing the risk of accidental capsular tears. Advantages of this approach include completing rhexis in one step, removing the liquefied cortex simultaneously, and relying on easily accessible instruments.

Conclusion

Star CanVac capsulorhexis is an effective, safe, and alternative technique to conventional capsulorhexis in total white cataracts.

Midperipheral mini-capsulorhexis as an additional step for safe phacoemulsification in white intumescent cataracts

The present article describes a novel surgical technique of a primary mini-capsulorhexis in midperiphery to minimize surgical complications in white intumescent cataracts. Patients with white mature cataracts with a convex anterior capsule or swollen lens fibers were selected. An initial puncture was made 3-4 mm away from the center, in the midperipheral anterior capsule, with a conventional cystitome. A mini-capsulorhexis (2-2.5 mm) was created. Loose cortical matter and fluidic contents were aspirated to reduce the intralenticular pressure. Two cuts were made at the margin of the mini-capsulorhexis, and an adequately sized secondary rhexis was completed, after which phacoemulsification was done. A circular curvilinear capsulorhexis was successfully achieved in all cases, including those with a small pupil. Rhexis could be completed in a patient where an initial extension occurred due to head movement. This refined technique aims to enhance the safety and precision of capsulorhexis in intumescent cataracts, thereby reducing the risk of complications such as the Argentinian flag sign. Further exploration and validation of this approach through clinical trials are warranted to establish its efficacy and safety profile.

Automated Capsular Decompression to Avoid Argentinian Flag Sign in Intumescent Cataract

Purpose

We describe an alternative automated technique that consists of simultaneous anterior capsule puncture and decompression of the capsular bag by using an insulin needle attached to the aspiration tubing of the phacoemulsification device to prevent the occurrence of the "Argentinian Flag sign" during capsulorhexis in intumescent cataract.

Setting

Instituto de Olhos de Assis and Center of Specialties Hoftalmed, located in the state of São Paulo, Brazil.

Design

Prospective interventional study.

Methods

Eighty-eight eyes of 88 patients with white or intumescent cataracts were included in this study. Routine clear cornea incision, capsule staining with trypan blue, intracameral anesthesia, and ophthalmic viscoelastic device were used before the procedure. A 26-gauge needle was connected to the phacoemulsification aspiration tubing using a double male Luer connector for irrigation, and aspiration was inserted into the anterior chamber through a new paracentesis incision with the bevel facing down. Immediately after insertion, automated aspiration of the liquefied cortex was performed to remove anterior intralenticular material and achieve capsular decompression. Compression of the nucleus with the needle tip was performed to remove any liquefied material trapped between the posterior surface of the nucleus and the posterior capsule. All surgeries were performed using the same phacoemulsification and parameters. The rate of complete continuous capsulorhexis was observed and noted.

Results

No complications were observed in any of the cases. A single-stage, continuous, and well-centered capsulorhexis was achieved in 100% of cases.

Conclusion

We conclude that a simultaneous puncture and decompression of the capsular bag using an insulin needle attached to the aspiration tubing of the phacoemulsification machine effectively avoided the "Argentinian Flag sign" in intumescent cataract surgery.

Double peak sign on ultrasonography: A new prognostic marker before surgery for white cataract

A mature, hypermature, or white cataract needs posterior segment evaluation before surgery for prognostification. Ultrasonography is the preferred method for this. White cataract or intumescent cataract risks intraoperative capsulorhexis running out leading to devastating complications due to high intralenticular pressure. Altghough sligh-lamp examination before surgery can gives clue regarding fluid pockets under anterior capsule in these types of cataract, fluid in posterior compartment of lens can be detected by ultrasonography. The author here described a new sign, the double peak sign which can predict the high intra-lenticular pressure especially in posterior compartment of the lens. So if it detected before surgery, all precautions can be taken during surgery to prevent complications. The A-scan overlay on the B-scan in ultrasonography can detect the hypoechoic area corresponding to the lequified cortex in between solid lens nucleus and posterior capsule, so giving rise to the double peak sign which is described here as an innovation.

Preventing the Argentinian flag sign and managing anterior capsular tears: A review

The Argentinian flag sign (AFS) is a feared complication during cataract extraction. Intralenticular pressures, especially excessive posterior pressure, have been identified as potential mechanisms for capsular stress and tearing associated with AFS. Capsular tension is created by positive intralenticular pressures, which cause the irido-lens diaphragm to move anteriorly once the manual capsulorhexis has been initiated. This tension can cause inadvertent tears that self-propagate to the lens equator, causing an AFS, among other intraoperative complications. Thus, this review highlights the importance of identifying intumescent cataracts as well as a combination of techniques to relieve intracapsular pressures needed to prevent AFS. However, some instances of anterior capsular tears are unavoidable. Therefore, focus will also be placed on techniques during cataract extraction used to manage anterior capsular tears, mitigating extension to the posterior capsule.

Flow capsulorhexis: A novel technique in white and hypermature cataracts

We described a novel "flow capsulorhexis" technique in white and hypermature cataracts and compared it with the standard "needle decompression capsulorhexis" technique. Six hundred and eight eyes of 420 patients with intumescent or non-intumescent mature white cataracts who had undergone phacoemulsification or manual small incision cataract surgery with "flow capsulorhexis" (Group 1) or "needle decompression capsulorhexis" (Group 2) were assessed. The mean continuous curvilinear capsulorhexis (CCC) completion time was 6.6 ± 3.4 seconds in Group 1 and 10.4 ± 4.2 seconds in Group 2 (P < 0.001). The mean number of times for an ophthalmic viscosurgical device (OVD) supplement was 0.4 ± 0.2 and 1.8 ± 0.8 in Group 1 and Group 2, respectively (P < 0.001). CCC success rate was 95.8% in Group 1 and 87.2% in Group 2 (P = 0.001). The new technique was observed to have better outcomes in terms of surgical time, OVD supplement times, and success rate than the standard needle decompression technique.

Argentinian flag sign during refractive laser-assisted cataract surgery - A case report

Purpose

The Argentinian flag sign, or radial capsular tear extensions, is a rare complication when performing capsulorhexis during cataract surgery. Identifying and managing this complication early is important to prevent the tear from propagating around the periphery leading to posterior capsular rupture or vitreous loss.

Observations

The Argentinian flag sign was previously reported in a case of femtosecond laser-assisted cataract surgery (FLACS). However, our report presents the first case after FLACS using the Catalys™ Precision Laser System, a platform which has been associated with a larger percentage of complete capsulotomies when compared to other platforms. Radial extensions of the capsular tear were observed in a 27-year-old male patient with an intumescent cataract in left eye. The complication was managed by manually redirecting and completing the radial extension flaps, along with delicate phacoemulsification and manual cutting of capsular edge in areas with significant capsular-IOL overlap.

Conclusions and importance

Our case report highlights that despite the Catalys™ Precision Laser System success rates, radial tears may occur, especially in highly pressurized intumescent cataract. Therefore, surgeons must be prepared to optimize the surgical techniques to prevent the occurrence of this complication, as well as identify and manage it when it presents.

Vacuum rhexis - A novel capsulorhexis technique for white cataracts

Capsulorhexis in white intumescent cataract is often associated with extension leading to radial tears or biradial extension "Argentinian flag sign" and associated complications. We describe a novel technique of managing this situation. Vacuum rhexis is performed with a 24 G bent cannula attached to a 10-ml syringe. The flap is lifted and then caught using 24 G cannula. The suction is manually controlled by the surgeon, and the rhexis is completed using circumferential movement. The chamber stability is well maintained as there is no leakage, and the bent tip gives excellent fulcrum for movement. The advantage of this technique is that a single port is used for maintaining the chamber stability and it needs no special surgical instruments. Vacuum rhexis is a novel surgical technique used for performing successful continuous curvilinear capsulorhexis (CCC) of adequate size in white and intumescent cataracts, with a consistent and predictable outcome.

Modified capsulorhexis for fiuid-filled mature cataracts

Background

The aim of this study was to develop a modified capsulorhexis technique featuring a new maneuver for the removal of subcortical fluid in fluid-filled mature cataracts to avoid high intralenticular pressure.

Methods

This prospective interventional study included 33 eyes with mature cataracts and evidence of subcapsular fluid spaces by slit lamp examination. For each patient, 20% mannitol was administered intravenously according to the bodyweight 1 h preoperatively. Under peribulbar anesthesia, a 2.2-mm main incision was made, and the anterior chamber was filled with a dispersive ophthalmic viscosurgical device. Using a bent-tip cystotome, a 2-mm curved incision was made in the center of the anterior capsule, which released subcortical fluid and was drained through compression of the posterior lip of the main incision using a spatula. Then, fine gentle milking in all quadrants around the puncture on the anterior lens capsule from the periphery toward the site of puncture using the blunt-edged spatula further assists drainage of subcortical fluid and breaks fine septa inside the lens to remove fluid from intralenticular fluid pocket collections.

Results

The study included 15 (45.5%) men and 18 (54.5%) women with a mean (standard deviation [SD]) of age of 63.2 (5.33) and 64.4 (6.21) years, respectively. The modified capsulorhexis technique was performed for 33 intumescent cataracts. Capsulorhexis was completed in all cases; capsulorhexis was easy in 31 (94%) eyes and difficult in 2 (6%) eyes. In the two difficult cases, radial extension occurred in one eye, and it was retrieved using the Little technique; the other case with radial tear was completed successfully using a retinal micro scissor from the other edge of the capsulorhexis until reaching an oval, continuous capsulorhexis.

Conclusions

This modified capsulorhexis technique with compression on the posterior lip of the main incision and capsule milking allowed for a safe, continuous curvilinear capsulorhexis. Further comparative studies are necessary to confirm our preliminary results.

Argentinian Flag Sign and Its Management during Femtosecond Laser-Assisted Cataract Surgery in a Case with Intumescent Cataracts

We describe a case of radial extension and its management during femtosecond laser-assisted cataract surgery (FLACS) in a patient with intumescent cataracts. Radial extension was observed after injection of trypan blue into the anterior chamber. Management of the extension was achieved by separation of adhesions between the incomplete capsulotomy, along with manual completion at the areas of extensions. Careful observation during FLACS capsulotomy is advised in cases of intumescent cataracts due to the release of cortex into the anterior chamber which may interfere with the delivery of the laser treatment resulting in incomplete capsulotomy patterns. Furthermore, trypan blue staining is essential to identify possible incomplete capsulotomy patterns and extensions. The Argentinian flag sign may occur after femtosecond laser-assisted capsulotomy in cases of intumescent cataracts. Proper identification of incomplete capsulotomy patterns and radial extensions should be managed with careful manual completion of the capsulotomy.

Femtosecond laser-assisted cataract surgery in shallow anterior chamber cases

PURPOSE

To assess the effectiveness, safety and predictability of femtosecond laser-assisted cataract surgery (FLACS) in eyes with shallow anterior chamber (AC).

METHODS

This is a prospective consecutive clinical study. All eyes presented an anterior chamber depth (ACD) ≤ 2.1 mm and were submitted to FLACS with monofocal intraocular lens (mIOL) or trifocal intraocular lens (tIOL) implantation. Uncorrected distance visual acuity (VA) and corrected distance VA values were used to assess efficacy and safety of the surgery. Refraction, intraocular pressure (IOP), endothelial cell density (ECD) and ACD were evaluated before and 6 months post-surgery.

RESULTS

Phacoemulsification was carried out successfully in all eyes, without intra- or postoperative complications. Efficacy and safety indexes were 0.96 and 1.26 for the mIOL group, and 0.87 and 1.01 for the tIOL group, respectively. The mean postoperative spherical equivalent was - 0.06 ± 0.28D and - 0.14 ± 0.38D for the mIOL and tIOL groups, respectively. The ECD varied from 2470 ± 483 to 2009 ± 538 cells/mm² (p < 0.05) and from 2443 ± 319 to 2245 ± 628 cells/mm² (p = 0.06) for the mIOL and tIOL groups, respectively. IOP significantly decreased (p < 0.05) after the surgery from 14.34 to 12.85 mmHg for the mIOL group and from 14.37 to 11.91 mmHg for the tIOL group, with a general reduction of medical hypotensive treatment in both groups (85% of cases required ≤ number of medications). ACD changed significantly (p < 0.05) from 1.96 ± 0.15 mm to 3.75 ± 0.30 mm after the surgery in the mIOL group and from 1.94 ± 0.15 mm to 3.23 ± 0.21 mm for the tIOL group.

CONCLUSION

FLACS with implantation of either mIOL or tIOL may provide good efficacy, safety and predictability in eyes with shallow AC.

Closed-Chamber Anterior Capsulorhexis Under Air Tamponade In White Cataract

Purpose

To evaluate the efficacy and safety of a closed-chamber air bubble capsulotomy technique to prevent the Argentinean flag sign (AFS) in patients with white and intumescent cataracts.

Setting

Sohag University, Faculty of Medicine, Ophthalmology Department, Sohag, Egypt.

Design

Prospective interventional noncomparative case series.

Methods

Eighty-two eyes of 80 patients with white and intumescent cataracts were included. Eyes with any ocular pathology other than cataract or eyes subjected to previous intraocular surgery were excluded. Needle capsulorhexis was performed under a large air bubble tamponade without capsular staining. Efficacy of the technique was assessed intraoperatively by successful completion of capsulorhexis. Safety of the technique was assessed by the occurrence of intraoperative or postoperative complications.

Results

Complete capsulorhexis by the closed-chamber air bubble technique was successful in 75 eyes (91.5%), while capsulorhexis extension occurred in seven eyes. In four eyes with extension, the procedure was shifted to the standard technique of CCC (circular curvilinear capsulorhexis), using a viscoelastic device. A shift to extracapsular cataract extraction (ECCE) surgery occurred in the remaining three eyes, as the extension was so far-gone. No intraoperative or postoperative complications were observed.

Conclusion

The closed anterior chamber air bubble technique for capsulorhexis is a novel, safe, and effective technique to prevent AFS in white and intumescent cataracts. It is also time-saving and cost-effective, with less likelihood of capsulorhexis extension. The technique is considered a valuable addition to previously described techniques.