August 2020

CATARACT

Skill Focus
Under pressure:
Avoiding the Argentinian flag sign


by Liz Hillman Editorial Co-Director


Intumescent white cataract with shallow anterior chamber, bulging anterior capsule, and
subcapsular fluid clefts
Source: Jeewan Singh Titiyal, MD

 

About a year ago, Rosa Braga-Mele, MD, was teaching a resident how to avoid an Argentinian flag sign with a lens under pressure. She had done everything right. Then, about 90 degrees into creating her capsulorhexis, the patient coughed, and the capsule ran into a “beautiful Argentinian flag sign.” It was a different teaching case now.
Care to avoid the Argentinian flag sign begins preoperatively. Dr. Braga-Mele said the obvious cases to be careful with include white cataract in a younger patient, traumatic cataract that has turned white, cases with bulging of the anterior lens capsule, cases showing a pupillary block-like syndrome, or cases with phacolysis syndrome.
Jeewan Singh Titiyal, MD, said more subtle signs can be viewed at the slit lamp, too.
“The presence of a shallow anterior chamber, increased convexity of the anterior lens capsule, and intralenticular fluid clefts in the anterior lens cortex are indicative of raised intralenticular pressure on slit lamp biomicroscopy. In addition, fellow eye evaluation, especially if phakic, can provide useful clues regarding the anterior chamber depth and anterior capsule convexity,” Dr. Titiyal said.
Different etiologies might cause some white cataracts to have more pressure than others. Preoperative exam and anterior segment OCT or intraoperative OCT can help differentiate, Dr. Titiyal said.
“We use intraoperative OCT to classify white cataract into four variants based on the morphological features and identify intumescent white cataracts with raised intralenticular pressure (ILP).1 Type I cataract are characterized by regular lamellar cortical fibers with no fluid or clefts on iOCT; type II have hydrated swollen cortical fibers with multiple intralenticular clefts; type III have homogenous ground glass regions indicative of cortical liquefaction interspersed with intralenticular clefts; and type IV have extensive liquefaction of the anterior lens cortex,” Dr. Titiyal said.
The classic Argentinian flag sign is associated with type II white cataract, Dr. Titiyal said, requiring “urgent decompression of the intralenticular pressure to prevent capsulorhexis extension.”
Regardless of the etiology, Dr. Braga-Mele said she treats all white cataracts as if they’re under pressure. She always uses trypan blue to stain the capsule and relies heavily on a dispersive viscoelastic. Dr. Braga-Mele uses a 27-gauge needle on a 1-cc syringe that is half filled with balanced salt solution to decompress the lens through a small opening in the anterior capsule; a fluid-to-fluid interface is easier to pull back on than fluid to air interface, she said. She then fills the chamber tightly with the dispersive viscoelastic, and as she’s piercing the anterior capsule, she’s pulling back the plunger to remove any fluff or pressurized cortex.
To preclude this step, Dr. Braga-Mele emphasized giving “verbal anesthesia” when you puncture the anterior capsule and begin your capsulorhexis.
“You want to ask the patient at that point to not cough, don’t talk, don’t move, because if they cause an increase of intra-abdominal pressure, that’s a higher risk for an Argentinian flag sign, no matter how well you’re doing in the anterior segment,” she said.
Dr. Braga-Mele said she starts small with her capsulorhexis. If she completes it, she’ll go around again to make it bigger.
Abhay Vasavada, MD, also uses an unbent 27-gauge needle through a 1-mm incision to puncture the capsule, sucking out the fluid with some balanced salt solution.
“This is unlike the normal anterior capsulorhexis where we make a puncture with a bent cystotome and do a tangential movement to make the slit,” he said, noting that if you were to do this, it would lead to peripheral extension.
Dr. Vasavada said he’ll use microincision forceps to hold a portion of the slit, pushing it further with the forceps to create a large opening with rounded ends that won’t extend. From here, he enlarges the capsulorhexis. He also stains the anterior capsule with trypan blue in all white cataracts.
In some cases, Dr. Braga-Mele said it’s safer to employ an automated capsulorhexis device, such as the femtosecond laser or Zepto (Centricity Vision, formerly Mynosys). Stain with trypan blue, pulling the capsulotomy toward the center, being wary of tags. Dr. Titiyal said he prefers to use the femtosecond laser in all white cataract cases that don’t otherwise have a contraindication (poor pupil dilation, for example).
“Femtosecond laser helps in the creation of a single-step, circular, adequately sized capsulotomy and eliminates the difficulty associated with capsulorhexis in white cataracts. We have observed an abrupt release of white milky fluid during femtosecond laser delivery to be the most important factor affecting the creation of a free-floating capsulotomy,” he said.
Dr. Titiyal also emphasized the importance of staining the capsule to identify residual adhesions of the capsulotomy.
“We could create continuous capsulotomies in 94.1% of cases with fluid and 100% of cases with no fluid with our technique of femtosecond laser-assisted cataract surgery despite the high incidence of micro-adhesions in our study,” he said.2
Dr. Vasavada said he likes using the femtosecond laser, especially for intumescent cataracts. If he thinks it’s necessary from a clinical standpoint, he’ll pay for it on behalf of patients who can’t otherwise afford it.
In manual cases, Dr. Titiyal uses anterior segment or intraoperative OCT to characterize the morphological features of the white cataract and guide his capsulorhexis. He’ll fill the AC with cohesive OVD before starting the capsulorhexis and use a dispersive over the cohesive.
“The cohesive OVD facilitates easy manipulation of the anterior capsular flap and the dispersive OVD tamponades the flap and does not allow the cohesive OVD to escape,” he said.
Dr. Titiyal added that he doesn’t aspirate fluid in all white cataracts, preferring controlled aspiration of subcapsular fluid after initial small capsulorhexis in cases of white cataract with raised ILP/liquefied cortex.
If an Argentinian flag sign does occur,
Dr. Titiyal immediately injects a dispersive OVD over the capsular flap via a paracentesis to tamponade and prevent further extension.
“A gentle bimanual irrigation/aspiration of anterior lens cortex is required to decompress the intumescent cortex. Subsequently, the capsulorhexis may be completed using a microforceps,” he explained.
Dr. Braga-Mele emphasized the importance of maintaining positive pressure in the eye if the capsulorhexis running occurs.
“Your second instrument could be your viscoelastic in your non-dominant hand to keep refilling and maintaining the anterior chamber effectively,” she said.
In an Argentinian flag sign case, Dr. Vasavada said if you see the limbs of the tear floating, there is likely no vitreous. If the sides of the tear are not moving, Dr. Vasavada said vitreous could be sitting on them. In either case, the capsule should be stained to assess the extent of the tear. Triamcinolone can be used to identify vitreous. If there’s no vitreous, Dr. Vasavada said the trick is a slow-motion technique, with a low bottle height and low aspiration flow rate.
“The key is to produce multiple small fragments. If you try to bring a big fragment out, that could further extend and stretch the tear,” he said.
If there is vitreous, Dr. Vasavada recommended a pars plana vitrectomy to prevent extension of the tear and minimize vitreoretinal traction.
In terms of a lens choice, Dr. Braga-Mele said in the aforementioned case, she was able to implant a lens in the capsular bag because the posterior capsule remained intact. If the posterior capsule wasn’t intact, she said you’d want to put a three-piece lens in the sulcus with the haptics 90 degrees away from the Argentinian flag sign to ensure zonular stability. Gluing or sewing the lens might be required if the bag is gone, or if the patient is 85 years or older, you could consider an anterior chamber IOL.
As a final pearl, Dr. Braga-Mele said if the case is a short eye with a white cataract, you could consider acetazolamide preoperatively to decrease IOP from the start.

About the doctors

Rosa Braga-Mele, MD
Professor of ophthalmology
University of Toronto
Toronto, Canada

Jeewan Singh Titiyal, MD
Professor and head
Cornea, Cataract & Refractive Surgery Services
RP Centre for Ophthalmic Sciences
All India Institute of
Medical Sciences
New Delhi, India

Abhay Vasavada, MD
Iladevi Cataract & IOL
Research Centre
Raghudeep Eye Hospital
Ahmedabad, India

References

1. Titiyal JS, et al. Elucidating intraoperative dynamics and safety in posterior polar cataract with iOCT guided phacoemulsification. J Cataract Refract Surg. 2020. Online ahead of print.
2. Titiyal JS, et al. Comparative evaluation of femtosecond laser-assisted cataract surgery and conventional phacoemulsification in white cataract. Clin Ophthalmol. 2016;10:1357–1364.

Relevant disclosures

Braga-Mele
: None
Titiyal: None
Vasavada: Alcon

Contact

Braga-Mele: rbragamele@rogers.com
Titiyal: titiyal@gmail.com
Vasavada: icirc@abhayvasavada.com

Under pressure: Avoiding the Argentinian flag sign Under pressure: Avoiding the Argentinian flag sign
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