Managing the rock hard cataract
Challenging cataract cases
Managing the rock hard cataract
by Faith A. Hayden EyeWorld Staff Writer
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Pearls of wisdom for a successful surgery
Removing a hypermature cataract is not an everyday occurrence at ophthalmology practices in the United States. But these extreme cases do happen with some frequency stateside, particularly in rural areas. Without proper precautions the surgery can head south at an alarming rate, with a sudden jagged strip of white extending end-to-end across the blue-stained capsule. This complication, known as the Argentinian Flag Sign (AFS), is the most common complication for intumescent cataracts and one of the more dangerous. How do you manage a white cataract successfully? Can the Argentinian Flag Sign be avoided altogether? EyeWorld spoke with a number of cataract surgeons who answered those questions and provided surgical pearls to keep fellow physicians out of trouble.
Staining the capsule
Trypan blue overwhelmingly is the staining dye of choice among doctors interviewed, with one physician calling it "a godsend." "We used to have to use things like indocyanine green, which just barely stained the capsule," said Herbert Ingraham, M.D., chairman, ophthalmology department, Geisinger Health System, Danville, Pa. "But even if you do a lousy job staining, with trypan blue you almost always do just fine."
There are two ways to stain the capsule, either under an air bubble or under viscoelastic. Each option has varying appropriateness and degrees of difficulty. For Samuel Masket, M.D., clinical professor of ophthalmology, Jules Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, his staining technique of choice depends on the nature of the case and what viscoelastic he's using. For instance, if he's working with an agent that is strictly cohesive, say Healon GV or Healon5 (sodium hyaluronate, Abbott Medical Optics, Santa Ana, Calif.), he stains under viscoelastic. "However, if it's the dispersive type of visco agent, I prefer to do it under a bubble," Dr. Masket said. "The dispersive agent adheres to the tissue, and if it retains any of the trypan blue, visibility is reduced." Dr. Ingraham also uses the air bubble method, acknowledging that although it provides the deepest stain, the technique may be problematic for surgeons unfamiliar with the process. One trick Dr. Masket suggested to keep the bubble intact is to place a small amount of viscoelastic just inside the incision immediately after making the bubble.
"What this does is act as a sealant," he said. "A tiny patch of visco agent in and at the edge of the incision will tend to prevent air from escaping." If a surgeon isn't comfortable with the air bubble approach, inserting trypan blue over viscoelastic works, too. The stain won't be as deep, but the technique may be easier.
"Put your viscoelastic in, and don't fill it as full as you normally would," Dr. Ingraham said. "Leave the eye a little bit soft, and then put the trypan blue in and just paint it onto the capsule." One pearl Lisa Arbisser, M.D., adjunct clinical associate professor, John A. Moran Eye Center, University of Utah, Salt Lake City, gives trypan users is the dye can be painted on after opening the capsule because it doesn't stain the cortex. "For example, if you're doing a capsulorhexis and it starts to go to the wrong direction, you can paint a little bit of trypan right over that area," she explained. "You'll be able to see it more clearly, and frankly, the fact that it reduces elasticity probably helps in recovering the rhexis."
Preventing and managing the Argentinian Flag Sign
"The Argentinian Flag Sign does not happen easily," said Dr. Arbisser. "It doesn't have to happen to people, and it doesn't happen automatically. It happens because we allow the pressure between the anterior chamber and the posterior chamber to not be stable. We can't always control every environment perfectly every time, but we can come close if we know what we're doing and why." Dr. Arbisser has a number of tips on how to prevent AFS. For example, avoid operating on a traumatic intumescent cataract if there's no risk of phacomorphic glaucoma, leaking, or uveitis. "If you wait a little bit, [the cataract] will organize a little more in most cases and not be so intumescent and risky," she said. If Dr. Arbisser does have to operate on a white cataract, she likes to give a quarter of a gram per kilogram of mannitol (Osmitrol, Baxter Healthcare Corp., Deerfield, Ill.) 15-20 minutes prior to the cut, which helps alleviate posterior and intralenticular pressure.
"You don't want to do it way ahead of time because the patient will have to pee on the table, and you don't want to do it less than 15-20 minutes ahead because it's not effective," she explained. "Mannitol is an osmotic agent, and you have to be a little cautious in the setting of extreme or uncontrolled congestive heart failure or brittle diabetes. But other than that, it's a pretty benign thing to do to someone systematically." In extreme cases, where the lens is so intumescent that it's difficult to pressurize the eye because the chamber has been shallowed by a swollen, almost abscessed lens, Dr. Masket will perform a small posterior vitrectomy. It softens the eye and allows him to deepen the chamber with viscoelastic.
Dr. Ingraham and Abhay Vasavada, M.D., director, Iladevi Cataract & IOL Research Centre, Raghudeep Eye Clinic, Ahmedabad, India, stressed the importance of creating a small capsulorhexis initially. "The larger the rhexis, the greater the chance for the rhexis to extend to the periphery," said Dr. Vasavada. "If you feel you can, do a smaller rhexis than you'd normally do. Then enlarge the rhexis later when you remove the cataract." The doctors also suggest using a more viscous viscoelastic, such as DuoVisc (sodium chondroitin sulfate, sodium hyaluronate, Alcon, Fort Worth, Texas), Healon GV, or Healon5.
"If you don't do these things, and you don't anticipate these things, then [AFS] happens a lot," said Dr. Arbisser. "But if you do these things, it virtually never happens."
Despite best efforts and precautions, AFS can occur in the hands of even the most skilled surgeon. At that point, it's crucial to remember not to panic and calmly prevent the tear from extending around the equator. "While we all like every case to follow our plan, we must accept that the vagaries of human tissue and human skills can allow the atypical to occur," said Dr. Masket. "As long as surgeons have pre-considered the plan they would follow under those given circumstances, they don't have to panic." In an AFS situation, Dr. Masket reminded physicians to take a deep breath and calm down.
"The wonderful thing is one could always remove the instruments from the eye, repressurize the eye with a visco agent, reassess the anatomy, and then make a plan for how to progress," he said. "Fortunately, if you keep your senses, the opportunity exists to regroup your thoughts and go with plan B." Plan B must include finding and securing the ends of the tear and immediately stabilizing the pressure between the anterior and posterior chamber. The eye has to remain static. "You need to add more viscoelastic in a gentle fashion to not overfill or else you're creating pressure that allows the tear to cross the zonules around the equator to the back," said Dr. Arbisser. "Neither can you from now on throughout the case allow the chamber to shallow or it will tear across. So now, for the rest of the case, you must know where the limits of your tear are, keep it covered with visco, and keep your chamber stabilized." When it's time for phaco, Dr. Arbisser favors a vertical chop technique over a divide-and-conquer. "I kind of lollipop the nucleus, divide it into pieces, and suck it up with just enough phaco to be able to assist aspiration," she explained. "I do a vertical chop on that so there's no pushing." Once the nucleus is out, Dr. Arbisser suggested stabilizing the chamber again and taking the time to do a dry cortex removal. "You have to be certain the haptics are where the two totally intact halves of the bag are," she said. "You can't allow it to be in a position where the haptic can pop out of the bag where the tears are and be in the sulcus." This type of complication may slow Dr. Arbisser down to a 45-minute case, which surgeons and staff need to be prepared for. "When I recognize there's an impending complication, I say the word 'timing,'" she said. "Everyone in the room knows we don't prep the person in the next room. We have a tough case bin that we keep extra stuff in. They have that at the ready if I say 'timing.' We're prepared for anything."
Too complicated for phaco
It doesn't happen often, but there can be white cataract cases too complicated for phacoemulsification. Sometimes it's not the cataract itself that's the problem; it's other factors in the eye, such as a compromised cornea and the absence of zonules. In those instances, Dr. Masket will do an intracap or a pars plana vitrectomy. Dr. Ingraham, on the other hand, has on occasion converted the procedure to an extracap or manual small incision surgery because of hypermaturity. He favors the manual small incision over the extracap because he has more control over the eye. Furthermore, manual small incision surgery is the standard during international mission work in a country lacking reliable technology or even power, so it's helpful to keep those skills fresh. "You can phaco anything if you're stubborn enough," said Dr. Ingraham. "I think you challenge the zonules and increase your risk of burning your wound because you're having to put so much power into the eye. It happens much less frequently than it used to because the machines have gotten so much better. "People need to be willing to say, 'I'm getting in over my head,'" he continued. "I think quite often surgeons say, 'This was my plan, and I'm going to stick with that plan come hell or high water.' But as long as we get the cataract out and the patient does well, then [diverting from that] is OK."
Editors' note: Dr. Arbisser has financial interests with Alcon. Drs. Ingraham, Masket, and Vasavada have no financial interests related to their comments.
Contact information
Arbisser: larbisser@eyesurgeonspc.com
Ingraham: hingraham@geisinger.edu
Masket: Ann McLean (assistant to Dr. Masket), avcweb@aol.com
Vasavada: icirc@abhayvasavada.com
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