September 2019

IN FOCUS

Challenging Cataract Cases
Dealing with the unruly iris


by Ellen Stodola EyeWorld Senior Staff Writer/Meetings Editor


Xpand device placed in an IFIS patient with miotic pupil at time of phaco
Source: Blake Williamson, MD

When dealing with the “unruly iris,” surgeons can employ a variety of tools. Cathleen McCabe, MD, Blake Williamson, MD, and Ashvin Agarwal, MD, discussed their preferences in terms of pharmacologic options vs. mechanical iris expansion devices and shared tips for addressing IFIS and iris prolapse.

Pharmacologics vs. mechanical iris expansion devices

Dr. McCabe prefers to use pharmacologic options and almost never uses a mechanical iris expansion device because of the potential damage to the iris. If you can avoid that and keep the pupillary margin without any physical trauma, you end up with a postop pupil that looks untouched and pristine, she said.
Dr. McCabe uses Omidria (phenylephrine and ketorolac, Omeros) and finds it helpful intraoperatively in providing the iris with more tone and sustained dilation. Sometimes even with adequate dilation to begin with, dilation can be lost as surgery progresses, she said.
Dr. McCabe said she sometimes uses compounded phenylephrine. The compounded intracameral injection, which is phenylephrine with lidocaine, helps maintain dilation, she said. She also employs viscoelastics in her cases.
Dr. Williamson said that he tries to use both pharmacologic and mechanical options.
Dr. Williamson uses Shugarcaine on every case, which gives some pharmacologic dilation and stiffens the iris a bit. “I have a low threshold to use an iris expander,” he said. Sometimes the Shugarcaine alone gives cataract access without using an iris expander, but sometimes it doesn’t.
He added that some patients may require mechanical dilation, particularly those on tamsulosin or those who have iris trauma. He said to be mindful of patients with posterior synechiae as well as those with uveitis. Sometimes even narrow angle glaucoma patients can be slow on dilation.
Dr. Agarwal said that while he likes pharmacologic options, they don’t always work for his cases. Pharmacologic options are beneficial, he said, because they are easy to install and don’t destroy the iris structure. There are no manipulation issues that occur with devices.
However, Dr. Agarwal said that in many cases he sees, the patient also has an underlying condition, which means it’s often necessary to use some form of mechanical iris expansion. In these patients, he prefers to use iris hooks.

Omidria, iris stretch, or pupil dilation with a device

Dr. Williamson said he doesn’t personally have experience using Omidria and prefers a device versus using mechanical stretch because you can expand the iris once.
Recently, Dr. Williamson has been using the XpandNT Iris Speculum (Diamatrix). He previously employed the Malyugin ring, but he finds the XpandNT device to be a little more atraumatic with the perfect amount of expansion. The contour fits on the iris and leaves it with a little less trauma, he said.
Dr. McCabe prefers Omidria because there is less likelihood of trauma to the iris, which can result in some postop inflammation, she said.
There are some cases where Omidria may not work, Dr. McCabe added. If you have posterior synechiae where the pupil is bound down to the anterior capsule, it doesn’t matter what pharmacologic agent you use, it’s not going to dilate the pupil, she said.
Once you stretch the pupil, which is Dr. McCabe’s “go-to technique,” it should dilate, and Omidria helps maintain that dilation. In the case of posterior synechiae, you can’t really dilate without stretching the pupil, she said, adding that she uses two Kuglen instruments, usually with dispersive viscoelastic.

IFIS and iris prolapse

When dealing with IFIS, Dr. Agarwal said it’s important not to wait too long to put in an iris hook or Malyugin ring because it can become more flaccid and laxer. “My one tip would be to immediately start using an expansion device,” Dr. Agarwal said. “Once you’ve done that, use high-density cohesive viscoelastic.”
He always has a second instrument in his left hand (with the phaco probe in his right hand) so that it holds in the iris that is coming toward the globe and keeps it at bay and away from the probe. He also stressed the importance of keeping the tool in the center of the pupil to avoid chafing.
Dr. Agarwal offered several other tips on iris prolapse. “Other than prevention, the first rule is never make an incision too posterior,” he said. The minute you make a posterior incision, you will have iris coming because there’s no barrier to the iris structure.
His second tip was to avoid over injecting the anterior chamber with viscoelastic. That will push the iris up and out, making it balloon and be pushed out of the eye through the incision. If this happens, he suggested reducing the pressure inside the eye and taking out as much viscoelastic as possible.
Dr. McCabe said that ideally, she would prefer to have Omidria on every case. There are a significant number of cases where surgeons don’t know preoperatively that they will encounter IFIS intraoperatively. “In those cases, if I have Omidria on board, I know I already have some control over what’s happening with the iris,” she said.
For iris prolapse, when you are aware preop that you have IFIS, Dr. McCabe said making a perfect geometry of the main incision is important. You want a self-sealing incision, you don’t want to make a short incision, and you don’t want one that’s too wide, she said. The incision needs to be properly placed and not too far posterior because this will also facilitate iris egress from the incision.
If you do get iris prolapse, decompress the AC by releasing fluid or viscoelastic from the paracentesis and gently reposit the iris, she said. To do that, she uses a dispersive viscoelastic because, as you reposit the iris, you can use the viscoelastic to create a gentle blockade that pushes the iris posterior to the incision’s inner lip. If the main incision is poorly constructed, it may make sense to create a better incision adjacent to the original incision, Dr. McCabe said.
Small pupils present another challenge. Steps to help facilitate a successful case include good hydration and good lens mobility prior to removing any segments of the nucleus during phaco. Take extra time with hydrodissection to make sure the lens is freely mobile. Dr. McCabe added that with a small pupil, be sure that you have all the cortical pieces and no nuclear fragments are hiding, especially as you’re getting to the completion of I/A and cortex removal.
With the anterior chamber and bag filled with viscoelastic or with the I/A handpiece in the AC, she uses a Kuglen or second instrument through the paracentesis and carefully moves the edge of the pupil and dilates it 360 degrees around by moving the pupil and iris margin peripherally, peeking underneath to make sure there’s no retained cortex or missed nuclear material. She also recommended looking again after placing the IOL.
In cases of IFIS when the iris comes out, Dr. Williamson said he likes to depress from the back of the wound to deflate the AC and lower the pressure. “I find that by letting all the fluid come out of the AC by depressing the posterior lip of the main incision, you can easily deposit the iris back in,” he said. After that, he places a cohesive viscoelastic onto the iris for good spacing between the incision and iris.
Preoperatively, Dr. Williamson said to look for any signs of trauma and synechiae. He also said to be aware if the patient has had laser surgery on the iris and to review any medications that patient is on.
Try to be as atraumatic as possible with iris expander devices in cases of iris prolapse, he warned. Even with moderate manipulation of the iris, you can get iris atrophy.
Dr. Williamson also mentioned IFIS when using the femtosecond laser, adding that he uses the femtosecond laser for about 60–70% of his patients. “I’ve taken great care in these patients to put several dilating drops in after the femtosecond laser is completed,” he said.

At a glance

• Using a pharmacologic option could help avoid trauma to the iris. However, sometimes these options don’t work, at which time you may want to employ a mechanical iris expansion option.
• In cases of IFIS, look for any signs of trauma and any type of synechiae preoperatively.
• When handling iris prolapse, make sure you don’t place your incision too far posterior.

About the doctors

Ashvin Agarwal, MD
Dr. Agarwal’s Eye Hospital
Chennai, India

Cathleen McCabe, MD
The Eye Associates
Bradenton, Florida

Blake Williamson, MD
Williamson Eye Center
Baton Rouge, Louisiana

Relevant financial interests

Agarwal
: None
McCabe: Omeros
Williamson: None

Contact information

Agarwal
: agarwal.ashvin@gmail.com
McCabe: cmccabe13@hotmail.com
Williamson: blakewilliamson@weceye.com

Dealing with the unruly iris Dealing with the unruly iris
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