February 2017

 

CATARACT

 

Cataract editor’s corner of the world

Choosing the right IOL for the advanced glaucoma patient


by Lauren Lipuma EyeWorld Contributing Writer

 
 

Rosa Braga-Mele, MD

 

Performing cataract surgery on the glaucoma patient can at times present a treatment “scotoma” for the cataract surgeon.
Many questions arise such as how extensively to evaluate the patient for the extent of glaucoma—is there any visual field losses or nerve fiber layer damage that could cause issues with vision and contrast sensitivity? Which IOL is the best choice for these patients? And should the cataract surgery be the sole initial procedure, or would it be best to do a combined procedure with either a traditional filter or a MIGS procedure?
In this month’s “Cataract editor’s corner of the world,” we have three glaucoma experts who help us explore the world of cataract and glaucoma and help us better understand and perhaps find answers to the questions posed above.

Rosa Braga-Mele, MD,
MEd, FRCSC,
cataract editor

Experts discuss which lens types and surgical options deliver the best refractive outcomes

Optimizing visual outcomes for glaucoma patients undergoing cataract surgery can be challenging; visual field defects and a loss of contrast sensitivity can limit the IOL options available to the patient. Here, glaucoma experts Lama
Al-Aswad, MD, MPH, associate professor of ophthalmology, Columbia University Medical Center, New York; Constance Okeke, MD, MSCE, Virginia Eye Consultants, Norfolk, Virginia; and Douglas Rhee, MD, professor of ophthalmology, Case Western Reserve University School of Medicine, Cleveland, discuss which types of IOLs they use and which they avoid in patients with advanced glaucoma.

Preoperative evaluation

Determining which type of IOL is best for a glaucoma patient starts with the preop evaluation, according to Dr. Okeke. She first evaluates the severity of the glaucoma, whether the patient wants or needs to reduce the number of medications he or she is taking, and whether the patient has significant ocular surface disease that needs to be addressed.
Next, Dr. Okeke looks at the patient’s visual field to get an idea of what options the patient has in terms of lens choice as well as a sense of what visual outcomes can realistically be achieved through surgery.
“This is something I would typically also show to patients to let them know what level of glaucoma they have and what kind of expectations they can have after the surgery,” she said.
Dr. Okeke then evaluates whether there is a significant risk of a pressure spike that can compromise the fragile optic nerve during surgery. “That can help me decide whether there’s a need for a combined procedure,” she said.
After addressing the glaucoma issues, she turns to addressing the cataract itself—whether it would be a straightforward procedure or a more difficult removal.
“Assessing the kind of cataract will also help me get a better idea of what kind of lens choice I have, based on the type of the cataract,” she said. “These things need to be evaluated and discussed prior to the surgery so there is an understanding of what the limitations are based on the glaucoma and what realistic expectations there are when the cataract is removed.”

Optimal lens choice

All three physicians recommend avoiding multifocal IOLs in advanced glaucoma patients.
“With advanced glaucoma, patients already have a significant loss in contrast sensitivity due to the nature of the disease,” Dr. Okeke said. “This coupled with the loss of contrast sensitivity that comes with a multifocal lens via the dynamics of the ring design does not allow patients to have the best capable vision at any of the three distances that a multifocal can give, and it leaves them at a disadvantage.”
Dr. Rhee also cautions against using multifocal lenses for early or mild glaucoma patients. “Even in early glaucoma patients, I would avoid multifocal lenses because you don’t know with any real certainty whether the patient’s disease is going to progress,” he said.
Dr. Okeke also sees the best visual outcomes when each eye has the same focal point, so she avoids monovision in advanced glaucoma patients.
“[If] one eye sees at distance while the other sees near, there is a risk that the glaucoma can continue to worsen and there’s going to be a strain on that one eye for that particular distance, and they may not be able to see as optimally given their various blind spots,” Dr. Okeke said. “So it’s my opinion that monovision for an advanced glaucoma patient is not going to be the best option.” However, early or moderate glaucoma patients can be good candidates for monovision, she said.
Toric IOLs can be great options for advanced glaucoma patients under the right conditions, according to the physicians.
“With MIGS procedures, I think toric implants are perfectly appropriate,” Dr. Rhee said. “But I would be very cautionary in using them in a combined cataract and filtration surgery, if the intended surgery is either a trabeculectomy or a tube shunt, as both procedures can cause a change in the astigmatism that is measured preoperatively.”
However, if a patient has had a previous trabeculectomy or a tube shunt implanted, toric IOLs are a great option because they can correct any astigmatism induced by the prior procedure, according to Dr. Al-Aswad.
Drs. Al-Aswad and Okeke agreed that extended range of vision lenses, such as the Tecnis Symfony lens (Abbott Medical Optics, Abbott Park, Illinois), could be an option for advanced glaucoma patients. Dr. Okeke used the Symfony lens in early to moderate patients with good outcomes, she said.
“In theory, there’s potential in the future that the expanded focus IOL might be an option, but we need more studies on that in glaucomatous patients because it does not decrease the quality of vision, it doesn’t split the light,” Dr. Al-Aswad said.

Combined surgery

Combined surgery is always an option for advanced glaucoma patients, according to the physicians.
“I have a low threshold for considering a combined procedure with a MIGS. I think that these combined procedures provide a wonderful opportunity to improve the quality of life for glaucoma patients,” Dr. Okeke said. A combined procedure also has the potential to improve the patient’s ocular surface disease, which may play a role in their reduced quality of life and the burden they have relating to drops, she said.
Dr. Al-Aswad tends to perform combined cataract and trab or tube surgery if the cataract is visually significant and the patient’s IOP is uncontrolled, borderline controlled, or controlled but the patient is on maximum medical therapy.
“I tend to do combined procedures because I feel they have quicker visual recovery and, in my hands, very good outcomes,” she said.
She offers MIGS with cataract surgery for any patient with mild to moderate glaucoma on one or more medications.
For advanced glaucoma, she typically does a combined cataract surgery with a trabeculectomy, but may go directly to a tube shunt if the patient has issues with compliance or has difficulty getting to the office. “I usually evaluate patients themselves, their activities, what they like to do, what they want, and what they expect,” she said.

Editors’ note: Dr. Okeke has financial interests with Glaukos (San Clemente, California) and NeoMedix (Tustin, California). Drs. Al-Aswad and Rhee have no financial interests related to their comments.

Contact information

Al-Aswad
: laa2003@cumc.columbia.edu
Okeke: iglaucoma@gmail.com
Rhee: dougrhee@aol.com

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The pros and cons of multifocal and accomodating IOLs by Enette Ngoei EyeWorld Staff Writer

Getting up-close and personal with new accommodative IOLs by Maxine Lipner Senior EyeWorld Contributing Editor

Presbyopia-correcting IOL pearls by Faith A. Hayden EyeWorld Staff Writer

A step-by-step approach to the glued IOL technique by Amar Agarwal, M.S., F.R.C.S., F.R.C.Ophth.

Phakic IOL update: Current technology, new uses, advantages, and drawbacks by Matt Young EyeWorld Contributing Editor

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