May 2020

IN FOCUS

Revolution in Glaucoma Medications
What constitutes maximum medical therapy for glaucoma?


by Vanessa Caceres Contributing Writer

“I think that glaucoma physicians have started to focus on quality of life for our patients, not
necessarily that we didn’t before but new advances in medications and surgery have allowed us more flexibility.”
—Linda Huang, MD





A patient regularly uses multiple glaucoma medications in the left eye (pictured top), which exhibits significantly more redness than the right eye, in which no medications are used (pictured bottom).
Source: Reay Brown, MD

In the quest to lower IOP in glaucoma patients, a glaucoma specialist could conceivably prescribe one medication, then another, and perhaps even more. But is this the most effective way to control IOP?
That’s part of the balancing act with maximum medical therapy.
Often called maximum tolerated medical therapy, the goal is to maximize the IOP-lowering benefits, make sure patients will actually use the medications prescribed, and reduce side effects.
“Often patients are not able to tolerate maximum therapy and are on a curated list of medications to balance effectiveness and side effect profile,” said Linda Huang, MD.
The medications that ophthalmologists use include both topical and oral glaucoma medications. The latter include acetazolamide or methazolamide, but adverse effects on the kidneys or liver may limit their use, said Swarup Swaminathan, MD.
One big component of maximum tolerated therapy is how effective additional medications can be, and that’s where “eye drop math” occurs. “If the clinician expects a 30% reduction in IOP from one medication, and a 20% IOP reduction from another medication when used independently, the concurrent use of both will not reduce IOP by 50% but by slightly less,” Dr. Swaminathan said. “Each additional medication provides reduced gains, so to speak.”
This is why many ophthalmologists give careful thought to the real benefit of adding additional medications to the treatment mix. In fact, when Reay Brown, MD, sees a glaucoma patient for a check-up and the IOP is elevated, he won’t add a new medication. He said the rise in IOP is often a normal fluctuation and a new medication wouldn’t necessarily be helpful. “When you see the patient back, most of the time, the pressure will be significantly lower because of the reversion to the mean,” he said. Holding off on a new prescription initially often avoids trapping patients into chronic use of another medication, he explained.
“The definition of maximum tolerated medical therapy is the same as it was before, but we didn’t have as many options before,” Dr. Brown said. “A patient can be on four or five medications, and although the medications aren’t additive, they do add up in terms of side effects. At some point, we may discontinue a medication, and it’s amazing to me how often the pressure is lower after we stop the medication,” he said.
Dr. Brown thinks two drops is the real limit for effective, adherent treatment. “Any more than that, we’re kidding ourselves that the patients are taking it and that the medications are actually effective,” he said.

The evolution of maximum tolerated medical therapy

Maximum tolerated medical therapy has evolved over the decades, thanks to a greater array of treatment choices.
“I think that glaucoma physicians have started to focus on quality of life for our patients, not necessarily that we didn’t before but new advances in medications and surgery have allowed us more flexibility,” Dr. Huang said. “Maximum therapy now encompasses medical, laser, and surgical approaches.”
There are more options now to reduce medication burden or medication side effects, including preservative-free medications, new drops with daily dosing, new combination drops, and laser therapy, Dr. Huang said.
Newer approaches to treatment such as intracameral sustained delivery of medications and sustained-release drug delivery systems may reduce the need for topical administration, Dr. Swaminathan said. “All of these advances have improved the armamentarium of glaucoma specialists in providing options to patients prior to surgery,” he said.
Of course, more surgical options are available as well.

Using laser and MIGS alternatives

The pendulum seems to have swung in favor of laser and surgical treatments in modern glaucoma treatment, Dr. Brown said. For instance, laser trabeculoplasty is now more popular and is as safe and as good as adding a medication. However, one barrier that he has seen is patient acceptance.
“Somehow we’ve created a feeling among patients that laser use is a very dramatic treatment, and they have the sense that it indicates that their glaucoma is very bad,” Dr. Brown said. For this reason, glaucoma specialists and their staff should spend some chair time to properly explain what laser treatment can offer and how it is a positive alternative to more medications, he advised. The acceptance of laser use over medications needs to permeate among ophthalmologists and staff for patients to accept that message, Dr. Brown added.
Surgical interventions that fall under the category of traditional conjunctival glaucoma surgery (such as trabeculectomy and aqueous shunt implantation) are also available. However, Dr. Swaminathan prefers to consider MIGS options such as viscocanalostomy or goniotomy in patients who have controlled IOP but have significant adverse effects with medications or younger patients who would prefer to avoid conjunctival surgery. Schlemm’s canal stenting procedures can be considered during concurrent cataract surgery, he added.
“Newer MIGS procedures can also lower pressures and decrease medications but with less risks than traditional glaucoma procedures,” Dr. Huang said. “Given the improved safety profile, MIGS procedures can be offered sooner along the treatment algorithm.”
This is something that Dr. Brown has seen as well, especially for patients whose burden of medical therapy is too great financially or in terms of adherence.
The use of MIGS in cataract surgery patients is another exciting possibility, Dr. Brown said. “The opportunity in patients who’ve had cataract surgery is the biggest untapped opportunity without the burden of medical therapy,” he said.

At a glance

• Maximum medical therapy is better defined as maximum tolerated medical therapy.
• The actual number of medications a glaucoma patient can use depends on efficacy, side effects, and patient adherence.
• Maximum medical therapy has evolved due to the wider array of options available now, from different drop forms to laser and surgical treatments.
• Laser treatments are often effective in lieu of medications but require good patient education. MIGS options are also popular.

About the doctors

Reay Brown, MD
Atlanta Ophthalmology Associates
Atlanta, Georgia

Linda Huang, MD
Glaucoma Institute of
Northern New Jersey
Rochelle Park, New Jersey

Swarup Swaminathan, MD
Assistant professor of
clinical ophthalmology
Bascom Palmer Eye Institute
Miami, Florida

Relevant disclosures

Brown
: Glaukos, Sight Sciences
Huang: Glaukos, Sight Sciences
Swaminathan: None

Contact

Brown: reaymary@comcast.net
Huang: lindayhuangmd@gmail.com
Swaminathan: sswaminathan@med.miami.edu

What constitutes maximum medical therapy for glaucoma? What constitutes maximum medical therapy for glaucoma?
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