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I REVOLUTION IN GUCOMA MEDICATIONS N FOCUS 60 | EYEWORLD | MAY 2020 by Vanessa Caceres Contributing Writer 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 medica- tion," 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 pa- tients 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 pa- tients, 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. I n the quest to lower IOP in glaucoma patients, a glaucoma specialist could con- ceivably 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-low- ering 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" oc- curs. "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 of- ten 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, What constitutes maximum medical therapy for glaucoma? At a glance • Maximum medical therapy is better defined as maximum tolerated medical therapy. • The actual number of medica- tions 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 medica- tions but require good patient education. MIGS options are also popular. "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