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34 EW FEATURE February 2011 Pseudoexfoliation July 2012 Using selective laser trabeculoplasty in pseudoexfoliation glaucoma: Pros and cons by Michelle Dalton EyeWorld Contributing Editor AT A GLANCE • SLT can be effective in treating pseudoexfoliation glaucoma • The repeatability of SLT is still debated, but at least 6 months' benefit should be expected before repeating • No consensus exists about when to use SLT in the pseudoexfoliation patient SLT offers several advantages over argon laser, and that may alter when it's used in the treatment algorithm T he prevalence of patients with pseudoexfoliation (PEX) glaucoma varies from about 26 per 100,000 in the U.S. to a high of 23-61% depending on age in Scandinavia. Yet limited published data exists on the efficacy or safety of selective laser trabeculoplasty (SLT) in this group. If patients respond favorably to medications (such as prostaglandins), that's a keen indica- tor they will respond well to SLT, said Robert J. Noecker, M.D., in private practice, Ophthalmic Con- sultants of Connecticut, Fairfield. Because patients with PEX "have a lot of fluctuations and vari- ability in their pressures," SLT can effectively help to flatten that pres- sure curve out and then reduce the amount of fluctuations experienced daily, said Brian A. Francis, M.D., associate professor of ophthalmol- ogy, Doheny Eye Center, Los Ange- les. In these patients, Dr. Francis said the trend "is for lower power, but more spots," with power somewhere around 0.4-0.6 mJ for 140 spots during a 360-degree treatment. A downside to SLT is that it may lose effect over time, said Steven J. Gedde, M.D., professor of ophthal- mology, Bascom Palmer Eye Insti- tute, Miami. Conversely, an upside seems to be the procedure's repeata- bility, although there are only a few reports on that aspect, Dr. Gedde said. But since there can be a "quite profound pressure response" from An example of PEX glaucoma Source: Karl Brasse, M.D., EyeLand Design Network this subgroup, "it's worth a try in most patients," Dr. Francis said. In fact, "the only special consid- eration is that you usually have a fair amount of pigmentation of the angle, so you have to be careful with how much energy you use," said L. Jay Katz, M.D., Wills Eye Institute, Philadelphia. In cases with heavy pigmentation, adjusting the power down or treating 180 degrees at a time rather than 360 might be beneficial, he said. Dr. Francis agreed, adding this group might be more likely to have pressure spikes after laser, and a frank discussion with patients about the potential for more medication to control the spike is warranted. Dr. Noecker said because the dis- ease often presents with asymmetric degrees of damage, SLT may be more effective in one eye than the other. By using SLT in lieu of medication, "the eyes won't look different due to topical therapy—you won't get the hyperemia or eyelash growth on one eye with the other not affected," he said. It is Dr. Gedde's clinical impres- sion that most eyes with PEX behave similarly to primary open-angle glaucoma, so patients should be treated similarly as well. "I'll use an alpha agonist an hour before and immediately after the procedure to minimize the risk of a pressure spike; I tend to use a topical non-steroidal for a few days (although that's con- troversial), but I treat PEX the same as other types of open-angle glau- coma before and after SLT," he said. Where to fit it in When to initiate SLT in the PEX pa- tient is often decided case by case— Dr. Noecker will use it early in a treatment algorithm; Dr. Katz may hold off and use it later to replace medications or earlier in the treat- ment algorithm to see if it might work; Dr. Gedde mostly uses SLT to supplement tolerated medical ther- apy; and Dr. Francis "may offer it as a first line treatment and leave the decision about meds versus laser to the patient." Dr. Gedde finds SLT to be very useful in patients who are poorly tolerant of medical therapy. All four physicians agreed that if patients are beginning to fail one medication and have not had a suf- ficient response to a second or third med, SLT becomes a much more viable option before heading into surgery. "Most people elect to be treated initially with medical therapy, but SLT is a very viable first line treat- ment for open-angle glaucoma," Dr. Gedde said. Another advantage to using SLT? There's 100% compliance, the physicians said. It is effective "in a majority of patients, it's got a very nice safety profile, and the effect is present 24/7 independent of patient adherence. I think it is also a cost-ef- Repeatability? Repeating SLT may be as effective as the initial treatment, some studies have suggested, but everyone noted that when patients do not respond initially, there's really no reason to try a second time. "I need to see at least a 20% pressure reduction that persists for at least a year to consider SLT a viable procedure for repeating," Dr. Gedde said. "Repeat treatment is still very controversial," Dr. Katz said. "It's reasonable to do, but there's a very finite life for the benefit of the laser." He added that the discussion on when (or whether) to use SLT should be part of the informed consent discussion with patients to make them fully aware of all options. Dr. Francis doesn't put a time limit on when he will consider re- peat laser. "I wait until the pressure is climbing back up and there's a loss of effect," he said. "My general rule of thumb is if it only lasted 6 months, I don't think it's practical to continue repeating. I want to see at least a year of response." Dr. Noecker said some of his pa- tients have been treated "at least three times," and "those patients fective treatment long term," Dr. Gedde said, adding the upfront costs of the laser treatment are more than offset by sparing medical therapy.