EyeWorld Asia-Pacific September 2012 Issue

43 September 2012 EWAP GLAUCOMA 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 indicator they will respond well to SLT, said Robert J. Noecker, MD, in private practice, Ophthalmic Consultants of Connecticut, Fairfield, Conn., USA. Because patients with PEX “have a lot of fluctuations and variability in their pressures,” SLT can effectively help to flatten that pressure curve out and then reduce the amount of fluctuations experienced daily, said Brian A. Francis, MD, associate professor of ophthalmology, Doheny Eye Center, Los Angeles, Calif., USA. 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, MD, professor of ophthalmology, Bascom Palmer Eye Institute, Miami, Fla., USA. Conversely, an upside seems to be the procedure’s repeatability, although there are only a few reports on that aspect, Dr. Gedde said. But since there can be a “quite profound pressure response” from this subgroup, “it’s worth a try in most patients,” Dr. Francis said. In fact, “the only special consideration 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, MD, Wills Eye Institute, Philadelphia, Pa., USA. 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 disease 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 impression 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 controversial), but I treat PEX the same as other types of open-angle glaucoma before and after SLT,” he said. Using selective laser trabeculoplasty in pseudoexfoliation glaucoma: Pros and cons by Michelle Dalton EyeWorld Contributing Editor Where to fit it in When to initiate SLT in the PEX patient 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 treatment algorithm to see if it might work; Dr. Gedde mostly uses SLT to supplement tolerated medical therapy; 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. 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 continued on page 44 Views from Asia-Pacific Ivan GOLDBERG, AM MB,BS(Syd), FRANZCO, FRACS Clinical Associate Professor and Head of Glaucoma Unit University of Sydney and Sydney Eye Hospital c/o Eye Associates, Floor 4, 187 Macquarie Street, Sydney, NSW 2000 Australia Tel. no. +61-2-92311833 Fax no. +61-9-92323086 eyegoldberg@gmail.com B oth the high chance of effective intraocular pressure (IOP) reduction and the low risk of an adverse reaction make selective laser trabeculoplasty (SLT) an attractive management strategy in open-angle glaucoma secondary to pseudo-exfoliation (PXF). The technique of administration is important to minimize post-SLT inflammation and/or IOP spike: confluent application of laser energy without overlapping or leaving gaps in trabecular meshwork (TM) treatments, treating no more than 180 degrees of TM at a time and only the second 180 degrees if the IOP response after 4-5 weeks is less than desired, varying the laser application power so as to produce fine champagne bubbles (no more and no less) with each treatment and pre-treating with an alpha-2 agonist and perhaps with weak pilocarpine. We avoid steroid and even nonsteroid anti-inflammatory therapy before or after the treatment. Laser power may be as low as 0.4 mJ with heavily pigmented TM and routinely varies between one part of the TM and another. Because our results have been positive, we now offer SLT as an option to patients at every stage in their management process: initial treatment instead of drops, as an add-on to partly effective drop therapy where the IOP is not yet at target levels, as a substitute for medications with side effects or where instillation is a challenge for the patient or his/her family or carer. It is offered almost universally before incisional surgery is considered. If effective for a patient, SLT has the advantage of eliminating non-adherence and physical barriers to self-instillation as concerns and of side-stepping exposure of ocular tissues to chronic preservatives. If IOP rises after responding initially to the first 180-degree treatment, the second “enhancement” 180-degree SLT is offered routinely. If the entire 360 degrees of TM has been treated with a reasonable response (>20% IOP reduction), maintained for at least 9–12 months, then it is offered again if and when IOP rises. If used thoughtfully and appropriately, SLT can be a helpful management strategy for many patients. Editors’ note: Prof. Goldberg is a consultant for Alcon, Allergan, ForSight Labs (Menlo Park, Calif., USA) and Glaukos, but has no financial interests related to his comments.direct financial interests related to his comments.