Eyeworld

EW GLAUCOMA 40 December 2015 by Nathan Radcliffe, MD a very minimal decrease in pressure with an adjunctive agent may not be worth it if there is an increased chance of decreased compliance—es- pecially when that adjunctive agent adds an entirely new category of risk associated with side effects and/or ocular surface intolerability. Lee and colleagues demonstrat- ed that when SLT was added to med- ications, there was further reduction in IOP and medication use without significant decreases in quality of life or worsening of medication tolera- bility. 5 #6: Trouble with compliance Closely related to the previous cat- egory is when there is concern for a patient's compliance with primary therapy. I have developed a zero tolerance policy for patients who miss drops because there are viable alternate options, and SLT tops the list. Studies suggest that about 40% of patients miss an eye drop instil- lation (or use it incorrectly) in the week leading up to appointment. We can help these patients achieve their target pressure with laser. When a patient takes drops, the SLT and drops are equivalent in terms of efficacy, but when the patient does not take drops, there is no question the laser is a better choice. However, SLT is highly successful as a repeat procedure. Patients who re- spond to a first procedure can expect a similar response with a secondary procedure. 2,3 However, the outcome of previ- ous SLT does not necessarily predict if a secondary procedure will work. Khouri and colleagues showed that a repeat SLT procedure will be effec- tive even in patients who did not demonstrate a great response to ini- tial SLT therapy. 4 Therefore, repeat SLT can be offered to both the previ- ous SLT responders and to previous SLT non-responders. Note that this is not typically the case with people who have not previously responded to a given class of medications. #5: Adjunctive therapy as an alternate to more drops Tanna performed a meta-analysis on adjunctive pressure lowering with a variety of glaucoma medications and found that an additional 2 to 3 mm Hg drop in pressure is added with a second drop, almost irrespective of the class of agent used (there is some variance, but overall, there is a very minimal difference). However, whereas adding a second agent will lower pressure, it also has the effect of reducing overall compliance. In many patients, adding a second drop is a zero-sum gain. This is the ideal scenario to try SLT: The potential for paying for and remembering to use topical medications likely outweigh any benefits of pressure-lowering therapy because his overall risk of visual impairment is so low. In this case, shouldn't the treatment be low impact as well? SLT would more like- ly than not successfully replace the pressure lowering of a prostaglandin analog and restore the patient's quality of life. #2: SLT as primary therapy SLT is commonly used as a replace- ment for previous therapy that has failed for reasons of inadequate efficacy or because the patient had a complication. As shown by Waisbourd and Katz, however, SLT is also an excellent option for first- line therapy of glaucoma, offering several advantages including conve- nience, compliance and tolerability, in addition to efficacy that is similar to eye drops. 1 #3 + 4: Previously successful SLT … and previously unsuccessful SLT One of the benefits of SLT is that it is a repeatable procedure. It has largely replaced argon laser trabeculoplas- ty (ALT), which promises roughly equivalent efficacy, but which is ablative to the trabecular meshwork and is therefore not repeatable. Physician explains why the pool of potential patients for SLT may be wider than you think O ver the past year, many of my patients have bene- fited from selective laser trabeculoplasty (SLT). In observing these outcomes, I have come to realize that although SLT is beneficial for a wide range of patients, there are differing reasons why it is a successful strategy. In this article, I will discuss the 10 patient types I think benefit from SLT thera- py. Of note, these are not necessarily presented in rank order, as each patient type will benefit from SLT, albeit for different reasons. #1: SLT as a replacement for drop therapy As I look at successes that I have had with SLT over the past several years, it is clear to me that SLT is more successful the earlier you use it in the treatment paradigm. Indeed, this is true of most therapies. Consider the patient who really needs a trab- eculectomy or a tube shunt to help control his or her pressure, but who is resistant to undergo an invasive incisional glaucoma procedure. These are the kinds of patients who exhibit poor control on four or five topical agents, and nothing seems to work. While I will use SLT in these kinds of patients, I adjust my ex- pectations for outcomes. When the pressure is 40 mm Hg, a 35% pres- sure reduction may not be sufficient, and we are setting ourselves—and the SLT procedure—up for failure if we expect a miracle outcome. This is something I tell surgeons learning the ins-and-outs of SLT: Do not start with the impossible cases; set your- self up for success. Contrast the above scenario to simply using SLT as a replacement for eye drops in patients who are having problems with eye drops but who have controlled intraocular pressures. For example, consider a 75-year-old man who has exam findings that place him somewhere between being a high risk glaucoma suspect and having early primary open-angle glaucoma. Even with minimal symptoms from eye drops, the quality of life downsides of Ten patient types who can benefit from SLT SLT may be beneficial in patients who are having problems with eye drops or who have insurance issues, according to Dr. Radcliffe.

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