Eyeworld

EW GLAUCOMA 126 March 2015 by Tony Realini, MD, MPH, EyeWorld Contributing Writer New approach to SLT: Novel technique and application for IOP reduction SLT in action, targeting pigmented trabecular meshwork cells Source: Karl Brasse, MD, EyeLand Design Network S elective laser trabeculoplas- ty (SLT) has been available for more than a dozen years as a means of lower- ing IOP in patients with ocular hypertension and glaucoma. The procedure has been shown Some had SLT retreatment annually regardless of their IOP, and others had SLT repeated only when IOP control began to wane. The investi- gators also included a third group of patients who had undergone a single 360-degree ALT treatment with no repeat, to validate their shift from ALT to SLT. These were patients with IOP in excess of 22 mm Hg with no visual field defects, he said. They were fol- lowed for a minimum of 3 years and as long as 10 years. Only 1 eye per patient was included in the analy- sis. When SLT retreatment failed to reestablish IOP control, or when the one-time ALT wore off, medications were added. The mean IOP throughout follow-up was comparable in all 3 groups, he said, falling from a pretreatment baseline of approxi- mately 25 mm Hg to the 17–18 mm Hg range, he said. "However, the percentage of patients using topical medications at last follow-up was significantly lower (p<0.01) in the annual SLT group (16%) compared to the as-needed SLT (53%) or ALT (62%) groups." The average time from initial treatment to the need for topical medications was also favorable in the annual SLT group (7.4 years) compared to the as-needed SLT (4.8 years) and ALT (3.7 years) groups. Practical applications This study offers intriguing opportu- nities for clinical practice. "Low power SLT, repeated annually, performed better than as-needed SLT retreatment or ALT in reducing the need for medications and the time to medications in newly diagnosed patients with oc- ular hypertension, and can provide IOP control for up to 10 years," Dr. Gandolfi said. This approach takes the guess- work out of trying to determine if SLT has worn off or not, which can be difficult given the variable nature of IOP even in well-controlled pa- tients. EW Editors' note: Dr. Gandolfi has no financial interests related to his comments. Contact information Gandolfi: s.gandolfi@rsadvnet.it Generic glaucoma drugs shown to improve compliance T he first study to examine the impact of a reduction in glaucoma medication copay on patient adherence found that while more than half of glaucoma patients do not take their medications as prescribed, one way to solve this problem may be switching nonad- herent patients to generic drugs, according to the American Academy of Ophthalmology (AAO, San Francisco). Researchers with the University of Michigan Medical School and University of Michigan College of Pharmacy examined claims data from 8,427 glaucoma patients for the 18 months before and after latanoprost became available. All subjects were taking name brand prostaglandin analogues (PGAs) prior to the availability of generic latanoprost, but after the generic drug's introduction, some stayed on the name brand medications while others shifted to the generic drug. The researchers found that while medication adherence improved on average among all patients who were switched to generic latano- prost, those who were on name brand PGAs other than branded lat- anoprost, such as bimatoprost and travoprost, experienced a greater improvement. Among those who had switched from bimatoprost, medication adherence rose, on average, from 47% of the time to 61% of the time. Among those who had switched from travoprost, the average adherence rose from 43% of the time to 54% of the time. EW to lower IOP by approximately as much as a prostaglandin analogue without the need for daily medical adherence or the associated tolera- bility issues. A recent study describes an alternate application for SLT. Annual SLT SLT offers a major advantage over the prior argon laser trabeculoplasty (ALT) platform. "SLT targets pig- mented trabecular meshwork cells without damage to meshwork struc- tures," explained Stefano Gandolfi, MD, University of Parma, Italy. Thus, unlike ALT, when its effect wears off, "SLT can be safely and effectively repeated." Dr. Gandolfi began using SLT as soon as it became available. "For the past 10 years we have given our patients with newly diagnosed ocu- lar hypertension a choice: either the traditional SLT regimen, which is repeated only when its effect wears off, or an annual SLT retreatment to maintain IOP control without wait- ing for it to wear off," he said. For patients who elect to un- dergo repeat SLT only as needed, he uses a standard technique of 70–80 treatment spots distributed over the full 360 degrees of the meshwork, starting with a power of 0.5 mJ and titrating upward until each spot gen- erates tiny champagne bubbles. For those opting for annual retreatment, he uses lower power—0.4 mJ—and places only 40–50 spots throughout the 360 degrees. He and his colleagues recently analyzed the records of 112 sub- jects with ocular hypertension who underwent primary trabeculoplasty.

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