EyeWorld Asia-Pacific December 2019 Issue

EWAP DECEMBER 2019 57 GLAUCOMA I n glaucoma surgery, the less invasive, the better. Fortunately, laser and ultrasound technologies employed as primary or adjunctive therapies seem to offer viable, less invasive options. According to Prof. Anastasios G. Konstas, MD, PhD in a presentation at the 23rd European Society of Cataract and Refractive Surgeons Winter Meeting, noninvasive procedures can be reasonably effective in lowering IOP while offering improved safety over more invasive surgeries. “ Today, noninvasive glaucoma procedures (NIGP) do not require eye penetration, differentiating them from MIGS, which requires small incisions and instruments entering the eye,” Prof. Konstas said. “Evidence suggests that the success of laser trabeculoplasty is greater when employed as initial therapy or early in stepwise medical therapy. The pereception of limited success of this treatment in the past was yÕiVi` LÞ Ìi ÕÃi v >ÃiÀ >Ã > ¼>ÃÌ ÀiÃÀÌ LivÀi wÌiÀ} surgery.” Current and emerging NIGP NIGPs include the established argon laser trabeculoplasty (ALT) as well as more recent additions, such as selective laser trabeculoplasty (SLT) and micropulse laser trabeculoplasty (MLT). Some of the newest innovations comprise procedures such as deep wave trabeculoplasty, therapeutic ultrasound, and ultrasonic circular cyclocoagulation. Laser trabeculoplasty (LT) was shown to be successful in lowering IOP for OAG patients. The mechanisms of LT action are not fully understood and evidence is lacking to support the superiority of any particular form of laser. One theory on the mechanism of action of LT says that laser burns induce contracture and stretching of the adjacent tissues, thereby widening the trabecular pores. Another theory proposes a cellular mechanism action, in which LT induces cell division with subsequent renewal of cellularity. A biochemical mechanism of action suggests the renewal of MMPs on the beams and stimulation of macrophages as the means by which LT ultimately reduces IOP. These mechanisms of action are thought to work together and are not mutually exclusive. ALT ALT is the most tried and tested NIGP. It treats the trabecular meshwork aiming Ì i>Vi Ìi ÕÌyÜ v>VÌÞ° IOP reduction with ALT was 24–30% a year after treatment in one investigation, however, all researchers generally have documented a gradual decline ivwV>VÞ ÛiÀ Ìi] >Ã ÜÌ lasers overall. Evidence suggests that primary ALT lowered IOP more than initial therapy with timolol and was at least as effective in «ÀiÃiÀÛ} ÛÃÕ> wi` >` «ÌV disc status over a period of more than 5 years . Other data shows that primary SLT had similar IOP lowering effects as latanoprost over 12 months of follow-up. More recently, SLT employed as sole therapy was shown to be very effective, reducing IOP between 29–39%, with patients achieving and maintaining target IOP after 12 months and demonstrating a success rate of almost 80%. “LT could be a very interesting choice for therapy particularly in patients with exfoliative glaucoma. We know that laser has a better safety «Àwi Ì> i`V> À ÃÕÀ}V> therapy, and it is cost effective. Evidence shows that LT in some elderly patients eliminated any further need of medical therapy. Another study on long-term Noninvasive, laser trabeculoplasty for IOP reduction: Indications are evolving by Stefanie Petrou Binder, MD EyeWorld Contributing Writer Contact information Konstas: konstas@med.auth.gr This article originally appeared in the September 2019 issue of EyeWorld . +V JCU DGGP UNKIJVN[ OQFKƂGF CPF CRRGCTU here with permission from the ASCRS Ophthalmic Services Corp.