Excimer laser trabeculotomy vs 180° selective laser trabeculoplasty in primary open-angle glaucoma. A 2-year randomized, controlled trial

Abstract

To compare the effectiveness and safety of excimer laser trabeculotomy (ELT) ab interno vs selective laser trabeculoplasty (SLT) over 24 months of follow-up in patients with primary open-angle glaucoma (POAG) refractory to medical therapy. This prospective, randomized study included 30 consecutive eyes assigned randomly to either ELT or SLT group. ELT was carried out using a XeCl Excimer Laser with an emission wavelength of 308 nm. Eight spots were equally distributed at a distance of 500 microm from one another over the anterior trabeculum. The SLT patients were treated with a frequency-doubled q-switched neodymium:yytrium-aluminum-garnet laser (wavelength 532 nm). Approximately 50 adjacent, but not overlapping, laser spots were distributed over 180 degrees of the trabecular meshwork, using an energy level ranging from 0.7 to 1.0 mJ per pulse. The main outcome measure was intraocular pressure (IOP) lowering after ELT and SLT. Success was defined as >or=20% reduction in IOP without further glaucoma intervention. At 24 months, complete success rates were 53.3% for the ELT group and 40% for the SLT group (P=0.35, Fisher's exact test); qualified success rates were 33.3% for the ELT and 26.6% for the SLT group (P=0.5, Fisher's exact test).Mean IOP decreased from 25.0+/-1.9 to 17.6+/-2.2 mmHg (-29.6%; P<0.0001) in the ELT group and from 23.9+/-0.9 to 19.1+/-1.8 mmHg (-21%; P<0.0001) in the SLT group. Both ELT and SLT proved to be effective techniques in the treatment of POAG refractory to medical therapy.