Purpose: Systemic review to compare selective laser trabeculoplasty (SLT) to other glaucoma treatment options in terms of their intraocular pressure (IOP)-lowering effect.
Methods: Searches of the following databases were performed: PubMed, Cochrane Central Register of Controlled Trials, Ovid, EMBASE, metaRegister of Controlled Trials, and ClinicalTrials.gov. Only randomised controlled trials (RCTs) published in peer-reviewed journals comparing SLT to other glaucoma treatment options were considered. The main outcome measure was the change in IOP from baseline.
Results: An initial search of PubMed identified 23 RCTs with 17 meeting the inclusion criteria. Nine RCTs compared 180° SLT to 180° argon laser trabeculoplasty (ALT) and one trial compared 360° SLT to 360° ALT, all reporting no difference in terms of IOP reduction from baseline. One RCT reported better outcomes with SLT at 1 year but this effect regressed at 2 years. Three trials compared 360° SLT to medical therapy and found no difference between the two treatment options. One trial found greater IOP reduction with latanoprost vs 90° and 180° SLT, and greater IOP reduction with 180° and 360° SLT versus 90° SLT, however no differences were found between 360° SLT versus latanoprost or 360° vs 180° SLT. Two trials compared 180° SLT to 360° SLT finding no difference in IOP reduction. Two trials compared 180° SLT to 90° SLT, one finding no significant difference and one finding greater IOP reduction with 180° SLT over 90° SLT. One trial compared excimer laser trabeculotomy (ELT) to 180° SLT, finding no differences in IOP reduction up to 3 months follow-up but greater IOP reduction with ELT at time intervals between 9 and 24 months. There were no RCTs identified that compared SLT to surgery.
Conclusion: In terms of the IOP lowering effect, there is no difference between SLT and ALT. Three trials indicate no difference between 360° SLT and medical therapy, with one of the trials indicating greater IOP reduction with latanoprost over 90° and 180° SLT. Three trials indicate no difference between 180° SLT and 360° SLT. It is inconclusive whether 90° is less efficacious than 180° SLT. One trial reports greater IOP reduction with ELT over 180° SLT in the long term.