Selective laser trabeculoplasty (SLT) vs other treatment modalities for glaucoma: systematic review

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 degrees SLT to 1801 argon laser trabeculoplasty (ALT) and one trial compared 360 degrees SLT to 360 degrees 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 degrees SLT to medical therapy and found no difference between the two treatment options. One trial found greater IOP reduction with latanoprost vs 90 degrees and 180 degrees SLT, and greater IOP reduction with 180 degrees and 360 degrees SLT versus 90 degrees SLT, however no differences were found between 360 degrees SLT versus latanoprost or 360 degrees vs 180 degrees SLT. Two trials compared 180 degrees SLT to 360 degrees SLT finding no difference in IOP reduction. Two trials compared 180 degrees SLT to 90 degrees SLT, one finding no significant difference and one finding greater IOP reduction with 180 degrees SLT over 90 degrees SLT. One trial compared excimer laser trabeculotomy (ELT) to 180 degrees 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 degrees SLT and medical therapy, with one of the trials indicating greater IOP reduction with latanoprost over 90 degrees and 180 degrees SLT. Three trials indicate no difference between 180 degrees SLT and 360 degrees SLT. It is inconclusive whether 90 degrees is less efficacious than 180 degrees SLT. One trial reports greater IOP reduction with ELT over 180 degrees SLT in the long term.