Selective laser trabeculoplasty: A promising treatment for open angle glaucoma

Selective laser trabeculoplasty (SLT) is a therapeutic modality that utilizesNeodymium: Yttrium aluminium garnet (Nd:YAG) laser to increase outflow facility inthe trabecular meshwork(TM). It selectively targets pigmented cells in the trabecularmeshwork causing little if any damage to trabecular cells. It presumably increasesoutflow facility by altering the composition of the extracellular matrix of the TM.SLT efficacy, safety, and repeatability have been extensively studied. SLT is equallyeffective to Argon Laser Trabeculoplasty (ALT) achieving on average a 20% reductionon intraocular pressure (IOP) despite causing significantly less histologic damage to TM.However, similarly to ALT SLT loses effectiveness over time and is occasionallyaccompanied by IOP spikes immediately after the procedure.SLT is effective irrespective of the amount of TM pigmentation and is particularlyeffective in secondary open angle glaucomas including pseudoexfoliation and pigmentaryglaucoma. The only variable predictive of SLT success is IOP before the procedure.The major theoretical advantage of SLT over ALT is its potential for virtuallylimitless repeatability. However this advantage remains largely theoretical as there arefew studies proving the efficacy of such repeatability.SLT is promising as single therapeutic intervention in third world countries becauseof the low rate of complications, the ease of application and the potential for repeattherapy. Although economic modeling has been used to advocate for widespread use inmanaged care environments, the economic advantages from a public health perspective inthis setting are questionable.