Selective laser trabeculoplasty or SLT is an in-office laser procedure that can lower harmful pressure within the eye (intraocular pressure or IOP). If medicated eye drops or oral medications prove ineffective at relieving the eye pressure caused by glaucoma, your doctor may recommend selective laser trabeculoplasty. During the laser procedure, the doctor will direct the laser to the drainage tissues in the eye. The tissue will biologically change as a result and the fluids causing pressure will drain over time.