Selective laser trabeculoplasty is a great advance in the surgical treatment of intraocular pressure (IOP) in patients with open-angle glaucoma. It works by using a specific wavelength to irradiate and target only the melanin-containing cells in the trabecular meshwork, without incurring collateral thermal damage to adjacent non-pigmented trabecular meshwork cells and underlying trabecular beams. When treated with SLT, a primarily biologic response is induced in the trabecular meshwork, which involves the release of cytokines that trigger macrophage recruitment and other changes leading to IOP reduction.