Argon Laser Trabeculatomy, Iridotomy (In Eye Blood Pressure)

Argon laser trabeculoplasty (ALT):

In this method defined by Wise and Witter, laser pulses are applied to the pigmented and non-pigmented trabecular mesh border using a spot with a diameter of 50µ. ALT, which is used in open-angle glaucoma cases, causes the opening of trabecular pores and an increase in conventional outflow as a result of scarring caused by thermal energy. In addition, cytokines and macrophage activation resulting from inflammation further increase outflow. Starting at 300mW using a green or blue-green argon laser, the power is increased up to 1000mW until tissue fading occurs. In a single session, the process is performed as 50 shots at 180°. If the desired effect is not achieved, the remaining 180° can be treated in the same way in a second session. Today, it has been replaced by selective laser trabeculoplasty (SLT) due to its side effects such as increased ALT inflammation, increased IOP and peripheral anterior synechia (PAS).

Argon laser peripheral iridoplasty (ALPI)

Argon laser peripheral iridoplasty (ALPI) exerts its effect by mechanically pulling the peripheral iris over the trabecular meshwork, widening the angle. It is performed in the plateau iris, in acute angle-closure glaucoma where laser iridotomy cannot be performed, or in angle-closure glaucoma in which mechanisms other than the pupillary block mechanism that does not improve with laser iridotomy are effective. It is also called “gonioplasty”. It is preferred as primary treatment before LPI in acute attack. Argon or Nd:YAG laser is used, the spot size is 500µm, the effect time is 0.5s, the power is between 200-400mw and it is applied as 20-24 spots at 360º. Thus, burns occur that contract the iris stroma, and the peripheral iris moves away from the angle and the angle is opened.