This is a glaucoma laser procedure used to improve the flow of aqueous fluid out of the eye. A laser is applied to the trabecular meshwork, which acts as a filter for the fluid leaving the eye. There are two different types of laser therapy used. ALT is a “hot laser” that creates scar spots in the trabecular meshwork that physically open the meshwork to allow drainage. While effective, ALT can only be done once as the eye can only tolerate so much scaring. SLT is a newer laser technology. It is often described as a “cold laser” because it doesn’t create the same scaring and can be repeated if necessary.