**Core Concept**
Argon laser trabeculoplasty (ALT) is a minimally invasive surgical procedure used in the treatment of glaucoma, specifically to reduce intraocular pressure (IOP) by enhancing the outflow of aqueous humor. It involves the application of argon laser energy to the trabecular meshwork, a spongy tissue located at the base of the iris.

**Why the Correct Answer is Right**
The mechanism of ALT involves the creation of small holes in the trabecular meshwork, allowing for increased outflow of aqueous humor and subsequent reduction in IOP. This is achieved through the selective coagulation of the pigmented epithelium of the trabecular meshwork, which leads to the formation of new pathways for aqueous humor drainage. The argon laser's wavelength (488-514 nm) is selectively absorbed by the pigment, causing localized thermal damage and promoting the outflow of aqueous humor.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because ALT is not used in the treatment of cataracts.
* **Option B:** This option is incorrect because ALT is not a form of incisional surgery, unlike trabeculectomy.
* **Option C:** This option is incorrect because ALT is not used to treat angle closure glaucoma, although it may be used in conjunction with other treatments for this condition.

**Clinical Pearl / High-Yield Fact**
ALT is often used as an adjunctive treatment for glaucoma, particularly in cases where medical therapy has failed to control IOP. It is essential to note that ALT is not a substitute for medical therapy, and patients should continue to receive anti-glaucoma medications after undergoing ALT.

**Correct Answer: B. Trabeculoplasty is used to treat open angle glaucoma.**