Best laser treatment in early stage of primary angle closure glaucoma (PACG) –
💡 Explanation
## **Core Concept**
Primary angle closure glaucoma (PACG) is an ocular emergency characterized by a sudden increase in intraocular pressure (IOP) due to blockage of the drainage angle by the iris. Laser treatments are often used to manage PACG by creating an alternate pathway for aqueous outflow.
## **Why the Correct Answer is Right**
The correct answer, **Yttrium Aluminum Garnet (YAG) laser iridotomy**, is the best initial laser treatment for early-stage PACG. This procedure involves creating a small hole in the iris using a YAG laser, allowing aqueous humor to flow from the posterior chamber to the anterior chamber, thereby bypassing the blocked angle. This helps to decrease IOP and alleviate symptoms.
## **Why Each Wrong Option is Incorrect**
* **Option A:** Argon laser trabeculoplasty (ALT) is primarily used to treat open-angle glaucoma by increasing outflow through the trabecular meshwork. It is not the best choice for PACG.
* **Option B:** Diode laser cyclophotocoagulation is used to reduce aqueous production by ablating the ciliary body and is typically reserved for advanced glaucoma not responsive to other treatments.
* **Option D:** Excimer laser is not commonly used in the treatment of glaucoma; it's more often associated with refractive surgery.
## **Clinical Pearl / High-Yield Fact**
A key point to remember is that YAG laser iridotomy is a prophylactic measure that can be performed on the fellow eye of a patient with unilateral PACG, as the condition can occur bilaterally.