**Question:** Which of the following is/are the side effect/s of using argon laser?

A. Photokeratitis
B. Corneal edema
C. Ocular hypertension
D. Hyphema

**Core Concept:**
Argon laser is a type of laser used in ophthalmology and dermatology for various treatments, such as photocoagulation, phototherapeutic keratectomy, and photodynamic therapy. These procedures involve the application of laser energy to specific tissues, which can lead to localized side effects.

**Why the Correct Answer is Right:**
The correct answer, D (Hyphema), is related to the potential side effects of argon laser usage on blood vessels. Hyphema occurs when laser energy damages blood vessels, causing blood to seep into the anterior chamber of the eye. This can lead to a decrease in visual acuity and increased risk of infection.

**Why Each Wrong Option is Incorrect:**
A (Photokeratitis) and B (Corneal edema) are related to the cornea and ocular surface side effects. Photokeratitis is a burning sensation or pain in the cornea due to laser exposure, while corneal edema occurs when the cornea becomes swollen due to laser-induced damage, impairing vision.

C (Ocular hypertension) is a physiological response to laser treatment, characterized by an increased intraocular pressure. Although ocular hypertension may be a concern after argon laser therapy, it is not a direct side effect of the laser itself but rather a secondary response of the eye to the treatment.

**Clinical Pearls:**
Argon laser therapy has various applications in ophthalmology and dermatology, including treatment of glaucoma, retinal detachment, and skin lesions. While argon laser can be a valuable tool in medicine, it is essential for practitioners to understand the potential side effects and complications to ensure safe and effective treatments for patients.