Which of the following anti – glaucoma drug can likely cause black pigmentation on conjunctiva
**Core Concept**
The question is testing the side effect profile of anti-glaucoma medications, specifically their potential to cause ocular pigmentation changes. The correct answer is related to a class of medications that can lead to deposition of melanin in the conjunctiva, leading to a characteristic black pigmentation.
**Why the Correct Answer is Right**
Ergot derivatives, such as epinephrine (also known as adrenaline), can cause black pigmentation on the conjunctiva. This is due to the oxidation of epinephrine, which leads to the formation of melanin. The melanin deposits in the conjunctiva, resulting in a characteristic black pigmentation. This is a well-known side effect of topical epinephrine, which is used to reduce intraocular pressure in glaucoma patients.
**Why Each Wrong Option is Incorrect**
* **Option A:** Beta-blockers, such as timolol, can cause a range of side effects, including systemic effects like bradycardia and hypotension, but they are not associated with black pigmentation on the conjunctiva.
* **Option B:** Carbonic anhydrase inhibitors, such as acetazolamide, can cause a range of side effects, including metabolic acidosis and electrolyte imbalances, but they are not associated with black pigmentation on the conjunctiva.
* **Option C:** Prostaglandin analogs, such as latanoprost, can cause a range of side effects, including iris pigmentation and eyelash growth, but they are not associated with black pigmentation on the conjunctiva.
**Clinical Pearl / High-Yield Fact**
Remember that the oxidation of epinephrine can lead to the formation of melanin, which deposits in the conjunctiva, resulting in black pigmentation. This is a characteristic side effect of topical epinephrine, which is used to reduce intraocular pressure in glaucoma patients.
**Correct Answer:** C. Epinephrine