In episcleritis testing, which agent is used to blanch the vessels?

In episcleritis testing, which agent is used to blanch the vessels?

• A. 2.5% Phenylephrine
• B. Tropicamide
• C. Atropine
• D. Cyclopentolate

Answer: (A)

Blanching the superficial episcleral vessels is done with a topical vasoconstrictor. A sympathomimetic like phenylephrine acts on alpha-adrenergic receptors in the ocular vessels, causing rapid constriction of the superficial episcleral veins and arteries. This blanching helps distinguish episcleritis (where vessels blanch) from deeper scleral inflammation in scleritis (where vessels may not blanch as readily). The other drops listed are mydriatics/cycloplegics, which dilate the pupil and paralyze accommodation but do not cause the targeted vascular blanching used for this test. Therefore, the agent used to blanch the vessels is phenylephrine, typically at 2.5%.

Blanching the superficial episcleral vessels is done with a topical vasoconstrictor. A sympathomimetic like phenylephrine acts on alpha-adrenergic receptors in the ocular vessels, causing rapid constriction of the superficial episcleral veins and arteries. This blanching helps distinguish episcleritis (where vessels blanch) from deeper scleral inflammation in scleritis (where vessels may not blanch as readily). The other drops listed are mydriatics/cycloplegics, which dilate the pupil and paralyze accommodation but do not cause the targeted vascular blanching used for this test. Therefore, the agent used to blanch the vessels is phenylephrine, typically at 2.5%.