Which agent is used with phenylephrine for adult dilation?

Which agent is used with phenylephrine for adult dilation?

• A. Tropicamide 1%
• B. Homatropine 2%
• C. Cyclopentolate 2%
• D. Benoxinate + Fluorescein

Answer: (A)

Phenylephrine dilates the pupil by stimulating the iris dilator muscle (alpha-1 receptors). For adults, it’s typically paired with a short-acting mydriatic that also provides some cycloplegia without lasting effects. Tropicamide 1% fits this role well: it rapidly antimuscarinically dilates the pupil with a quick onset and short duration, making it the preferred partner with phenylephrine for routine adult dilation. The other options either are longer-acting cycloplegics (which delay recovery and increase side effects) or, in the case of benoxinate with fluorescein, are not dilating agents at all but an anesthetic/dye used for other purposes.

Phenylephrine dilates the pupil by stimulating the iris dilator muscle (alpha-1 receptors). For adults, it’s typically paired with a short-acting mydriatic that also provides some cycloplegia without lasting effects. Tropicamide 1% fits this role well: it rapidly antimuscarinically dilates the pupil with a quick onset and short duration, making it the preferred partner with phenylephrine for routine adult dilation.

The other options either are longer-acting cycloplegics (which delay recovery and increase side effects) or, in the case of benoxinate with fluorescein, are not dilating agents at all but an anesthetic/dye used for other purposes.