Which topical medication is contraindicated in patients with Thyroid Eye Disease?

Which topical medication is contraindicated in patients with Thyroid Eye Disease?

• A. Apraclonidine
• B. Timolol
• C. Dorzolamide
• D. Phenylephrine 10%

Answer: (D)

The key idea is that in Thyroid Eye Disease the orbit is already crowded and inflamed, and anything that increases adrenergic stimulation—especially alpha-adrenergic effects that cause pupil dilation—can worsen orbital congestion and risk of optic nerve compression. Phenylephrine 10% is a strong alpha-1 agonist used as a mydriatic; dilation of the pupil in this setting can worsen proptosis and orbital edema, potentially raising intraorbital pressure and compromising optic nerve perfusion. Because of these risks, it is contraindicated in patients with Thyroid Eye Disease. The other options do not produce the same potent alpha-1–mediated dilation or the associated orbital effects, so they are considered safer choices in this context.

The key idea is that in Thyroid Eye Disease the orbit is already crowded and inflamed, and anything that increases adrenergic stimulation—especially alpha-adrenergic effects that cause pupil dilation—can worsen orbital congestion and risk of optic nerve compression. Phenylephrine 10% is a strong alpha-1 agonist used as a mydriatic; dilation of the pupil in this setting can worsen proptosis and orbital edema, potentially raising intraorbital pressure and compromising optic nerve perfusion. Because of these risks, it is contraindicated in patients with Thyroid Eye Disease.

The other options do not produce the same potent alpha-1–mediated dilation or the associated orbital effects, so they are considered safer choices in this context.