Adie

Adie, in medical terminology, most often refers to Adie’s pupil, also known as a tonic pupil. It is a neurologic condition affecting the iris that was described by the British physician William John Adie in the early 20th century. The hallmark is a dilated pupil that responds poorly or slowly to bright light but may constrict more readily during accommodation, a phenomenon known as light-near dissociation. The affected pupil is usually larger than the other, and photophobia or blurred near vision can accompany the condition. It commonly begins in one eye but can involve both eyes over time.

The underlying cause is thought to be damage or dysfunction of the postganglionic parasympathetic fibers to the iris, typically at the ciliary ganglion. In many cases the cause remains idiopathic, but Adie’s pupil can be part of a broader autonomic neuropathy. When Adie’s pupil occurs together with diminished or absent deep tendon reflexes, the condition is referred to as Holmes–Adie syndrome.

Diagnosis is suggested by anisocoria that is more pronounced in dim light, slowed or absent pupillary light reflex, and preserved accommodation. Slit-lamp examination may reveal iris sphincter abnormalities or sectoral iris atrophy. A dilute pilocarpine test can confirm denervation hypersensitivity, as the affected pupil constricts with low concentrations of pilocarpine, unlike a normal pupil. It is important to differentiate Adie’s pupil from third-nerve palsy or pharmacologic dilation.

Treatment is generally supportive, as there is no cure. Corrective lenses for near and distance vision help, and low-dose pilocarpine eye drops may be used to improve pupil constriction and symptoms. The prognosis is usually good, with stable symptoms, though reflex abnormalities in Holmes–Adie syndrome may persist. The term Adie’s pupil is eponymous, named for William John Adie.