Adie’s Tonic Pupil
Adie’s tonic pupil refers to a dilated, poorly reactive pupil, presumably from dysfunction of the ciliary ganglion behind the eye. The nerves responsible for pupil constriction connect through the ciliary ganglion. When they are damaged the pupil dilates. Sometimes, over time, the second eye becomes affected. A related condition called Adie’s syndrome occurs when there is loss of deep tendon reflexes as well.
The cause of Adie’s tonic pupil is unknown. There is typically no association with underlying disease of the eye, nerves or brain, with the exception of Adie’s syndrome. In Adie’s syndrome, the deep tendon reflexes may be decreased (the reflexes the doctor tests when banging on your knee with a hammer).
It is important to distinguish an Adie’s tonic pupil from other serious causes of a dilated pupil, such as a brain aneurysm causing a third cranial nerve palsy. In the case of a third cranial nerve palsy, a droopy eyelid and double vision may be present. Dilute Pilocarpine eyedrops can help diagnose Adie’s pupil.
Most people have no symptoms from Adie’s tonic pupil. Sensitivity to bright lights (because the pupil isn’t constricting) is the most common symptom. Vision symptoms are not common but may include glare or diminished ability to focus at near. Over years, the resting pupil size can become smaller and more normal appearing, although a normal response to light doesn’t usually recover.
Treatment is usually not requested. For those with sensitivity to light, sunglasses will help. Occasionally Pilocarpine eye drops, which will constrict the pupil, are prescribed as needed.