Adie Syndrome (Tonic Pupil)

Adie syndrome, also known as tonic pupil, is a neurological disorder that causes you to have one large pupil and no deep tendon reflexes (muscle stretch reflexes).

The pupil is the dark center of your eye. If you have Adie syndrome, one eye’s pupil is larger than the other. The pupil naturally becomes smaller with brighter light and larger in dim light or darkness. In Adie’s pupil, there’s an abnormal response to light where the pupil doesn’t constrict as much as it would normally.

This syndrome most often affects the Achilles tendon, located on the back of your calf, connecting your ankle to your heel. When you gently tap on this tendon, a reflex movement should occur, but no reflex happens with Adie syndrome.

While this condition affects your eyes and reflexes, it isn’t disabling or life-threatening. Treatment options are available if symptoms are bothersome.

You may hear your healthcare provider refer to Adie syndrome by another name, like:

• Adie’s pupil
• Adie’s pupil syndrome
• Adie’s tonic pupil
• Holmes-Adie syndrome
• Tonic pupil of Adie

Adie syndrome affects an estimated 2 people out of every 1,000 around the world.

Adie syndrome signs and symptoms

The two main signs of Adie syndrome are:

• A larger-than-expected pupil that slowly gets smaller in bright light (tonic pupil)
• Slow to no deep tendon reflexes (muscle stretch reflex)

You may notice these signs on one side of your body only, but they may affect both sides.

Symptoms of Adie syndrome that affect your eyes may include:

• Blurred vision
• Light glares
• Light sensitivity

Less common symptoms of Adie syndrome could include:

• Headaches
• Facial pain
• Lack of knee-jerk reflex
• Excessive sweating

Adie syndrome causes

Researchers don’t know exactly what causes Adie syndrome. But studies suggest that damage to the following areas may lead to symptoms:

• Ciliary ganglion: This is a group of nerve cells in your eye socket, behind your eye. It supplies nerves to the muscles that regulate your pupil’s response to light. The ciliary ganglion also manages your eye lens muscles. The lens changes shape so you can focus on objects.
• Dorsal root ganglion: This is a group of nerve cells located outside of your spinal cord near your spinal column. It sends sensory information from your peripheral nervous system (like your muscles) through to your spinal cord.

Damage to these areas may happen after the following:

• Autoimmune conditions (amyloidosis, Guillain-Barre syndrome, lupus, polyarteritis nodosa, sarcoidosis or Sjogren syndrome)
• Infections (COVID-19, HIV, HPV, Lyme disease, syphilis or varicella)
• Ischemia or conditions that affect blood flow and oxygen (giant cell arteritis and vasospasm)
• Trauma
• Systemic autonomic and peripheral neuropathies (Ross syndrome, Harlequin syndrome)
• Tumors

In addition, researchers found a few cases of Adie syndrome after orbital (eye) surgery.

Risk factors

An Adie syndrome diagnosis usually happens between ages 25 tand 45. The average age of diagnosis is 32. It usually affects females more than males. The condition rarely runs in biological families and most often happens sporadically (randomly).

How is Adie syndrome diagnosed?

A healthcare provider and an ophthalmologist (eye care specialist) will diagnose Adie syndrome. They’ll learn more about your symptoms and medical history during a physical exam. Your provider will test your reflexes by tapping on your tendons (areas where your bone and muscles meet), like below your knee or above your heel. They’ll watch for movement after tapping gently.

Your ophthalmologist will examine your eyes. They’ll perform an eye exam and use a slit lamp to examine your eyes more closely. Your provider may give you eye drops (pilocarpine) to see how your pupil reacts. Pilocarpine causes your pupil to constrict (shrink). It’s also common for your provider to shine a bright light over your eye to see how your pupil reacts to light.

How is Adie syndrome treated?

If an underlying infection or condition caused Adie syndrome symptoms, a healthcare provider will offer treatment specific to your situation. This varies from person to person.

Your provider may suggest the following treatment options:

• Prescription glasses for blurred vision
• Sunglasses for light sensitivity
• Pilocarpine eye drops to improve glare

Most commonly, no treatment is needed at all, especially if you don’t have symptoms that affect your vision or health.

When should I see a healthcare provider?

Let a healthcare provider or an eye care specialist know if you notice changes to your vision, like blurry vision or light sensitivity. You should also mention if you notice changes to the size of your pupil when you look at it every day in the mirror. Your providers will offer an exam to check your overall health.

What is the prognosis for Adie syndrome?

Adie syndrome isn’t a life-threatening condition, and it doesn’t lead to disability. The condition may affect your vision in a way that requires you to wear prescription lenses when you read. You may feel more comfortable wearing sunglasses when you go outdoors to prevent discomfort from light sensitivity, but this is different for each person.

While less common, if symptoms of Adie syndrome start on one side of your body, they may spread to the other side over time. For example, if one eye has a tonic pupil, your other pupil may develop it down the road. But this isn’t a guarantee. You may develop angle-closure glaucoma with this condition.

If you lose function of your deep tendon reflexes, it’s usually permanent, and those reflexes won’t return.

What is Ross syndrome?

Ross syndrome is a type of Adie syndrome where you have symptoms of Adie syndrome (tonic pupil and no deep tendon reflexes) with excessive sweating. Treatment options are available to manage this additional symptom.