Adie's pupil is a benign condition caused by damage to the postganglionic parasympathetic innervation of the iris sphincter (ciliary ganglion or short ciliary nerves), resulting in a unilaterally dilated pupil with impaired light reactivity but preserved (tonic) near response. [1-2] It predominantly affects women aged 20–50 and is most often idiopathic (Holmes-Adie syndrome) but can be associated with infectious, autoimmune, or paraneoplastic etiologies. [1-2]
1. History
- Onset: Typically acute or subacute; patient notices one pupil is larger, often discovered incidentally (e.g., looking in a mirror, noticed by others)
- Blurred vision (especially near tasks) and photophobia are the most common complaints [1]
- Ask about recent viral illness (postinfectious etiology, including COVID-19) [3]
- Timing: Constant vs. intermittent; duration of symptoms
- Associated symptoms: Diplopia (suggests CN III palsy instead), headache, ptosis, eye pain
- Important negatives: No ptosis, no extraocular movement limitation, no headache/worst headache of life, no trauma, no topical eye drop or medication exposure (anticholinergics, scopolamine patches)
2. Alarm Features
- Ptosis + ophthalmoplegia + dilated pupil → CN III palsy; must rule out posterior communicating artery aneurysm urgently [2][4]
- Headache (especially thunderclap) with dilated pupil → subarachnoid hemorrhage
- Bilateral mydriasis with altered mental status → consider brainstem pathology, toxicologic emergency
- New-onset diplopia or extraocular movement deficit accompanying the dilated pupil
- Signs of systemic autonomic dysfunction (orthostatic hypotension, anhidrosis) → consider generalized neuropathy, Shy-Drager, pandysautonomia [2]
- Bilateral tonic pupils in the setting of areflexia and ataxia → Miller-Fisher syndrome / Guillain-Barré variant [5-6]
3. Medications
- Relevant contributors to mydriasis (mimics): Topical anticholinergics (atropine, cyclopentolate, tropicamide), scopolamine patches, ipratropium nebulizer mist, sympathomimetics (phenylephrine), jimsonweed exposure [1-2]
- Treatment: Dilute pilocarpine (0.125%) can be used therapeutically for symptomatic blurred vision [1]
- Reading glasses may help with accommodative difficulty
- No systemic medications are routinely indicated for isolated Adie's pupil
4. Diet
- No specific dietary triggers or recommendations
- Not applicable for this condition
5. Review of Systems
- Neurologic: Headache, diplopia, facial weakness, limb weakness/numbness, gait instability, difficulty swallowing
- Autonomic: Orthostatic dizziness, abnormal sweating patterns (segmental anhidrosis → Ross syndrome), urinary retention, constipation
- Infectious: Recent febrile illness, rash, genital ulcers (syphilis), tick exposure (Lyme)
- Rheumatologic: Joint pain, dry eyes/mouth (Sjögren's), malar rash (SLE)
- Constitutional: Weight loss, night sweats (paraneoplastic)
6. Collateral History and Family History
- Confirm no one else noticed ptosis or eye deviation (helps rule out CN III palsy)
- Ask about prior photographs to establish baseline pupil size
- Family history of autonomic neuropathies, hereditary sensory neuropathies, or spinocerebellar ataxias [2]
- Social history: Alcohol use (chronic alcoholism associated with neuropathic tonic pupils), sexual history (syphilis risk) [2]
7. Risk Factors
- Female sex, age 20–50 [1-2]
- Recent viral or respiratory illness (postinfectious mechanism) [3]
- Syphilis (most common infectious association) [1]
- Autoimmune disease: SLE, Sjögren's syndrome [2]
- Diabetes mellitus [2]
- Chronic alcoholism [2]
- Paraneoplastic syndromes [1]
- Orbital trauma or surgery (damage to ciliary ganglion)
8. Differential Diagnosis
- CN III (oculomotor nerve) palsy — the most dangerous mimic; always accompanied by ptosis and/or extraocular movement limitation; pupil-involving CN III palsy requires emergent vascular imaging to rule out posterior communicating artery aneurysm [2][4]
- Pharmacologic mydriasis — topical anticholinergic exposure; pupil will NOT constrict to 1% pilocarpine (unlike Adie's, which will) [1-2]
- Argyll-Robertson pupil — bilateral small irregular pupils with light-near dissociation; associated with neurosyphilis; pupils are miotic, not mydriatic [1]
- Physiologic anisocoria — ≤1 mm difference, both pupils react normally to light; present in ~20% of the population [7]
- Traumatic mydriasis — history of blunt ocular trauma; iris sphincter tears visible on slit lamp
- Congenital mydriasis — lifelong history, often confirmed by old photographs
- Horner syndrome — the smaller pupil is abnormal (miosis + ptosis + anhidrosis); anisocoria worse in dark [2]
9. Past Medical History
- Prior episodes of tonic pupil (may become bilateral over time; ~4% per year)
- History of syphilis, HIV, diabetes, autoimmune disease
- Prior orbital surgery or trauma
- History of autonomic dysfunction
- Guillain-Barré syndrome or Miller-Fisher syndrome [5-6]
10. Physical Exam
- Pupil size and shape: Affected pupil is dilated (mydriatic); may appear irregular due to segmental iris sphincter palsy [2]
- Light reflex: Absent or markedly diminished direct and consensual light reflex on the affected side [1]
- Near response: Tonic constriction to accommodation (light-near dissociation) — the pupil slowly constricts with sustained near effort and then slowly redilates (the "tonic" component) [2]
- Slit lamp: Segmental vermiform (worm-like) movements of the iris sphincter on slit lamp examination — pathognomonic [2][8]
- Extraocular movements: Full — any limitation suggests CN III palsy, not Adie's [2]
- Ptosis: Absent in Adie's; presence suggests CN III palsy
- Deep tendon reflexes: Diminished or absent (Holmes-Adie syndrome) [2]
- Vital signs: Typically normal; check orthostatics if autonomic dysfunction suspected
11. Lab Studies
- Not routinely needed for classic, isolated Holmes-Adie syndrome in a young woman
- If atypical features or concern for secondary cause:
- RPR/VDRL and FTA-ABS (syphilis) [1][4]
- CBC, CMP, ESR, CRP
- HbA1c or fasting glucose (diabetes)
- ANA, anti-SSA/SSB (autoimmune screen)
- Lyme serologies if endemic area
- Anti-ganglioside antibodies (GQ1b, GT1a) if Miller-Fisher or GBS variant suspected [5]
- Paraneoplastic panel if constitutional symptoms present
12. Imaging
- Not required for classic isolated Adie's pupil with no ptosis and full extraocular movements
- Urgent MRA or CTA of the head is indicated if CN III palsy cannot be excluded (ptosis, ophthalmoplegia, or any extraocular movement deficit with a dilated pupil) [2][4]
- MRI brain with contrast if concern for compressive or infiltrative lesion
- Imaging is unnecessary when the clinical picture is classic and the dilute pilocarpine test is confirmatory
13. Special Tests
Dilute pilocarpine test — the confirmatory diagnostic test
- Instill 0.0625% pilocarpine (or 0.125%) in both eyes
- Wait 30–40 minutes
- The Adie's pupil will constrict due to denervation supersensitivity; the normal pupil will not constrict significantly [9-10]
- 0.0625% pilocarpine has superior diagnostic accuracy (AUC 0.954) compared to 0.125% (AUC 0.840); a change in maximal pupil diameter ≥0.5 mm has 100% sensitivity and 82.8% specificity [9]
1% pilocarpine test — used to rule out pharmacologic mydriasis:
- If the pupil does NOT constrict to 1% pilocarpine → pharmacologic blockade (atropine/anticholinergic exposure) [2][11]
- Both Adie's pupil and CN III palsy will constrict to 1% pilocarpine
Slit lamp biomicroscopy — look for segmental iris sphincter palsy (vermiform movements)
14. ECG
- Not routinely indicated for isolated Adie's pupil
- Consider if autonomic dysfunction is suspected (evaluate for heart rate variability abnormalities)
15. Assessment
Adie's pupil is a benign, typically unilateral condition resulting from postganglionic parasympathetic denervation of the iris sphincter. The classic triad of Holmes-Adie syndrome includes tonic pupil, diminished deep tendon reflexes, and segmental anhidrosis. [2] Over time, the affected pupil may become smaller than the contralateral pupil as aberrant reinnervation occurs. The condition may become bilateral at a rate of ~4% per year.
Key clinical pearl: The critical distinction is between Adie's pupil and a pupil-involving CN III palsy. A dilated pupil from CN III palsy is virtually never isolated — it is always accompanied by some degree of ptosis and/or extraocular muscle dysfunction. [2] An isolated dilated pupil with no ptosis and full eye movements is Adie's until proven otherwise.
16. Treatment Plan
- Reassurance — this is a benign condition in the idiopathic (Holmes-Adie) form
- Dilute pilocarpine (0.125%) drops as needed for symptomatic blurred vision or photophobia [1]
- Reading glasses for accommodative difficulty
- Treat the underlying cause if a secondary etiology is identified (e.g., antibiotics for syphilis, IVIg for GBS/Miller-Fisher) [3][5]
- No surgical intervention is indicated
- Sunglasses for photophobia
17. Disposition
- Discharge from the ED is appropriate for classic, isolated Adie's pupil with confirmatory dilute pilocarpine test, no ptosis, full extraocular movements, and no neurologic deficits
- Admission/urgent workup if:
- Any ptosis or extraocular movement limitation (cannot exclude CN III palsy → emergent vascular imaging) [4]
- Bilateral tonic pupils with areflexia, ataxia, or oropharyngeal weakness (Miller-Fisher/GBS) [5-6]
- Signs of systemic autonomic failure
- Ophthalmology or neurology referral for outpatient follow-up in confirmed cases
18. Follow Up / Return Precautions
- Follow up with ophthalmology or neurology within 2–4 weeks
- Return precautions: new ptosis, double vision, worsening headache, limb weakness, difficulty swallowing, gait instability
- Counsel that the condition is benign but may become bilateral over years
- Over time, the affected pupil may paradoxically become smaller than the normal pupil due to aberrant reinnervation
- Deep tendon reflexes may progressively diminish
- Expected course: Symptoms of photophobia and blurred vision often improve with time as the pupil gradually becomes smaller [2]
References
1. Adie's Pupil: A Diagnostic Challenge for the Physician. — Xu SY, Song MM, Li L, Li CX. Medical Science Monitor : International Medical Journal of Experimental and Clinical Research. 2022.
2. The Eye in Neurological Disease. — Miller NR, Newman NJ. Lancet. 2004.
3. Concurrent Tonic Pupil and Trochlear Nerve Palsy in COVID-19. — Ordás CM, Villacieros-Álvarez J, Pastor-Vivas AI, Corrales-Benítez Á. Journal of Neurovirology. 2020.
4. Adult Strabismus Preferred Practice Pattern®. — Dagi LR, Velez FG, Holmes JM, et al. Ophthalmology. 2024.
5. Acute Oropharyngeal Palsy Following Bilateral Adie's Tonic Pupils Associated With Anti-GT1a and GQ1b IgG Antibodies. — Murakami K, Kajimoto Y, Ito H. Internal Medicine. 2022.
6. Tonic Pupils With Acute Ophthalmoplegic Polyneuritis. — Keane JR. Annals of Neurology. 1977.
7. An Approach to Anisocoria. — Gross JR, McClelland CM, Lee MS. Current Opinion in Ophthalmology. 2016.
8. Bilateral Tonic Pupils: Holmes Adie Syndrome or Generalised Neuropathy?. — Bremner FD, Smith SE. The British Journal of Ophthalmology. 2007.
9. Dilute Pilocarpine Test for Diagnosis of Adie's Tonic Pupil. — Yoo YJ, Hwang JM, Yang HK. Scientific Reports. 2021.
10. Pupillary Response to Four Concentrations of Pilocarpine in Normal Subjects: Application to Testing for Adie Tonic Pupil. — Leavitt JA, Wayman LL, Hodge DO, Brubaker RF. American Journal of Ophthalmology. 2002.
11. Pharmacological Testing of Anisocoria. — Antonio-Santos AA, Santo RN, Eggenberger ER. Expert Opinion on Pharmacotherapy. 2005.