Anisocoria

Definition

• This is a difference of ≥ 0.4mm in pupillary diameters
• It is due to mydriasis if it is worse in bright light
• It is due to miosis if it is worse in the dark

Pharmacological causes of unilateral mydriasis

Ophthalmic causes of unilateral mydriasis

Neurological causes of unilateral mydriasis

Toxic causes of unilateral mydriasis

Iatrogenic causes of unilateral mydriasis

Other causes of unilateral mydriasis

Causes of unilateral miosis

References

1. Evans RW, Jacobson DM. Transient anisocoria in a migraineur. Headache 2003; 43:416-418. 
2. Heath Jeffery RC, Young B, Swann PG, Lueck CJ. Unequal pupils: understanding the eye's aperture. Aust J Gen Pract 2019; 48:39-42.
3. Ekici A, Caglar B, Kara O, Oto A, Kilic N. Rare causes of anisocoria: Ipratropium bromide and Angel's trumpet. North Clin Istanb 2021; 8:623-625.
4. Garstad LJ, Mygland Å, Ljøstad U. A woman in her 40s with anisocoria and unilateral facial flushing. Tidsskr Nor Laegeforen 2017; 137:40-42.
5. Shah J, Jiang A, Fekete Z. Anisocoria secondary to inadvertent contact with scopolamine patch. BMJ Case Rep 2017; 2017:bcr2017221677.
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Related checklists

• Tonic pupils
• Holmes-Adie syndrome (HAS)
• Ross syndrome
• Argyll Robertson pupil
• Harlequin syndrome
• Benign episodic unilateral mydriasis (BEUM)