mydriasis = pupil dilation #opthal see also: [[pupil exam]], [[Relative afferent pupillary defect|RAPD]], [[anisocoria]], [[Diplopia]] **mnemonic:** SAW - sympathetic toxicity - [[Anticholinergic toxicity]] - [[Serotonin Syndrome]] - withdrawal syndromes **Traumatic causes** - traumatic mydriasis (blunt injury to iris sphincter and dilator muscles) - [[Lateral canthotomy|orbital compartment syndrome]] - (from RAPD) - [superior orbital fissure fracture](https://eyewiki.org/Superior_Orbital_Fissure_Syndrome) - fixed dilated pupil, not RAPD. also ophthalmoplegia, ptosis - optic nerve injury - subfalcine/uncal herniation - [[Vitreous haemorrhage]] - from RAPD - [[Retinal detachment]] - from RAPD **features of a third nerve palsy:** ![[Pasted image 20240802221201.png]] - ptosis - down-and-out pupil - mydriasis - failure of light reflex (but consensual constriction of the opposite eye is intact) - failure of accommodation