PERRLA
Normal Pupillary Exam
Six checks in one glance — document on every neuro exam.
The board-friendly take on the neuro exam is that PERRLA documents the entire pupillary exam in six letters and you write it on every chart. Pupils Equal in size, Round in shape, Reactive to Light (direct and consensual), and Accommodation (constrict on near focus). Anisocoria, irregular shape, sluggish reaction, or a fixed dilated pupil all point at pathology — opioid toxicity, Horner's, third nerve palsy, herniation. AANP exam questions test what an abnormal PERRLA finding implies: pinpoint reactive pupils suggest opiates or pontine stroke, fixed dilated pupils suggest herniation or atropine, anisocoria with ptosis suggests Horner's syndrome. Document specifics, not just normal.
- PPupilsBaseline inspection — size in mm.
- EEqualBilateral, same size. Anisocoria >1 mm may be pathologic.
- RRoundRegular shape. Irregular = iris pathology (trauma, surgery, synechiae).
- RReactiveConstrict briskly to direct and consensual light.
- LLightBoth pupils shrink when either eye is lit (consensual response).
- AAccommodationBoth pupils constrict when focusing from far to near.
Clinical Context
Standard pupillary documentation across primary care, ED, and neuro exams. Abnormal findings have classic patterns: blown unilateral pupil = uncal herniation (emergent); pinpoint = opioid overdose; mid-position fixed = brainstem stroke; Argyll Robertson pupil (accommodates but doesn't react to light) = neurosyphilis.
AANP includes pupillary exam in acute neuro/ED stems — know which pattern points where. A quick PERRLA check catches elevated ICP, stroke, and tox in seconds.
Related Mnemonics
- CENTOR — Strep Pharyngitis Probability (Centor / McIsaac)
Sources
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