Overview
These are bilateral small pupils that constrict when a patient focuses on a near object (accommodation is intact), but do not constrict when exposed to light. It is highly specific for neurosyphilis.
Presentation
Pupils are often irregular and small. A common mnemonic for remembering the features in an Argyll-Robertson Pupil (ARP) is Accommodation Reflex Present (ARP) but Pupillary Reflex Absent (PRA).
Causes
- Neurosyphilis – the most common cause
- Diabetic neuropathy
- Encephalitis
- Multiple sclerosis
