Neuro-Ophthalmic
Horner Syndrome
Also known as: horner syndrome, acute horner, painful horner, ptosis miosis, dilation lag, carotid dissection pupil
Filed as: Urgent
Source-cited from the record's own evidence list. Clinical content programme led by Dr Ankit Mathur, PhD, Grad Cert Ocu Thera, B.S. Optom. How the clinical content is governed
Clinical decision support only
Overview
Interruption of the sympathetic supply to the eye, giving a smaller pupil with mild ptosis on the same side. The size difference is greater in dim light and the small pupil dilates slowly, which is the observation that separates it from a physiological difference. Pain in the head or neck alongside a newly noticed Horner pattern raises concern for carotid dissection and warrants emergency assessment.
Recognition
Symptoms: what patients report
- Recent anisocoria noticed in dim light.
- Mild ipsilateral lid droop.
- Headache or neck pain if painful Horner pattern.
- Possible ipsilateral facial symptoms or reduced sweating.
- Diplopia is not typical for isolated Horner syndrome, but concurrent Horner features with diplopia raise cavernous sinus, brainstem, or carotid-pathway concern.
Signs: what the examination shows
- Anisocoria greater in the dark.
- Small abnormal pupil with dilation lag.
- Mild ptosis.
- Facial anhidrosis may be present.
What OptoGuide™ covers for horner syndrome
- Pattern reasoning: what this combination of findings points to, and its differentiators
- Don't-miss risks and escalation triggers
- Management tiers with linked Australian therapeutics
- Referral urgency, specialty, and letter drafting
Sources
- Horner Syndrome — EyeWiki
- The Neuro-Ophthalmology Survival Guide (Pane, Miller & Burdon) — standard reference text
Standard texts: Kanski's Clinical Ophthalmology: A Systematic Approach, Oxford Handbook of Ophthalmology, Oxford American Handbook of Ophthalmology, Signs in Ophthalmology: Causes & Differential Diagnosis.