What does quantitative pupillometry with neos® measure?

neos® measures afferent and efferent pupillary function using standardized stimuli and reports quantitative parameters, including an RAPD neoscore derived from an automated swinging flashlight test.

How long does quantitative pupillometry take?

neos® quantitative binocular pupillometry runs an automated test sequence in under three minutes.

Who is intended to use neos®?

neos® is intended to be used by health care professionals in clinical settings (e.g., ophthalmology, optometry, neurology). In the EU/CH/UK, neos® results support diagnosis and monitoring; in the US, neos® provides objective, quantitative measurements.

neos® quantitative pupillometry

neos^® systematically presents visual stimuli to both eyes individually and together, measuring the resulting eye movements and pupillary changes of each eye, and charting this data in an examination report.

Efferent pupillary function can be assessed quickly, reliably, and objectively in an immersive VR environment with neos^®. The head-mounted display minimizes the influence of ambient light, removing the need to darken an examination room.

neos^® continuously measures the pupil size of both eyes in real-time with high precision. This sequence is repeated to ensure consistent and meaningful results.

Pupillography helps to quickly appreciate pupil dynamics in addition to measurement values

Acute Horner Syndrome identified by Pupillography revealing Internal Carotid Artery Dissection

Victoria Borisova, Muriel Dysli

European Neuro-Ophthalmology Society (EUNOS) Meeting, 2026
doi: 10.1080/01658107.2026.2651025View publication

Study details

Introduction

Acute anisocoria with ipsilateral ptosis, particularly when the pupillary asymmetry is greater in the dark, should raise suspicion for
Horner syndrome and prompt urgent evaluation for potentially life-threatening causes such as internal carotid artery (ICA) dissection. Early recognition in the neuro-ophthalmology setting is critical to prevent cerebral ischemic complications.

Case Report

A 38-year-old woman presented with a smaller right pupil and mild right ptosis for 5 days, accompanied by right neck pain and facial pressure. She had recently been physically active. Exam showed right miosis (more pronounced in dim light) with briskly reactive pupils and mild ptosis.
Pupillography (neos® system) demonstrated a clear right-sided dilatation lag, providing objective confirmation of oculosympathetic dysfunction. Pharmacological testing for Horner syndrome was not pursued because the lopidine test could not be realiably interpreted in cases of recent onset.

Contrast-enhanced computed tomography (CT) of the head and CT angiography (CTA) revealed a short-segment mural hematoma consistent with right ICA dissection, extending from the distal cervical segment to the transition into the petrous segment. No intracranial hemorrhage or cerebral ischemia was detected.

Management

The patient was admitted for monitoring and started on antiplatelet therapy with Aspirin 100mg.
Cervical artery duplex ultrasound showed no significant stenosis
With no signs of connective tissue disorder and a history of intense physical activity, the dissection was considered likely provoked.
MR angiography (MRA) at 6-month follow-up showed normalization of the vessel lumen.

Discussion

Acute Horner syndrome with ipsilateral neck/facial pain is a classic red flag for ICA dissection.
As pupillary findings may be subtle, objective testing (e.g., pupillography) can support clinical suspicion, expedite emergency imaging, and occasionally a pharmacologic testing is not necessary any more due to the characteristic appearance with dilation lag in pupillography.
Prompt vascular imaging with CTA or MRA is essential for diagnosis.
Early antithrombotic therapy (antiplatelet or anticoagulaton, depending on clinical context) reduces thromboembolic and ischemic risk.
Painful acute Horner syndrome should be treated as an emergency until ICA dissection is excluded.