Intermediate
Technical
IVT
light-near dissociation
Pupillary response pattern with absent light reflex but preserved near response.
Full Definition
An abnormal pupillary finding where pupils fail to constrict to direct light stimulation but maintain the ability to constrict during accommodation and convergence for near vision. Classic signs include Argyll Robertson pupils (neurosyphilis), Adie's tonic pupil, and Parinaud syndrome. The dissociation occurs due to differential anatomical pathways for light and near reflexes in the midbrain. Important clinical sign requiring systematic evaluation for underlying neurological conditions.
Usage
Usage note: Always hyphenate 'light-near' when used as a compound modifier; distinguish from RAPD in documentation.
In Context
- "Light-near dissociation was noted bilaterally, raising concern for neurosyphilis." — Neuro-ophthalmology examination
- "The unilateral light-near dissociation suggested an Adie's tonic pupil rather than a third nerve palsy." — Pupillary assessment report
Also known as
pupillary light-near dissociation
accommodation-convergence sparing
Contrasted with
normal pupillary response
Don't confuse with
relative afferent pupillary defect
Horner syndrome