Objective Binocular Pupillometer

Checking pupils for an RAPD is an important part of the comprehensive eye exam, and is recommended in the AAO’s Preferred Practice Patterns® for POAG suspects and patients, however the swinging flashlight method is difficult for humans to do well, and even more difficult and time consuming to accurately quantify.

Importantly, there is evidence that even subtle RAPDs may be clinically significant. EyeKinetix makes it easy to accurately and objectively assess RAPDs and physiological anisocoria. 

Clinical Applications

Routine eye exams
POAG suspects and patients1
3rd cranial nerve palsies 

Optic nerve, retinal or cerebral vascular disease,
tumors, amblyopia

Multi-focal lens fittings

1. Pupil testing is recommended by the AAO and AOA
EyeKinetix is not cleared for the specific diagnosis of any condition.

Clinical Benefits

May aid in the detection of vision or even life-
threatening disorders

Accurately measure and
document physiological anisocoria

Objective: improve your confidence in routine and
subtle APD assessment

Detailed, objectively quantified documentation of
the presence or absence of an APD


FDA Listed | CPT Code 95919
Health Canada Licensed
CE Mark pending

A 21st century alternative to a 19th century test.

Konan Medical is the only company dedicated to advancing objective binocular pupillary testing technology for ophthalmology and optometry.

The EyeKinetix pupillometer utilizes high-definition video cameras under infrared conditions to record the bilateral pupil responses to monocular visual stimuli.

Unlike human observers that only see one pupil reflex at a time, EyeKinetix simultaneously records both direct and consensual pupillary light reflexes.

Easy, objective, quantitative, delegated, reimbursable; an order of magnitude more detailed than the finest human observer.

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Relative Afferent Pupillary Defect (APD/RAPD)

The APD is a measure of asymmetry which may occur with optic nerve, retinal, or cerebral vascular disease, and amblyopia, specifically when the disease or disorder is presenting asymmetrically. Pupil testing is a required part of a comprehensive eye examination, historically performed as a subjective observation (SFM), and considered by many clinicians as difficult to perform well.

Examples of disorders that may cause an APD:

  • Glaucoma

  • Amblyopia

  • Optic neuritis / MS

  • Optic nerve tumor

  • Optic nerve infections or inflammation

  • 3rd cranial nerve palsies

  • Retinal detachment

  • Intraocular tumor

  • Severe macular degeneration

  • Retinal infection

  • Alzheimer's

  • Autism

  • Brain tumors

  • Parkinson’s

  • Traumatic optic neuropathy


Visibility of Pupils Through Grey Absorptive Lenses

This simulation demonstrates how the pupils become difficult to see when neutral density filters are used to quantify an APD. 

Note that an APD of 0.3 light log units, which is considered subtle, means the affected eye 'sees' 50% less light than the unaffected eye. 

The RAPDx® Test

A differential assessment of the mean of the right eye stimulated responses versus the mean of the left eye stimulated responses are compiled as the “RAPDx Score”.

The RAPDx score illustrated here indicates that the left eye sees less light (i.e. has the weaker response) and the averaged score is recorded as 0.53 (constriction amplitude differential) in this example.

Assessed independently as being comparable to the swinging flashlight method when quantified using neutral density filters.

NOTE: Pharmaceutical agents including prescribed, OTC, recreational drugs and abused substances, as expected, may affect pupil reflexes and their measures.

Scotopic-Photopic Pupil Measurements + IPD

The low-high luminance test for pupil sizes is intended to document pupil sizes from very low light to bright conditions as approximate scotopic and photopic conditions.

Pupil dimensions, inclusive of asymmetry of pupil sizes can be helpful for functional pupil assessment, as well helping provide better understanding the contributions of optic zone dimensions in refractive surgery and complex multifocal IOl and contact lens selection.

The RAPDx score provides a highly sensitive and specific assessment of the RAPD compared to the swinging flashlight method. It is easily used by ancillary personnel as part of the screening of patients and is a powerful tool for clinicians needing to identify, confirm and quantify relative afferent pupillary defects
Nicholas J. Volpe, MD

Chairman, George S. and Edwina Tarry Professor in Ophthalmology 
Northwestern University, Feinberg School of Medicine