Checking pupils for RAPDs 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 subtle RAPDs may be clinically significant.

The RAPDx score provides a highly sensitive and specific assessment of the RAPD as tested by 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, Department of Ophthalmology, Northwestern University, Feinberg School of Medicine

A 21st Century Alternative to a 19th Century Test

EyeKinetix 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 eye reflex at a time, EyeKinetix simultaneously records both direct and consensual pupillary light reflexes.

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


Historical Methods:  The “Swinging Flashlight Method”

With origins stemming from the 19th century, this manual and subjective method of detecting an RAPD is commonly known to be difficult to perform well, under the best of circumstances. Although known to be an important physical sign, many well intention-ed doctors report little incidence – not because the sign is not present, but because it is difficult or impossible to detect and it is rarely quantified.


A Perfect Storm

Confounding issues such as minimum contrast (dark iris + black pupil + dark room), anisocoria, misshapen pupils and the lack of standardized light intensity conspire to make the swinging flashlight test even more challenging.

RAPDx Score

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” Signature

EyeKinetix pupillography provides 6 key measurements that make up the fundamentals of the pupil response “Signature”.

  • Resting pupil diameter
  • Latency, onset of constriction
  • Velocity of constriction
  • Amplitude of constriction
  • Latency, maximum constriction
  • Velocity of recovery

This is important new information that clinicians rarely collect reliably or at all.


Objective Pupil Assessment

Digital imaging of differential pupil function. Simple for technicians to acquire relevant clinical data.


Dark iris, dark pupil, dark room

The Marcus Gunn sign is a difficult test to perform well.  EyeKinetix easily measures asymmetry in the some of the most challenging conditions.

RAPDx Score

A mathematic assessment of direct and consensual pupil responses between right and left eyes.  Humans cannot simultaneously visualize and compare right versus left or consensual vs direct responses.


Easy Reporting

Beautiful reporting drills down to remarkable detail that humans simply cannot observationally divine.