More On ADHD and Vergence

Last September, our colleague Dr. Dan Fortenbacher blogged eloquently about why all children with ADD/ADHD or adverse academic behaviors should have a a binocular vision evaluation.  A research article published in PLOS One last month, Attention-Related Eye Vergence Measured in Children with Attention Deficit Hyperactivity Disorder by Puig and colleagues in Barcelona, bolsters this position.

PLOS One Graphic

The nature of the study has some resemblance to the T.O.V.A. (Test of Variables of Attention) in that computerized stimuli were used with the subjects pressing a button to indicate their response.  In this story, the experimental setup has the advantage of monitoring vergence angle and eye positions with minimal apparatus – an important consideration for children whose attention is easily drawn away from the task.  While fixating a center cross, subjects indicated covert attention to face targets, with their gaze monitored objectively by a Tobii Eye Tracker built into the computer so that nothing distracting was on their face or in front of their eyes.  The authors had previously published about successful use of this methodology in studying attention and vergence in adults.  This study compared children diagnosed with ADHD to a control group of children who did not have that diagnosis.

Tobii Eye Tracker

From the current article, here is a schematic of the vergence and task design.

ADHD Vergence PLOS One

The authors report that they observed a strong modulation in the angle of vergence and a difference between the cue conditions in the control group. However in the ADHD group a weak modulation in the angle of vergence was observed and no difference between the cue conditions was detected.

In discussing the clinical relevance of their findings, the authors note that because attention related vergence differs between controls and children with ADHD, evaluation of vergence during an attention task may be useful for the development of an observer independent tool for the diagnosis of ADHD.  They write:  “Furthermore, for people with binocular deficits, vision therapy increases the eyes’ convergence ability with eye-focusing exercises. Typically, these exercises include simple ‘pencil pushups’, computer vision therapy, or glasses with built-in prisms. It will be interesting to examine whether attention related vergence can be improved by vision therapy that employs purposed designed visual tests.”

Although Puig and colleagues are apparently not familiar with the breadth of vision therapy for CI beyond pencil pushups, computer vision therapy, or prism glasses, as employed for example in the CITT, their research supports a burgeoning worldwide interest in the interrelationships between vergence and ADHD.  This takes us to the doorstep of the CITT-ART, the design of which was recently introduced in Vision Development and Rehabilitation.  From a variety of angles, including performance in school, bringing attention to the interrelationships between vergence and ADHD stands to convert alot of sad and neutral faces to happy faces.


3 thoughts on “More On ADHD and Vergence

  1. Kid with attention problems deserve an evaluation for convergence insufficiency. In my experience, when a child with convergence insufficiency has good attention when being read to and poor attention for reading and writing, the attention problem may well disappear after vision therapy. this is especially true if the child already know how to decode. Children who listen poorly generally have other problems beyond the convergence insufficiency. This may be helped by vision therapy, but will definitely need a multidisciplinary approach.

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