DR. GIFFORD JONES
“I’ve just seen two images of the same person on the TV screen,” my mother complained years ago. She had developed double vision (DV). But what causes DV? And how many children suffering from attention deficit hyperactive disorder (ADHD) are being medicated when the trouble is in their eye?
Dr. Patrick Quaid, an expert in double vision, is head of the Guelph Vision Therapy Centre.
He says double vision must be taken seriously as a diagnosis can range from brain tumour, concussion, inflammation of an artery, to simple dysfunction of ocular muscles. Fortunately, when adults notice DV, they know something is wrong that demands quick attention.
But Quaid says children with ADHD often get either a delayed diagnosis or no diagnosis of ocular disorder. Doctors treating a child with ADHD rarely consider arranging for an eye examination to detect ocular malfunction.
The most commonly encountered abnormality is ‘convergence insufficiency’, or difficulty keeping the eyes tuned when reading.
These children have eyes that do not work in unison due to an imbalance of muscle control. Consequently, they see double when reading, frequently lose their place, find reading frustrating and shy away from it, which affects their learning.
Quaid states ironically parents of children with convergence insufficiency may be told their child has 20/20 vision by a regular eye test.
Convergence insufficiency is not rare.
Quaid claims one in 10 people has some sort of eye teaming problem. But what is shocking, and generally unknown, is children affected with ADHD have three times greater risk of convergence insufficiency. All the more reason that these children must see an eye doctor who is cognizant of eye teaming abnormalities.
Quaid adds doctors who are looking for a quick fix often place ADHD children on Ritalin, or some other medication, without arranging for a oculomotor workup.
During an interview, Quaid discussed another pressing problem that concerns many parents, ‘Post-Trauma Vision Syndrome’ (PTVS). Today, brain concussions are becoming a fact of life for children and adults involved in sports.
Moreover, bruised brains can result in neurological and ocular abnormalities despite normal results from MRI and CT scans.
Quaid, ahead of the times, has sage advice for those who intend to engage in contact sports.
Be sure to get a baseline test for binocular vision function before engaging in contact sports. This is important as those who already have binocular vision dysfunction, and may not realize it, will likely suffer even greater eye teaming issues should they suffer a subsequent concussion.
Just how many children in this country are being diagnosed with ADHD when they in fact suffer from subtle forms of double vision is unknown.
The difficulty for parents is that children will usually not complain of problems with eye teaming as they may not be aware of what to report.
This may result in misdiagnosis. Fortunately, the Guelph Vision Therapy Centre is one of the few places that offers a comprehensive approach to ADHD and eye teaming problems. This involves close interaction between eye doctors with experience in binocular vision disorders, psychologists, speech and language pathologists and occupational therapists.