This blog post is based on a presentation by Dr. Danielle Kalberer for SUNY’s Residency Major Presentations Event. Dr. Kalberer is a completing her residency in Primary Eye Care/Vision Therapy and Low Vision Rehabilitation at the Northport VA Medical Center.
A concussion is defined as a type of traumatic brain injury (TBI) characterized by immediate and transient alteration in brain function resulting from mechanical force or trauma. This may include alteration of mental status and level of consciousness. Concussion damage may not be identifiable on imaging scans or routine neurological examination, and patients often present with sequelae days, weeks or even months after an incident.
Blast injury has become the hallmark of returning soldiers involved in Operation Iraqi Freedom (OIF) & Operation Enduring Freedom (OEF). It is estimated that half of OIF/OEF veterans have suffered some level of brain injury from explosions. Sports-related concussions are also increasing in incidence. According to the CDC, U.S. emergency rooms evaluate over 130,000 youth sports-related TBI incidents (including concussions) per year. Of course, football is the first sport that comes to mind in any concussion discussion, but MANY sports are involved: soccer, lacrosse, wrestling, hockey, baseball and softball, just to name a few.
Trauma compromises brain function via 2 mechanisms: primary and secondary. Primary injury involves damage to neuronal axons via shearing, tearing and mechanical forces from the trauma. This “diffuse axonal injury” typically involves large portions of the brain and therefore causes deficits in many brain functions, including visual processing. Secondary injury results from metabolic/biochemical mechanisms that are triggered by the primary event. Susceptibility of the visual pathways can lead to impairment of basic tracking, scanning, accommodation, vergence and visual processing skills. These alterations in structure and function that can cause the symptoms typically associated with post-concussion vision syndrome: inability to sustain comfortable near-vision along with headache, diplopia, asthenopia, defocus, re-reading etc.
Optometric evaluation is the first step in helping these patients recover visual function and enhance their overall rehabilitation. A focused yet comprehensive examination will consider all the visual skills which may be impaired after a brain injury. Optometric management will often begin with the most appropriate spectacle prescription, which may incorporate prism, tints, and/or occlusion. Management will then go on to consider other options, including vision therapy. Ciuffreda and Kapoor have done extensive work with brain injured patients. Their research has shown significant improvements in visual function, especially oculo-motor skills, resulting from vision therapy. These improvements carried over to improvements in their ability to perform activities of daily living (ADLs). This series of blog posts and the hashtag party is aimed at raising awareness of brain injury and its consequences, because not all wounds are visible. We need to look harder for the invisible injuries and help these patients heal. Optometric evaluation and rehabilitation is an essential part of the multidisciplinary needs of patients recovering from a traumatic brain injury.