Concussion and its visual consequences was the focus at the recent National Australasian College of Behavioural Optometrists conference in Melbourne.
Dr Neera Kapoor described visual symptoms which can be the sequelae of previous head trauma, such as concussion, whiplash, acquired brain injury and stroke. Often clients present weeks, months or even years after injury, with symptoms they do not connect with their head trauma.
Dr Neera explained the visual system can be affected by brain trauma, primarily because 50% of the cranial nerves impact visual function directly or indirectly. It is important to consider the complexity of the visual cortex, with neurons from the brainstem nuclei of the cranial nerves traversing four different cortical lobes. Additionally, the mid-brain and the cerebellum, where a lot of the ‘how to’ of functioning is stored, can be impacted.
Dr Neera presented papers reviewing the occurrence of vision deficits in traumatic brain injury in a retrospective study of 160 patients.1,2 The most common deficit was convergence insufficiency (56.3%), followed by saccadic deficit (51.3%), accommodative insufficiency (41.1%), visual field scattered relative defects (38.7%), strabismus at near (25.6%) and third nerve palsy (6.9%). Other more recent studies have found slightly lower, but similar occurrence rates.3
Examining these clients requires a thorough binocular vision workup. As well as an assessment of ocular motor motility, workups need to include assessment of pursuits, saccades and fixation ability. These are becoming routine tests within hospitals.
Even a mild impact can affect the functioning of cognitive, vestibular, ocular-motor or cervical systems, along with exacerbating or triggering expressions of anxiety, mood disorders and migraines. Consequently, examination techniques may need to be modified. Upon questioning, these clients will often report symptoms specific to visualvestibular dysfunction, including loss of balance, dizziness, vertigo and motion sickness.4 As a consequence, their visual symptoms may include eyestrain (51.9%), increased light sensitivity (49.4%), headaches with near tasks (44.4%) and blurriness during near tasks (43.8%).4
Dr Neera Kapoor discussed common treatment options and the need for considered referral to allied health professionals and engaged caregivers.
Sarah Sweeney is a director of RA Optometrists in North Brisbane.
References
- Ciuffreda KJ, Kapoor N, Rutner D, Suchoff IB, Han ME, Craig S (2007). Occurrence of oculomotor dysfunctions in acquired brain injury: a retrospective analysis. Optometry, 78: 155-61.
- Suchoff IB, Kapoor N, Ciuffreda KJ, Rutner D, Han ME and Craig S (2008). The frequency of occurrence, types and characteristics of visual field defects in acquired brain injury: a retrospective analysis. Optometry, 79: 259-65.
- Cockerham GC, Goodrich GL, Weichel ED, Orcutt JC, Rizzo JF, Bower KS and Schuchard RA; JRRD 2009 46 (6): 811-818.
- Craig SB, Kapoor N, Ciuffreda KJ, Suchoff IB, Han ME and Rutner D. Profile of selected aspects of visually symptomatic individual with acquired brain injury: a retrospective study. Journal of Behavioural Optometry 2008: 19 (1): 7-10.
