Purpose. The purpose of this study was to determine the frequencies of visual impairment and dysfunction among combat-injured Polytrauma Rehabilitation Center (PRC) inpatient and Polytrauma Network Site (PNS) outpatient military personnel with traumatic brain injury (TBI).
Methods. A retrospective analysis of data from vision screenings of 68 PRC-inpatients with moderate to severe levels of TBI and 124 PNS-outpatients with mild TBI at the VA Palo Alto Health Care System was conducted.
Results. Eighty-four percent of PRC-inpatients and 90% of PNS-outpatients had TBIs associated with a blast event. The majority of patients in both the PRC and PNS populations had visual acuities of 20/60 or better (77.8% PRC, 98.4% PNS). Visual dysfunctions (e.g., convergence, accommodative, and oculomotor dysfunction) were common in both PRC and PNS populations. In the PRC-inpatient population, acuity loss of 20/100 to no light perception (13%) and visual field defects (32.3%) were found. In the PNS-outpatient population, acuity loss of 20/100 to no light perception (1.6%) and visual field defects (3.2%) were infrequently found. In both the PRC and PNS populations, visual field defects were more often associated with blast than non-blast events.
Conclusions. Blast events were the most frequent mechanism of injury associated with TBI in combat-injured servicemembers. The vision findings suggest that combat troops exposed to blast with a resulting mild TBI are at risk for visual dysfunction, and combat troops with polytrauma injuries are at risk for visual dysfunction and/or visual impairment. The visual consequences of such injuries necessitate further study and support the need for appropriate evaluation and treatment in all severities of TBI.