Correlative Factors for Traumatic Brain Injury in Combat Ocular Trauma

Traumatic brain injury (TBI) remains a significant source of disability for active duty service members in both deployed and training settings as well as those who have left active service. Service members with ocular trauma are at risk for a TBI and should be screened appropriately. Early detection results in treatment to minimize long-term sequelae which can often be debilitating. This study is the first to evaluate different combat-related ocular injuries and their associations with TBI.

A secondary analysis of existing data was conducted from a prospective study of patients who sustained combat ocular trauma (COT) during Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF) between 2006 and 2020. Clinical data of a total of 88 participants were gathered and each case reviewed, including patient demographics, injury-related factors, history of TBI, and treatments rendered. All cases were then categorized to compare COT (n = 13) versus COT-T (Combat Ocular Trauma associated with TBI; n = 75). The Fisher's exact test was completed for each category to assess for predictive factors of TBI within the ophthalmic trauma cohort. Odds ratios were calculated with their 95% CI.

When compared to COT, COT-T was significantly associated with closed globe injuries (56%; OR 4.24, 95% CI 1.08-16.67), blast injuries (89.3%; OR 3.72, 95% CI 0.93-14.9), multiple surgeries (89%; OR 2.51, 95% CI 0.57-11.08), anterior segment injuries (69.3%; OR 1.41, 95% CI 0.42-4.79), optic nerve injuries (24%; OR 1.05, 95% CI 0.26-4.25), orbital fractures (48%; OR 2.08, 95% CI 0.59-7.34), enucleation (17.3%; OR 2.52, 95% CI 0.300-21.08), the use of eye protection (68.6%; OR 2.18, 95% CI 0.57-8.32), and the need to undergo plastic surgery (78.7%; OR 2.30, 95% CI 0.66-8.02). Significant factors associated with COT included penetrating injury (30.8%; OR 0.027, 95% CI 0.07-1.08), posterior segment injuries (92%; OR 0.264, 95% CI 0.032-2.17), bilateral injuries (76.9%; OR 0.678, 95% CI 0.17-2.69), and bilateral blindness (7.7%; OR 0.857, 95% CI 0.092-7.99).

Patients who have sustained combat-related ocular injuries, specifically blast injury, anterior segment injury, or an orbital fracture, were noted to be more likely to have also sustained a TBI. However, of the evaluated variables in predicting the co-occurrence of TBI, only closed globe injury was identified as statistically significant. Service members with injuries requiring multiple surgical procedures, reconstructive plastic surgery, or enucleation of an eye were also more likely to be diagnosed with a TBI, but these variables were not found to be predictive of TBI among ocular trauma patients. The presence of eye protection was not protective against TBI. Further studies are needed to find significant predictors of TBI in combat ocular trauma patients to assist in the early and accurate detection of TBI.