Review: Emerging Eye-Based Diagnostic Technologies for Traumatic Brain Injury.

The study of ocular manifestations of neurodegenerative disorders, Oculomics, is a growing field of investigation for early diagnostics, enabling structural and chemical biomarkers to be monitored overtime to predict prognosis. Traumatic brain injury (TBI) triggers a cascade of events harmful to the brain, which can lead to neurodegeneration. TBI, termed the "silent epidemic" is becoming a leading cause of death and disability worldwide. There is currently no effective diagnostic tool for TBI, and yet, early-intervention is known to considerably shorten hospital stays, improve outcomes, fasten neurological recovery and lower mortality rates, highlighting the unmet need for techniques capable of rapid and accurate point-of-care diagnostics, implemented in the earliest stages. This review focuses on the latest advances in the main neuropathophysiological responses and the achievements and shortfalls of TBI diagnostic methods. Validated and emerging TBI-indicative biomarkers are outlined and linked to ocular neuro-disorders. Methods detecting structural and chemical ocular responses to TBI are categorised along with prospective chemical and physical sensing techniques. Particular attention is drawn to the potential of Raman spectroscopy as a non-invasive sensing of neurological molecular signatures in the ocular projections of the brain, laying the platform for the first tangible path towards alternative point-of-care diagnostic technologies for TBI.

Determining the effect of ocular chemical injuries on topical drug delivery.

Ocular chemical injuries (OCIs) commonly cause ocular damage and visual loss and treatment uses topical therapies to facilitate healing and limit complications. However, the impact of chemical injury on corneal barrier function and treatment penetration is unknown. Therefore, the aim of this study was to determine the effect of OCI on drug penetration and absorption. Porcine corneal explants were used to assess histological damage, electrical resistance, and the trans-corneal penetration/corneal adsorption of reference compounds (sodium fluorescein and rhodamine B) and dexamethasone. Corneal explants were injured with either 1 M sulfuric acid, or 1 M sodium hydroxide. Dexamethasone penetration was measured using high-performance liquid chromatography (HPLC) and that of fluorescein and rhodamine using fluorescence. Dexamethasone corneal adsorption was measured using enzyme-linked immunoabsorbant assay (ELISA). Both acid and alkaline injuries reduced trans-corneal electrical resistance. NaOH injury increased hydrophilic fluorescein penetration (NaOH 8.59 ± 1.50E-05 cm.min-1 vs. Hanks' Balanced Salt Solution (HBSS) 1.64 ± 1.01E-06 cm.min-1) with little impact on hydrophobic rhodamine B (1 M NaOH 6.55 ± 2.45E-04 cm.min-1 vs. HBSS 4.60 ± 0.972E-04 cm.min-1) and dexamethasone penetration (1 M NaOH 3.00 ± 0.853E-04 cm.min-1 vs. HBSS 2.69 ± 0.439E-04 cm.min-1). By contrast, H2SO4 decreased trans-corneal penetration of hydrophilic fluorescein (H2SO4 1.16 ± 14.2E-07 cm.min-1) and of hydrophobic dexamethasone (H2SO4 1.88 ± 0.646E-04 cm.min-1) and rhodamine B (H2SO4 4.60 ± 1.42E-05 cm.min-1). Acid and alkaline OCI differentially disrupted the corneal epithelial barrier function. Acid injury reduced penetration of hydrophobic dexamethasone and rhodamine B as well as hydrophilic fluorescein, which may translate clinically into reduced drug penetration after OCI, while alkaline injury increased fluorescein penetration, with minimal effect on dexamethasone and rhodamine B penetration.

Prolonged deployed hospital care in the management of military eye injuries.

BACKGROUND/OBJECTIVES: Prolonged hospital care is described as deployed medical care, applied beyond doctrinal planning timelines and military medical planning envisages that in future conflicts, patients will have to be managed for up to 5 days without evacuation to their home country. We aimed to investigate the effect of prolonged hospital care on visual outcomes in the management of open and closed globe injures. METHODS: We conducted a retrospective cohort study in the setting of British military operations in Afghanistan. We included consecutive UK military patients with ocular trauma evacuated from Afghanistan between December 2005 and April 2013. We assessed outcome using best-corrected visual acuity (VA) 6-12 months after injury. RESULTS: All patients were male, with a mean age of 25. Outcomes adjusted for ocular trauma score (OTS) at presentation were similar to previous reports of military ocular trauma. The mean time to arrival at a centre with an ophthalmologist was 1.74 days. Both patients with penetrating open globe injuries and patients with hyphaema and an OTS of 3 or less displayed an association between worsening 6-12 month VA and time between injury and repair or assessment by an ophthalmologist. CONCLUSION: Time to specialist ophthalmic care contributes to outcome after military open and closed globe injuries, supporting deployment of ophthalmologists on military operations.