Abstract
Purpose :
The number of military soldiers experiencing single or repeated blast injuries has increased with the development of explosive devices. Many of them suffer from visual deficits resulting from blast-induced eye and brain injury. The importance of studying visual deficits has been noticed due to their significant lifelong effects. However, the blast-induced visual deficit mechanism, which helps to diagnose and treat, is not fully understood because of its difficulty mimicking an open-field blast environment. In this study, we evaluated retinal pathophysiology following repeated blast exposure to the eye and brain using a custom-built advanced blast stimulator (ABS) reproducing an open-field blast environment.
Methods :
The left side of the eye and head of WT mice (C57BL/6J, 12 weeks old) were exposed to three consecutive air blast shocks with a peak overpressure of 138 KPa using a custom-built ABS, and unexposed age-matched mice served as control. At 3 days after blast injury, the left eyes of blast-exposed and control mice were harvested, and TUNEL assay was performed. At 6 weeks after blast exposure, visual function was examined by visual acuity, pattern-evoked electroretinography (PERG) and positive scotopic threshold response (pSTR), and retinal sections were prepared for immunohistochemistry.
Results :
At 3 days after blast injury, increased TUNEL positive cells in the ganglion cell layer were observed in blast-exposured retina. At 6 weeks after blast injury, there were significant reductions of visual acuity, PERG, and pSTR in blast-exposed mice compared to those in control mice, accompanied by a significant reduction of retinal ganglion cells.
Conclusions :
Our study demonstrates that repeated blast exposure on the eye and brain results in severe pathophysiological damage in the retina. The blast injury model with ABS mimicking open-field blast is reproducible and may facilitate the study of biomarkers for diagnosis and neuroprotective mechanisms to explore therapeutic targets in sodiers suffering from blast injuries.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.