Postmortem vitreous sodium and chloride elevate after 1 hour and magnesium after 2 hours in bovine eyeballs immersed in salt water

Background Postmortem vitreous sodium (Na) and chloride (Cl) are good ancillary tests in diagnosing salt-water drowning. Vitreous Na and Cl appear to elevate from salt-water drowning and immersion, whereas vitreous magnesium (Mg) appears to be unaffected by drowning, but elevates from immersion. The relative changes of these electrolytes during salt-water immersion are unknown, particularly with shorter immersion times. Understanding the relative changes may aid in the interpretation of vitreous electrolytes in bodies recovered from salt water. Aim The aim of this study was to compare the changes of vitreous Na, Cl, and Mg when immersed in salt water. Methods Bovine eyeballs were randomized into 2 groups (submerged in salt water and control). The vitreous Na, Cl, and Mg from 6 eyeballs were measured from each group (without replacement) at 1, 2, 4, and 6 hours. Results There were no statistically significant elevations in bovine vitreous Na and Cl for up to 1 hour and vitreous Mg for up to 2 hours. Conclusions Bovine vitreous Na and Cl elevate earlier than Mg when immersed in salt water. Assuming similar physical properties, an elevation in vitreous Mg in bodies immersed in salt water indicates the immersion effects of causing raised vitreous Na and Cl have started.