Post Mortem analysis of electrolytes in vitreous humour to determine time since death

Background: It has been found that so many biochemical materials, including electrolytes, remain remarkablystable after death while others show varying degrees of change; hence, the analysis of electrolytes in vitreoushumour has great medico-legal importance.Method: 95 autopsies were studied by making a puncture 5–6 mm away from the limbus by using a 10 ml sterilesyringe and 20 gauze needles. Aspirated vitreous was poured into a rubber stopped vial. The collected fluid wassent to the biochemistry department for electrolyte analysis. The analysis was carried out using the iron selectiveelectrode method, and the results were noted and compared.Results: The PM interval for 27 cases (28.4%) was < 12 hours, 32 cases (33.6%) was between 12-24 hours, and36 cases (37.8%) was >24 hours. In the study of different electrolytes, the sodium chloride value remainedinsignificant, but the potassium value had a highly significant p value (p<0.001). The highest mean value ofpotassium 10.62 (±1.90) in accidental falls and least in snake bite deaths was 6.7 (±0.23).Conclusion: The present pragmatic study has proved that vitreous potassium is the single best parameter toestimate and predict post mortem death accurately.