Accurate estimation of the postmortem interval (PMI) is an important research topic in Forensic Medicine,but all methods till now in use to determine it are to a degree unreliable. Vitreous humor of eye being relatively stable, less susceptible than other body fluids to rapid chemical changes and contamination, easily accessible and is suitable to estimate postmortem interval. Aim of the study: to assess the accuracy of vitreous potassium (K) level in estimating PMI. Material and Methods: This study was carried out on cases brought to the mortuary of Benha medicolegal department of Ministry of Justice, Qaluobyia, Egypt, during "March 2012 to October 2012". Vitreous humor samples were collected from the both eyes of deceased for determination of K levels. Actual postmortem interval was estimated according to the history and changes recorded in the cadaver. Results: the total number of cadavers was 120, 64.8% male and 34.2% female with male to female ratio (1.8:1). There was significant increase (P< 0.05) in the potassium concentration with increasing PMI. The average rate of increase of vitreous potassium was calculated as 0.10795mmol/L per hour. Moreover there is linear correlation between vitreous K and PMI. There was no significant effect for variation of gender, age and temperature on vitreous K level. There is a significant correlation between K levels and actual PMI from police records, hospital records and recorded postmortem changes. There is no significant statistical difference between actual and estimated PMI. Conclusion: Potassium level in the vitreous fluid increases significantly with increase in PMI and it can be used as a valuable indicator to estimate PMI accurately in cases of deficient information about this time from other methods. |
