No significant differences in the postmortem interval in Myanmar and Japanese using vitreous potassium levels

Abstract

Objective : New international criteria for the estimation of the postmortem interval (PMI) in autopsy cases could be useful. At present, there is no published information comparing differences between people of different ethnic origin. To address this, we have carried out an investigation to see if there is any ethnic difference in the postmortem interval in autopsy cases involving Myanmar and Japanese populations estimated using the vitreous potassium (K + ) level in aqueous humor. Results : Estimation of the PMI from the vitreous K + level was investigated using 82 known PMI autopsy samples collected from various sources and backgrounds (e.g., age, sex, cause of death and ambient temperature) from Myanmar and Japanese subjects using a Copenhagen Radiometer (ABL system). The present study shows that raised vitreous K + levels (mean of right and left eyes) from 1 to 60 hr after death are linearly correlated with increased PMI and the regression line follows that of the vitreous K + levels correlated with PMI and show no significant difference between race (Myanmar, r = 0.93 and Japanese, r = 0.91), eyes (right, r = 0.92 and left, r =0.93), sex (male, r = 0.91 and female, r = 0.93) and age ( r = 0.89). The PMI from the vitreous K + levels of Myanmar and Japanese and their 95% limits of confidence was ±13.8 and ±12.7 hr, respectively. Conclusion: The above result shows that measurement of the vitreous K + level of aqueous humor helps in theestimation of PMI and it appears that there is no significant difference between the two ethnic groups studied. In addition, estimation of the vitreous K + level may be a useful international criterion for estimation of the PMIinautopsy cases.