Estimation of time since death from potassium ion concentration in vitreous humour

Abstract

Abstract: Introduction: Time since death (TSD) also called, as post-mortem interval is an important element in investigation of crime and court trial. The large volume, easy accessibility, resistance to bacterial degradation and relatively inert nature makes the vitreous
humour to be the most suitable for chemical analysis. Lactic acid, hypoxanthine and potassium are the common parameters studied in vitreous humour. We aimed to study the change in concentration of potassium in the vitreous humour for estimation of time since
death. Material and Methods: This is a cross-sectional, hospital based study conducted in the Index medical college and hospital, Malwanchal University, Indore, from April 2019 to August 2023. All deceased cases with known time of death which were brought to mortuary were included in the current study. Body with previous ocular injury or surgery, bodies with extreme decomposition, posterior segment diseases and paediatric cases <less than 12 years of age were excluded. A total of 120 cases could be included. The collected data was tabulated in MS excel 2020 and analysed with SPSS software, version 20. Results: Mean age of deceased cases was observed 38.71±23.24 years with range from 13-77 years. Male: Female ratio in this study was 2.53:1. The most important cause of death among them was found to be ‘unclassified death’ which was followed by trauma. Mean time since death calculated from potassium levels in vitreous humour was found to be 12.7±7.62 hours and that from police or hospital records was 12.0±8.10 hours and the difference between two was non-significant. Also, a positive significant correlation was found between TSD using potassium level and TSD as per police or hospital records. In this study, a linear relation was found between potassium level and time since death