Variation of the intraocular pressure in relation to time of death: contribution to the determination of the true postmortem interval (PMI)

Introduction: Postmortem Interval estiamtion is a measure of singular importance in Legal Medicine. Due to its complexity, it needs objective evaluation in Forensic Pathology. Methods: In this study we propose the use of a bovine model to sytematically measure premortem and postmortem Intra-Ocular Pressure (IOP) as well as analyze its evolution with time as a possible non-invasive method to estimate PMI. A prospective, descriptive, observational study was carried out, using 12 cows. For the determination of the IOP, the aplanatic manual Perkins tonometer calibrated for bovines was used. The measurement of the IOP was done at establisehd post-mortem intervals. Results: The mean IOP at hour 0 in OD was 13.48 mm Hg and 13.59 mm Hg in OS with minimal variation between groups; at hour 30 hr, the IOP was 6.41 and 6.45 mm Hg in OD and OS respectively. We observed a decrease of the IOP in al leyes, directly related to the elapsed time of death. Discussion. The uniformity of the IOP estimations in relation to postmortem interval allows us to consider it as a valuable parameter for postmortem interval even several hours after death.Keywords: Postmortem Interval, IntraOcular Pressure, tonometry.