“…The estimation of the PMI is crucial for medicolegal investigation, and after the publications of Sturner and Adelson in 1963, over the past fifty years several authors confirmed the PM linear increase of K+ concentration in VH. The most part of the authors did not report any differences of biochemical marker concentration among the two eyeballs in the same patient [10,11], and, apart from the common problem found in the literature due to the difficulty to find information related to pre-existing pathologies of the patient [12][13], the finding of a strict relation between analytes concentration of VH and serum confirms the results of our research and gives us the evidence of the good quality of the withdrawal procedure. Over the years, the importance of pre-analytical treatment was well discussed and several authors analyzed the problem of determining the analytes through automated systems, not validated for such biological fluids [9] and specifically not for the VH, actually affected by different matrix components; among the techniques used for the evaluation of the K+ concentration, capillary electrophoresis was validated by comparing results with flame photometry, even if in most papers the authors adopted automatized instruments validated for other biological fluids without comparing the results with a gold standard method of measurement of the electrolyte concentration [3,8,[14][15][16].…”