The two eyes can yield different vitreous drug concentrations in the same autopsy. In one MDPHP case, right vitreous contained 1,846.45 ng/mL and left vitreous 2,568.01 ng/mL. The authors proposed partial coagulation as an explanation for the higher left-sided result, but did not experimentally establish the cause of the difference.
What was sampled?
Croce and colleagues investigated one 30-year-old man found dead with a history of cocaine use. The estimated postmortem interval was three to four hours. He had last been seen alive 24 hours before discovery, which did not supply an exact ingestion time.
Autopsy collection included central and peripheral blood, separate right and left vitreous humor, urine, gastric contents and hair. The report did not identify the exact peripheral blood site or provide a controlled serial vitreous collection sequence.
The measured concentrations differed by specimen
Targeted LC–MS/MS measured MDPHP at 1,639.99 ng/mL in central blood and 1,601.90 ng/mL in peripheral blood, alongside the two vitreous values. Urine contained 12,954.13 ng/mL and gastric contents 3,028.54 ng/mL.
These were concentrations in different biological compartments. A higher urine or vitreous result did not represent the same measurand as a blood concentration, and the study did not validate conversion equations between them.
The liquid-specimen procedure used 200 µL aliquots, acetonitrile treatment and LC–MS/MS. The report listed a quantification limit of 0.5 ng/mL, recovery of 78.8% and ion suppression of −20.4%. Those figures describe the reported analytical method; they do not quantify the contribution of coagulation or uneven sampling to the two-eye difference.
What did the coagulation explanation establish?
The authors suggested that partial coagulation of the left vitreous could explain its higher concentration. They did not report an experiment separating clot and fluid fractions, repeated standardized eye collections, or a series of comparable cases measuring that effect.
The explanation should therefore remain a hypothesis linked to this specimen’s condition. The case cannot establish a correction factor for coagulated vitreous or a normal right-to-left range for MDPHP.
Similar blood values did not measure antemortem change
The authors interpreted the similar central and peripheral blood concentrations as evidence against relevant redistribution. That was their assessment of this case. A single collection from two sites, however, did not directly measure the difference between the man’s predeath and postmortem blood concentrations.
There was no paired antemortem sample and no serial study showing how either blood or vitreous concentration changed. The short estimated interval also did not prove that redistribution or other postmortem change was impossible.
Why the result is useful without becoming a universal rule
The case supplies an example of MDPHP detection in both eyes and highlights the importance of recording specimen condition. It supports preserving laterality and keeping the two results separate, rather than silently averaging them into a supposedly definitive blood-equivalent value.
The study did not determine the dose, exact intake time or a threshold for impairment. Its probable poisoning conclusion incorporated the whole investigation; neither one eye’s concentration nor the discrepancy independently established cause of death.
For broader matrix limits, see vitreous drug screening compared with blood and why vitreous detection does not establish a blood concentration.
Primary source
Croce EB, Dimitrova A, Di Milia MG, et al. Postmortem distribution of MDPHP in a fatal intoxication case. Journal of Analytical Toxicology. 2025;49:137–141. doi:10.1093/jat/bkae092.
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