Which vitreous humor biochemical marker is considered the MOST reliable for estimating time since death because it rises linearly and is least affected by decomposition?
- A Vitreous glucose
- B Vitreous potassium ✓
- C Vitreous urea
- D Vitreous lactate dehydrogenase
Correct answer: B. Vitreous potassium
Explanation
Vitreous potassium rises in a linear, time-dependent manner after death due to progressive membrane pump failure and intracellular potassium release. Multiple regression equations (e.g., Lange et al., Madea) use vitreous potassium to estimate postmortem interval. Vitreous glucose falls rapidly and is unreliable for TSD. Urea and LDH are affected by pre-existing disease and decomposition processes. Vitreous potassium remains the best biochemical marker for early TSD estimation.
Reference: The Essentials of Forensic Medicine and Toxicology (Narayan Reddy), 34th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.