Vitreous humor in the evaluation of postmortem blood ethanol concentrations

Many studies have been published comparing blood (B) ethanol (EtOH) and vitreous humor (VH) EtOH concentrations. We conducted a similar study of routinely collected specimens to determine (1) whether the reported average VH/B ratios are consistent, (2) the percentage of cases with VH/B ratios outside of the expected range, and (3) the magnitude of B EtOH that can be associated with negative VH EtOH (less than 0.01 g/dL). VH EtOH less than 0.01 g/dL was associated with 41 specimens; 34 specimens had B EtOH less than 0.03 g/dL while a B EtOH as high as 0.12 g/dL was measured. For B EtOH less than 0.10 g/dL, 67% had VH EtOH within 0.02 g/dL of B EtOH (N = 101). For B EtOH greater than or equal to 0.10 g/dL, the VH/B EtOH ratio ranged from 0.10 to 1.91; the mean ratio was 1.17 and the median ratio was 1.18 (N = 205); and 64% had a ratio between 1.00 and 1.39. Vitreous humor can be used to facilitate understanding the significance of postmortem blood EtOH concentrations.