Decrease in electrolyte after vitrectomy surgery may affect the results of forensic investigations using vitreous humor

TL;DR

This study shows that vitrectomy surgery lowers electrolyte levels in vitreous humor, which could affect forensic investigations.

Contribution

The study reveals that vitrectomy significantly reduces electrolyte concentrations in vitreous humor, a factor not previously well understood in forensic contexts.

Findings

Vitrectomized eyes showed significantly lower sodium, potassium, chloride, and magnesium levels compared to control eyes.

Electrolyte levels in vitrectomized eyes were not correlated with patient age or time between surgeries.

Lens status did not affect electrolyte concentrations in vitreous humor.

Abstract

Vitreous humor (VH) is used for postmortem biochemical studies because it is well protected in an uncontaminated state even after death. The goal of this research was to investigate electrolyte concentrations in the VH from human eyes with and without a history of vitrectomy surgery.

We analyzed the sodium (Na), potassium (K), chloride (Cl) and magnesium (Mg) concentrations from 34 VH samples from 34 patients. Eleven samples were from eyes with a history of vitrectomy, and the remaining 23 eyes had no history of vitrectomy. The correlations of Na, K, Cl and Mg concentrations with patient age, interval between first and second vitrectomy, and lens status (history of cataract surgery) were also evaluated.

The Na, K, Cl and Mg concentrations in VH from vitrectomized eyes were 134.1 ± 7.9 mmol/L, 3.7 ± 0.2 mmol/L, 99.7 ± 6.7 mmol/L and 0.59 ± 0.09 mmol/L, respectively; all were significantly lower than the corresponding concentrations in VH from control eyes (lower by 5.0%, 11.0%, 11.7%, and 22.6%, respectively). Na, K, Cl and Mg concentrations in VH from vitrectomized eyes did not show significant correlations with patient ages or the interval between their first and second vitrectomies. There were no significant differences in Na, K, Cl and Mg concentrations in VH between phakic eyes and intraocular lens-implanted eyes.

With the increasing number of vitrectomies being performed, it is necessary to consider the history of vitrectomy when using a subject’s VH in forensic examination.

The online version contains supplementary material available at 10.1186/s12886-024-03445-2.

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