The Eye in Forensic Medicine: A Narrative Review

Abstract

The eye, with its distinctive anatomy, not only reflects a wide variety of diseases in life but also undergoes a myriad of post-mortem changes. Consequently, the eye has long been an area of interest in forensic science, primarily for the estimation of post-mortem interval and therefore the time of death and also for assistance in ascertaining the cause of death. There has been significant progress in the knowledge of ophthalmic forensic science using new technologies which have allowed further possibilities to arise where understanding of this field can assist the forensic pathologist. This review aims to highlight the current knowledge which exists in this field and also to identify important avenues for further investigation. Post-mortem changes of the eye along with its current applications and challenges will be discussed. These include the important areas of post-mortem iris biometrics, pupil size correlation with post-mortem interval, use of point-of-care technology on vitreous humor, and the use of ophthalmic imaging in pediatric abusive head trauma.

PMI estimation through metabolomics and potassium analysis on animal vitreous humour

“…In consideration of its peculiar anatomy and physiology, the eye has thoroughly been studied for forensic purposes [ 11 – 14 ]. In particular, vitreous humour (VH) has been a biofluid of choice for forensic purposes [ 15 ], being investigated through chemical, biochemical, toxicological, and metabolomic approaches to address not only the cause but also the time since death.…”

Post-Mortem Interval and Microbiome Analysis through 16S rRNA Analysis: A Systematic Review

“…Although in the forensic field the eye has been and is still widely studied, mainly for the estimation of the post-mortem interval [ 72 , 73 ], only one study among those examined in the review included the eye among the sampling sites [ 57 ]. This is difficult to explain, as the eye presents itself as an organ that is easily sampled given its location and being relatively anatomically well isolated from the body.…”

Aspectos médico-legais do olho

“…Um aspecto que pode ser observado é a manutenção da abertura ocular, pois, na morte encefálica, o reflexo de fechar os olhos está ausente após abertura passiva. (35) Em países como Japão, Austrália e Nova Zelândia, critérios avaliativos, como a não reatividade das pupilas bilateralmente (com diâmetros >4mm), são adotados, embora em países como Canadá, Estados Unidos e Reino Unido esta não seja uma exigência para o diagnóstico 44 . No Reino Unido, por exemplo, a exigência é de que as pupilas estejam fixas e não tenham reflexos mediante estímulos luminosos, que se apresentam como métodos de comprovação de morte encefálica, (36) sem necessariamente apresentar a necessidade de achados como os diâmetros pupilares, pois estes podem apresentar variações, como as encontradas em estudos que mostram a diferença de diâmetros médios de 6,1mm (desvio-padrão de ±1,1mm) durante o exame inicial e 6,4mm (desvio-padrão de ±1,1), sendo esses exames realizados com a diferença de 6 horas.…”

“…Além da concentração de potássio, também pode-se analisar a glicose vítrea, que pode indicar, por exemplo, hiperglicemia associada à cetoacidose diabética e hiperglicemia hiperosmolar não cetótica, que auxilia no diagnóstico da morte. (44)…”