Photographic assessment of retinal hemorrhages in infant head injury: the Childhood Hemorrhagic Retinopathy Study

Ophthalmologic findings in abusive head trauma

A leading cause of death and disability in infancy is abusive head trauma (AHT) and there are common clinical signs that help to establish this diagnosis. Children diagnosed with AHT can have many ophthalmologic findings, including retinal hemorrhages, retinoschisis, subconjunctival hemorrhages, corneal injury, and globe rupture. If any such injuries are suspected, an ophthalmologic consultation, with indirect ophthalmoscopy, should be completed. In addition to a complete physical exam, a thorough history imaging, and lab work, should be obtained to investigate the etiology of ophthalmic pathology including accidental and systemic causes. In general, studies show that retinal hemorrhages that are multilayered, too numerous to count, and located from the posterior pole to the ora serrata are highly suspicious for abusive head trauma.

Identifying inflicted injuries in infants and young children

Child physical abuse is a common cause of pediatric morbidity and mortality. Up to half of all children presenting with abusive injuries have a history of a prior suspicious injury, suggesting a pattern of repeated physical abuse. Medical providers are responsible for identifying children with suspicious injuries, completing mandated reporting to child protective services for investigation, and screening for occult injuries and underlying medical conditions that can predispose to injuries. Early identification of inflicted injuries appropriate evaluations may serve as an opportunity for life-saving intervention and prevent further escalation of abuse. However, identification of abuse can be challenging. This article will review both physical exam findings and injuries that suggest abuse as well as the evaluation and management of physical abuse.

Retinodural haemorrhage of infancy, abusive head trauma, shaken baby syndrome: The continuing quest for evidence

The shaken baby syndrome was originally proposed in the 1970s without any formal scientific basis. Once data generated by scientific research was available, the hypothesis became controversial. There developed essentially two sides in the debate. One side claimed that the clinical triad of subdural haemorrhage, retinal haemorrhage, and encephalopathy, or its components, is evidence that an infant has been shaken. The other side stated this is not a scientifically valid proposal and that alternative causes, such as low falls and natural diseases, should be considered. The controversy continues, but the contours have shifted. During the last 15 years, research has shown that the triad is not sufficient to infer shaking or abuse and the shaking hypothesis does not meet the standards of evidence-based medicine. This raises the issue of whether it is fit for either clinical practice or for the courtroom; evidence presented to the courts must be unassailable. WHAT THIS PAPER ADDS: There is insufficient scientific evidence to assume that an infant with the triad of subdural haemorrhage (SDH), retinal haemorrhage, and encephalopathy must have been shaken. Biomechanical and animal studies have failed to support the hypothesis that shaking can cause SDH and retinal haemorrhage. Patterns of retinal haemorrhage cannot distinguish abuse. Retinal haemorrhages are commonly associated with extracerebral fluid collections (including SDH) but not with shaking. Infants can develop SDH, retinal haemorrhage, and encephalopathy from natural diseases and falls as low as 1 foot. The shaking hypothesis and the literature on which it depends do not meet the standards of evidence-based medicine.

Why admitted cases of AHT make a low quality reference standard: A survey of people accused of AHT in France

Several influential articles that attempt to establish diagnostic methods for Abusive Head Trauma (AHT) use admitted cases as a reference standard. This study analyses a survey of people accused of AHT in France, to understand the environment and situations in which such admissions are made. Multiple reasons to question the reliability of admissions to AHT are demonstrated in the responses, including reduced sentences, the return of children to the family home, a desire to stop accusations being leveled at a partner and for legal proceedings to end. These factors must be considered in the context of proceedings that are long, expensive and stressful, leading to depression and financial hardship, and that seem to be inevitably heading towards conviction. The ineluctable conclusion is that admitted cases do not make a suitably reliable reference standard for undertaking scientific investigation, or for validating the diagnostic methods used for AHT.

Exploring the Vitreoretinal Interface: a Key Instigator of Unique Retinal Hemorrhage Patterns in Pediatric Head Trauma

Purpose

Various types of trauma can cause retinal hemorrhages in children, including accidental and nonaccidental head trauma. We used animal eyes and a finite element model of the eye to examine stress patterns produced during purely linear and angular accelerations, along with stresses attained during simulated repetitive shaking of an infant.

Methods

Using sheep and primate eyes, sclerotomy windows were created by removing the sclera, choroid, and retinal pigment epithelium to expose the retina. A nanofiber square was glued to a 5 mm² area of retina. The square was pulled and separated from vitreous while force was measured. A finite element model of the pediatric eye was used to computationally measure tension stresses during shaking.

Results

In both sheep and primate eyes, tension stress required for separation of retina from vitreous range from 1 to 5 kPa. Tension stress generated at the vitreoretinal interface predicted by the computer simulation ranged from 3 to 16 kPa during a cycle of shaking. Linear acceleration generated lower tension stress than angular acceleration. Angular acceleration generated maximal tension stress along the retinal vasculature. Linear acceleration produced more diffuse force distribution centered at the poster pole.

Conclusions

The finite element model predicted that tension stress attained at the retina during forcible shaking of an eye can exceed the minimum threshold needed to produce vitreoretinal separation as measured in animal eyes. Furthermore, the results show that movements that involve significant angular acceleration produce strong stresses localized along the vasculature, whereas linear acceleration produces weaker, more diffuse stress centered towards the posterior pole of the eye.

Determining the Tractional Forces on Vitreoretinal Interface Using a Computer Simulation Model in Abusive Head Trauma

PURPOSE

Abusive head trauma (AHT) is the leading cause of infant death and long-term morbidity from injury. The ocular consequences of AHT are controversial, and the pathophysiology of retinal research findings is still not clearly understood. It has been postulated that vitreoretinal traction plays a major role in the retinal findings. A computer simulation model was developed to evaluate the vitreoretinal traction and determine whether the distribution of forces in different layers and locations of the retina can explain the patterns of retinal hemorrhage (RH) seen in AHT.

DESIGN

Computer simulation model study.

METHODS

A computer simulation model of the pediatric eye was developed to evaluate preretinal, intraretinal, and subretinal stresses during repetitive shaking. This model was also used to examine the forces applied to various segments along blood vessels.

RESULTS

Calculated stress values from the computer simulation ranged from 3-16 kPa at the vitreoretinal interface through a cycle of shaking. Maximal stress was observed at the periphery of the retina, corresponding to areas of multiple vessel bifurcations, followed by the posterior pole of the retina. Stress values were similar throughout all 3 layers of the retina (preretinal, intraretinal, and subretinal layers).

CONCLUSIONS

Ocular manifestations from AHT revealed unique retinal characteristics. The model predicted stress patterns consistent with the diffuse retinal hemorrhages (RH) typically found in the posterior pole and around the peripheral retina in AHT. This computer model demonstrated that similar stress forces were produced in different layers of the retina, consistent with the finding that retinal hemorrhages are often found in multiple layers of the retina. These data can help explain the RH patterns commonly found in AHT.

New grading criterion for retinal haemorrhages in term newborns based on deep convolutional neural networks

BACKGROUND

To define a new quantitative grading criterion for retinal haemorrhages in term newborns based on the segmentation results of a deep convolutional neural network.

METHODS

We constructed a dataset of 1543 retina images acquired from 847 term newborns, and developed a deep convolutional neural network to segment retinal haemorrhages, blood vessels and optic discs and locate the macular region. Based on the ratio of areas of retinal haemorrhage to optic disc, and the location of retinal haemorrhages relative to the macular region, we defined a new criterion to grade the degree of retinal haemorrhages in term newborns.

RESULTS

The F1 scores of the proposed network for segmenting retinal haemorrhages, blood vessels and optic discs were 0.84, 0.73 and 0.94, respectively. Compared with two commonly used retinal haemorrhage grading criteria, this new method is more accurate, objective and quantitative, with the relative location of the retinal haemorrhages to the macula as an important factor.

CONCLUSIONS

Based on a deep convolutional neural network, we can segment retinal haemorrhages, blood vessels and optic disc with high accuracy. The proposed grading criterion considers not only the area of the haemorrhages but also the locations relative to the macular region. It provides a more objective and comprehensive evaluation criterion. The developed deep convolutional neural network offers an end-to-end solution that can assist doctors to grade retinal haemorrhages in term newborns.

Ophthalmology referral as part of a multidisciplinary approach to suspected abusive head trauma

OBJECTIVE

To determine the use of ophthalmology consultation as part of investigation of children with suspected abusive head trauma (AHT).

METHODS

Retrospective chart review of children under age 3 years evaluated at McMaster Children's Hospital for suspected AHT from January 2011 to December 2017.

RESULTS

Fifty-seven children were investigated, and 29 (50.9%) of these were determined to have likely AHT. Eleven (19.3%) had other nonaccidental injuries. A mean of 3.6 consulting services were involved. Neuroimaging was performed for 52 patients (91.2%), including all patients in the AHT group. Intracranial hemorrhage (ICH) was present in 21 of the 29 AHT children (72.4%). All 57 patients had a dilated fundus examination, and retinal hemorrhages (RH) were seen in 23 patients (40.4%), including 16 (55.2%) in the AHT group. All patients with RH in AHT also had ICH. In the AHT group, there were more cases of hemorrhages too numerous to count (68.8% vs 28.6%), multilayered hemorrhages (75.0% vs 57.1%), and hemorrhages in the posterior pole and periphery (87.5% vs 42.9%) when compared with patients with RH from other etiologies. Retinoschisis was seen in the AHT group only in 3 patients (18.8%).

CONCLUSIONS

A multidisciplinary approach is important when investigating suspected AHT. Not every child with RH had suffered AHT; however, children with AHT showed more widespread and more multilayered RH. The only finding specific to AHT was retinoschisis.

Retinal Hemorrhages: Abusive Head Trauma or Not?

Abusive head trauma is an important cause of morbidity and mortality in infants and young children. Retinal hemorrhages (RHs) are frequently seen, particularly during dilated eye examination of these children. This review focuses on the evaluation of children with RH, with emphasis on the differential diagnosis, pathophysiology, and distinguishing features of RHs due to abusive head trauma. Many causes exist for RHs in infants and children. Most medical and accidental traumatic causes result in a pattern of RH that is nonspecific and not typical of the pattern and distribution of RHs seen in children with abusive head trauma. In children with intracranial hemorrhage and concerns for abuse, the finding of severe, multilayered RHs extending to the periphery of the retina is very specific for abuse as the cause of the findings, especially if retinoschisis is present. There are few other accidental traumatic mechanisms associated with retinoschisis, and the history of such a traumatic event is readily apparent. The indications for ophthalmologic consult, optimal timing of the eye examination, and significance of the findings are specifically discussed.

Ultra-Widefield Imaging for Pediatric Retinal Disease

This article explores the development of retinal imaging, with particular emphasis on ultra-widefield imaging and the key concept of field of view. Two ultra-widefield imaging platforms are examined in detail-Optomap and Spectralis-noncontact imaging systems that include protocols for performing angiography in infants. Applications of ultra-widefield imaging are illustrated using case studies, including diagnosis, monitoring, and screening.