For years, certain classic retinal indicators have been considered absolute evidence of shaken baby syndrome. Doctors have made explicit statements that other activities like falls can't cause similar injuries (with a typical "well given infinite time" hedge). other source
Is it proven that the severe retinal haemorrhages can only be attributed to SBS?
There is no disagreement among the mainstream medical community about the injury caused by Shaken Baby syndrome/Abusive head trauma which includes severe bleeding on the back surface of the eyes (retinal hemorrhages) identified by the current best evidence-based literature that reliably distinguish abusive injury from accidental injury. Retinal hemorrhages are known to be highly suspicious for abuse resulting from Shaken Baby syndrome/Abusive head trauma.
Published accounts of confessions document that some parents have shaken their children on repeated occasions, leading to the injuries that physicians identify in these cases. These reports confirm the published clinical findings.
The American Academy of Pediatrics, American Academy of Ophthalmology, American Association for Pediatric Ophthalmology and Strabismus, American Academy of Family Physicians, American College of Surgeons, American Association of Neurological Surgeons, Pediatric Orthopaedic Society of North America, American College of Emergency Physicians, Canadian Paediatric Society, Royal College of Paediatrics and Child Health, Royal College of Radiologists, and American Academy of Neurology all recognize SBS/AHT as a form of infant abuse and have published position statements which describe their disciplines’ roles in its diagnosis and prevention. Both the Centers for Disease Control and Prevention of the U.S. Department of Health and Human Resources and the World Health Organization have similarly published position statements in support of the diagnosis of SBS/AHT.
Numerous studies have documented the highly significant correlation of extensive, multilayered retinal hemorrhages with abusive head trauma, yet the exact mechanism of injury eludes us. Recent research creating finite element modeling of the infant eye confirms that rhythmic shaking significantly increases the stress on the retina. Further, the areas of greatest stress are found at the posterior pole and the peripheral retina, precisely where retinal hemorrhages are typically documented in cases of abusive head trauma.
The clinical features of Shaken Baby syndrome in Japan are also found to be comparable to those detailed in the Western medical literature for retinal haemorrhages through research which is found here and here.
An evidence-based review in 2008 found that 53-80% incidence of retinal haemorrhages with abusive head injury and a 0-10% incidence with proven severe accidental trauma.
Studies found a 53-80% incidence of RH with abusive head injury and a 0-10% incidence with proven severe accidental trauma. RHs are found bilaterally 62.5-100% of the time in SBS cases, and flame-shaped hemorrhages are the most common. The incidence of RH from convulsions, chest compressions, forceful vomiting, and severe persistent coughing in the absence of another condition known to cause RH is 0.7%, 0-2.3%, 0%, and 0%, respectively.
Our systematic review confirms that although certain patterns of RH were far commoner in AHT, namely large numbers of RH in both the eyes, present in all layers of the retina, and extension into the periphery, there was no retinal sign that was unique to abusive injury. RH are rare in accidental trauma and, when present, are predominantly unilateral, few in number and in the posterior pole.
Research involving surviving/deceased victims, models of animals, mechanical dummies, and finite element analysis have demonstrated a pattern of vitreoretinal traction in the retinal hemorrhages suffered in SBS.
A systematic meta-analytic review on the clinical and radiographic characteristics associated with abusive and nonabusive head trauma in 2012 found that retinal hemorrhages were significantly associated with abusive head trauma in children.
In examining only studies deemed to be high quality, we found that subdural hemorrhage(s), cerebral ischemia, retinal hemorrhage(s), skull fracture(s) plus intracranial injury, metaphyseal fracture(s), long bone fracture(s), rib fracture(s), seizure(s), apnea, and no adequate history given were significantly associated with AHT.
Researchers however agree that there is difficulty in developing models that causes force replication required to cause retinal hemorrhage in children.
Retinal hemorrhage is a cardinal manifestation of abusive head trauma. Over the 30 years since the recognition of this association, multiple streams of research, including clinical, postmortem, animal, mechanical, and finite element studies, have created a robust understanding of the clinical features, diagnostic importance, differential diagnosis, and pathophysiology of this finding. The importance of describing the hemorrhages adequately is paramount in ensuring accurate and complete differential diagnosis. Challenges remain in developing models that adequately replicate the forces required to cause retinal hemorrhage in children. Although questions, such as the effect of increased intracranial pressure, hypoxia, and impact, are still raised (particularly in court), clinicians can confidently rely on a large and solid evidence base when assessing the implications of retinal hemorrhage in children with concern of possible child abuse.
