Alex V. Levin, M.D. MHSc, FAAP, FAAO, FRCSC
Departments of Paediatrics and Ophthalmology and Vision Sciences
The Hospital for Sick Children
University of Toronto
Chair, International Advisory Board
National Center on Shaken Baby Syndrome
May 25, 2006
Retinal hemorrhages are a cardinal manifestation of Shaken Baby Syndrome (SBS). Examination by ophthalmologists familiar with ocular findings in SBS, is an essential part of evaluating suspected child victims and in situations of unexplained life-threatening events or sudden death.
Examination should be carried out with pupil dilation, either using eye drops, or through the naturally dilated pupils of the severely ill child. Ophthalmologists use the indirect ophthalmoscope to view the entire retina. Examination by non-ophthalmologists using only a direct ophthalmoscope is insufficient. After death, eyeball removal along with all orbital contents, is important to help to establish cause. Post mortem protocols have been published.*
In considering causation of retinal hemorrhage, it is important to detail types of retinal hemorrhage (preretinal, intraretinal, subretinal), number of hemorrhages, distribution of hemorrhages (confined to back [posterior pole] of the retina or spreading to edges [ora] of retina) and pattern of hemorrhages. Two-thirds of SBS victims have too numerous to count, multi-layered retinal hemorrhages extending to the ora. 15% have no retinal hemorrhages. Absence of retinal hemorrhage does not rule out child abuse. Traumatic retinoschisis is a particularly diagnostic lesion caused by traction applied to the retina by the vitreous jelly (which fills the eye and is attached firmly to the retina) as the child is submitted to repetitive acceleration-deceleration forces. The retina splits, creating a blood filled cystic cavity, not reported in otherwise well children except SBS victims and perhaps severe head crush injury which would otherwise be obvious by history.
Multiple other causes of retinal hemorrhage are usually easy to diagnose by history, other medical findings, and laboratory/radiologic evaluations.
Most other causes, including accidental short falls and cardiopulmonary resuscitation, perhaps except birth and leukemia, present only rarely with few retinal hemorrhages confined to the posterior pole. Although blood clotting disorders should be ruled out, these entities rarely result in severe hemorrhagic retinopathy. Routine childhood vaccinations and seizures do not cause retinal hemorrhage.
Although increased intracranial pressure, hypoxia, increased intrathoracic pressure (from the perpetrator’s hands squeezing the rib cage), and anemia may play small roles in developing retinal hemorrhages, the key factor is the unique repeated acceleration-deceleration forces that characterize SBS. This results in vitreo-retinal traction and perhaps damage to blood vessels and nerves behind the eye (orbit).
SBS survivors may have long term visual compromise. The main cause is brain injury to the vision centers (occipital lobes) and direct optic nerve injury.
* Gilliland MG, Levin AV, Enzenauer RW, Smith C, Parsons MA, Rorke-Adams LB, Lauridson JR, La Roche GR, Christmann LM, Mian M, Jentzen J, Simons K, Morad Y, Alexander R, Jenny C, Wygnanski-Jaffe T: Guidelines for postmortem protocol for ocular investigation of sudden unexplained infant death and suspected physical child abuse. Am J Forensic Med Pathol [in press]