Abusive Head Trauma
Abusive head trauma (AHT) or nonaccidental trauma, previously referred to as shaken baby syndrome, is physical abuse that results in traumatic brain injury as well as injury to other structures in the head and neck in a young child. Victims are usually younger than 5 years and are most commonly younger than 24 months. Though not necessarily a degenerative process, AHT induces a variety of changes over time and therefore is included in this section.
In a young child, ocular findings in AHT often result from repetitive acceleration-deceleration forces applied to the head with or without direct head trauma. Injuries stem from the complex interactions of ocular and intracranial forces, as well as injuries to other parts of the body. In cases of suspected AHT, the ophthalmologist may provide critical clinical evidence by performing a thorough dilated fundus examination. On clinical examination, the most frequent ocular finding is retinal hemorrhage, present in up to 90% of cases. However, the absence of retinal hemorrhages does not entirely exclude a diagnosis of AHT. Circumferential perimacular folds are considered a specific finding of AHT, but they are not pathognomonic.
Because AHT is sometimes fatal, forensic examination of the eyes at autopsy is important. On gross examination of the globe, retinal hemorrhages may be dispersed throughout the fundus (Fig 11-29A). Subdural hemorrhage in the optic nerve sheath is also present (Fig 11-29B) and can be appreciated as a bluish discoloration of the optic nerve sheath.
Histologic findings in the eye may include
hemorrhages involving any layer of the retina
hemorrhagic retinal schisis cavities, usually between the ILM and the rest of the neurosensory retina
retinal hemorrhages extending to the ora serrata
subdural hemorrhage in the optic nerve
subarachnoid, focal intradural and/or focal epidural hemorrhage of the optic nerve sheath
perimacular circumferential retinal fold, often surrounding hemorrhagic macular retinoschisis cavity
intrascleral hemorrhage adjacent to the optic nerve
As noted previously, no clinical or histopathologic findings are pathognomonic for AHT. Each case needs to be interpreted in the context of the clinical history and other clinical and pathologic findings. Whenever AHT is suspected, a physician is required by law in all US states and Canadian provinces to report the incident to a designated government agency. See BCSC Section 6, Pediatric Ophthalmology and Strabismus, for additional information on this topic.
Figure 11-29 Abusive head trauma. A, Gross examination of the globe reveals multiple retinal hemorrhages (arrowheads), including sub–internal limiting membrane hemorrhage (arrow) as a result of abusive head trauma. B, Cross section of the optic nerve reveals 360° of subdural hemorrhage (arrow).
(Courtesy of Nasreen A. Syed, MD.)
Excerpted from BCSC 2020-2021 series: Section 4 - Ophthalmic Pathology and Intraocular Tumors. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.