Shaken baby syndrome (SBS) is a constellation of findings (including serious brain injury manifest as bleeding and swelling) and retinal hemorrhages that occur when a baby is shaken repeatedly or the head impacts a hard object. It may also be called abusive head trauma (AHT). Many cases occur when a frustrated caretaker shakes a crying baby in an effort to quiet the baby. Baby heads are disproportionately large and the blood vessels are fragile, which makes the brain and eyes more susceptible to bleeding from non-accidental trauma [See figure 1]. The injuries can lead to permanent eye and/or brain damage.
The eyes are examined in suspected cases of SBS for bleeding (retinal hemorrhages) in the retina. Hemorrhages may occur above (pre-retina), within (intra-retina), or underneath (sub-retina) the retina. The layers of the retina may also be split in half (retinoschisis).
Dilating eye drops are administered to enlarge the pupil and facilitate the view of the retina. The retina is visualized using an instrument called an ophthalmoscope and special lenses by trained examiners. Fundus photographs are sometimes also obtained.
An eye examination is part of a systemic evaluation of a baby suspected of having SBS. The evaluation usually includes brain imaging (MRI or CT scan), bone x-rays (looking for fractures) and a social evaluation to asses for abuse risk. In addition, blood tests may be performed to check for other conditions such as bleeding disorders.
Retinal hemorrhages often resolve spontaneously, but amblyopia can develop quickly in an infant when vision is blocked by the hemorrhage. If the blood does not clear within weeks to months, eye surgery to remove the blood before amblyopia develops may be indicated. Permanent damage to vision can also occur as a result of direct eye and/or brain injury. Scarring of the retina and/or atrophy of the optic nerve may not become evident until months after the injury. In addition, brain injury may result in developmental delay, seizure, paralysis, and even death.
Revised November, 2012
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