Point-of-care handheld ophthalmic ultrasound in the diagnosis and evaluation of raised intracranial pressure and Terson syndrome: a description of two cases

Background Ultrasound (US) examination of the eye can be used to detect and monitor elevated intracranial pressure (ICP) and its consequences. Elevated ICP is transmitted to the contiguous optic nerve and its sheath (dura mater), thus underlying the development of papilledema and a widened sheath diameter. The US measurement of the optic nerve sheath diameter (ONSD) has previously been validated to diagnose and monitor raised ICP. The occurrence of vitreous hemorrhage in association with subarachnoid hemorrhage (SAH)—i.e., Terson syndrome—can also be easily diagnosed using ophthalmic US. Because of its relevance in anesthesia and critical care, we describe how to perform the technique illustrated by two cases. Case presentations A 72-yr-old man with hydrocephalus secondary to a SAH developed raised ICP following the removal of an external ventricular drainage (EVD) system. Daily ONSD measurements using handheld US allowed us to diagnose and monitor the progression and resolution of the intracranial hypertension following the placement of a second EVD system. We also describe the steps used to obtain ONSD measurements during the ophthalmic US examination of a 53-yr-old woman who presented with a stage IV SAH with concomitant bilateral vitreous hemorrhages or Terson syndrome. Conclusion Ophthalmic US using a handheld device to measure and monitor ONSD at the bedside is useful in diagnosing and monitoring the progression of intracranial hypertension following EVD removal in a patient with hydrocephalus secondary to SAH. Ophthalmic US can also be used to identify concomitant vitreous hemorrhage that is associated with a worse prognosis.