Funduscopic Findings in Subarachnoid Hemorrhage with Hydrocephalus
The most likely funduscopic finding in this patient with subarachnoid hemorrhage (SAH) and acute hydrocephalus is intraocular hemorrhage, specifically subhyaloid or vitreous hemorrhage (Terson syndrome).
Clinical Context
This 28-year-old patient presents with classic SAH features—sudden severe headache, neck stiffness, vomiting, and depressed consciousness—with CT confirmation showing blood in cisternal spaces, third ventricle, and lateral ventricles with associated hydrocephalus 1. The presence of intraventricular hemorrhage and hydrocephalus are significant findings that correlate with specific ocular manifestations 2.
Funduscopic Findings in SAH
Intraocular Hemorrhage (Terson Syndrome)
- Intraocular hemorrhage occurs in approximately 10-40% of patients with aneurysmal SAH, manifesting as subhyaloid, intraretinal, or vitreous hemorrhage 1
- The mechanism involves sudden elevation of intracranial pressure at the moment of aneurysm rupture, which transmits through the optic nerve sheath, causing rupture of retinal vessels 3
- This finding is particularly associated with severe SAH grades and the presence of intraventricular hemorrhage, both of which are present in this patient 2
Why Not the Other Options?
Cotton wool spots are characteristic of hypertensive retinopathy, diabetic retinopathy, or vasculitis—not acute SAH 4. While this patient has risk factors (smoking, amphetamine use) for hypertension, cotton wool spots represent chronic microvascular ischemia rather than acute hemorrhagic events.
Increased optic cup-to-disc ratio indicates chronic glaucomatous damage developing over months to years, which is irrelevant to acute SAH presentation 4.
Pale optic disc suggests chronic optic atrophy from longstanding compression or ischemia, not an acute finding in SAH 4.
Papilledema Consideration
While acute hydrocephalus can theoretically cause elevated intracranial pressure and papilledema, papilledema typically requires sustained elevated ICP over days to weeks to develop visible disc swelling 4. In the acute setting described (patient just arriving to the emergency department), papilledema would not yet be apparent even if ICP is elevated 1.
Acute hydrocephalus occurs in 20-30% of SAH patients within 72 hours, and while it can cause elevated ICP requiring ventricular drainage, the funduscopic changes of papilledema lag behind the acute pressure elevation 1, 2.
Clinical Implications
- The presence of intraocular hemorrhage in SAH correlates with poor clinical grade and worse outcomes 1, 3
- This patient's acute hydrocephalus (evidenced by ventricular enlargement on CT) requires urgent external ventricular drainage, which can be performed safely without increasing rebleeding risk 2
- Approximately 40-80% of patients with diminished consciousness from acute hydrocephalus show improvement after CSF diversion 1
Management Priority
Immediate neurosurgical consultation for external ventricular drain placement is indicated given the depressed consciousness and radiographic hydrocephalus 1, 2. The funduscopic finding of intraocular hemorrhage, while diagnostically significant, does not alter acute management priorities focused on securing the aneurysm and managing elevated ICP 1, 3.