Subhyaloid hemorrhage appears as extravasated blood beneath the retinal layer. These are often described as “boat-shaped” hemorrhages to distinguish them from the “flame-shaped” hemorrhages on the superficial nerve fiber layer of the retina. They may occur as a result of blunt trauma but are perhaps best known as a marker for SAH. In SAH, the hemorrhages appear as a “puff” of blood emanating from the central disk.
Subhyaloid Hemorrhage. Subhyaloid hemorrhage seen on funduscopic examination in a patient with subarachnoid hemorrhage. (From Edlow JA, Caplan LR. Primary care: avoiding pitfalls in the diagnosis of subarachnoid hemorrhage. N Engl J Med. 2000;342:29-36. Reproduced with permission from John J. Weiter, MD, PhD.)
SAH, shaken impact syndrome, hypertensive retinopathy, and retinal hemorrhage should all be considered and aggressively evaluated.
Management and Disposition
No specific treatment is required for subhyaloid hemorrhage. Treatment is dependent on the underlying etiology. Appropriate specialty referral should be made in all cases.
A funduscopic examination looking for subhyaloid hemorrhage should be included in all patients with severe headache, unresponsive pediatric patients, or those with altered mental status.
The appearance of a retinal hemorrhage indicates its anatomic location. A subhyaloid hemorrhage lies over the retinal vessels—thus, they cannot be seen on funduscopic examination. In a subretinal hemorrhage (see Fig. 3.4), the vessels lie superficial to the hemorrhage and thus are easily seen.
Retinal Hemorrhages—Anatomic Location.