Traumatic hyphema, or blood in the anterior chamber, is a common complication of blunt or penetrating injury to the eye and can result in permanent vision loss. The goals of initial assessment include recognition and characterization of the hyphema and identification of associated orbital and ocular injuries. If ruptured globe is suspected, then emergent consultation with an ophthalmologist is critical to ensure preservation of vision. In addition, optimal outcome following a hyphema depends on early ophthalmologic intervention focused on prevention of rebleeding and avoidance of intraocular hypertension. In most instances, patients recover with vision intact. Vision loss is more likely in patients with large hyphemas, sickle hemoglobinopathy, or bleeding tendency.
This review covers the definition, epidemiology and pathophysiology of traumatic hyphema. Diagnosis and treatment are covered elsewhere. (See "Traumatic hyphema: Clinical features and management".)
- Hyphema refers to grossly visible blood in the anterior chamber of the eye (picture 1).
- Microhyphema describes dispersed red blood cells in the anterior chamber that do not layer out to form a gross fluid level (figure 1).
Incidence — The annual incidence of traumatic hyphema has been estimated at 12 injuries per 100,000 population, with males being affected three to five times more frequently than females [1-4]. Up to 70 percent of traumatic hyphemas occur in children, with a peak incidence between 10 and 20 years of age [1,3,4].
Required use of appropriate ocular protection can significantly decrease the incidence of traumatic eye injury during recreational sports in children [5,6].