Vitreous hemorrhage is blood within the vitreous space, the main cavity inside the eye.

The only symptoms of vitreous hemorrhage are visual symptoms. The vitreous cavity has no nerves and, therefore, cannot sense pain, pressure, etc. The visual symptoms experienced by patients with vitreous hemorrhage vary from mild to severe, depending on the hemorrhage. A small amount of hemorrhage in the vitreous might be appreciated as floating black dots (like pepper grains), a red or dark strand, or a cloud floating or stationary within the field of vision. A more severe hemorrhage might produce symptoms such as a large dark curtain blocking part of the vision or even the whole vision. It is possible to have 20/20 vision with a small vitreous hemorrhage. A large vitreous hemorrhage might reduce the vision down to the “hand movements” or “light perception” level (inability to see well enough to count fingers or see across the room). Symptoms will only affect the eye with bleeding – with both eyes open, a person might not be aware of the visual loss.

There are many causes of vitreous hemorrhage. The blood almost always originates from the blood vessels of the retina – the thin tissue which lines the back wall of the vitreous cavity. Bleeding can occur as a complication of the vitreous gel peeling free from the retina – a process called posterior vitreous detachment (see flashes and floaters). As the vitreous peels free, it can tug on a retinal blood vessel hard enough to make it leak. The retina can also bleed into the vitreous cavity if there is a retinal tear, a condition which develops from the vitreous gel pulling on the retina hard enough to rip it. Sometimes, bleeding originates from abnormal new blood vessels growing on the retina (because of poor circulation). This occurs as a complication of diabetic retinopathy and other disorders that reduce the circulation in the retina. Less common causes of vitreous hemorrhage include bleeding from an aneurysm on a retinal blood vessel, or bleeding from macular degeneration.

The prognosis varies depending on the cause of the hemorrhage. Most vitreous hemorrhages will eventually clear as the blood gradually sinks to the bottom of the eyeball. The center of the vision clears as the blood sinks, but this is a process that can take weeks or months. An operation called vitrectomy can be considered in cases of non-clearing vitreous hemorrhage. The factor which determines the long-term visual prognosis is the cause of the hemorrhage. For example, if hemorrhage results from the vitreous gel pulling on a retinal blood vessel (without a retinal tear or retinal detachment), then the visual prognosis is excellent. If advanced diabetic retinopathy bleeds into the vitreous cavity, the prognosis is related to the severity of the diabetic eye disease. An urgent eye exam should be performed when vitreous hemorrhage is suspected. It should be assumed that a serious eye disorder is present until proven otherwise.

A thorough eye exam by an eye doctor is the best way to diagnose vitreous hemorrhage. Dilation of the pupils will be necessary to properly evaluate the eye for the cause of the hemorrhage. If the hemorrhage is severe, your eye doctor may need to examine the eye with ultrasonography – a test that uses sound waves to “visualize” the eye structures hidden behind the hemorrhage. Angiography of the retina may be done to assess the cause of the hemorrhage.

Treatment really involves two issues – one is treating the hemorrhage and the other is treatment for the cause of the hemorrhage. Most vitreous hemorrhages will clear spontaneously in weeks or months. It is advisable to elevate the head (like in a sitting position) to help promote settling of the hemorrhage within the eye cavity. Patients with vitreous hemorrhage should avoid laying down flat in bed, and if possible, should sleep in a reclining chair or with several pillows under their head in bed. Vitrectomy surgery can be considered for non-clearing vitreous hemorrhage. The cause of the hemorrhage might also need treatment. Underlying conditions (such as retinal tear, retinal detachment, diabetic retinopathy, and aneurysm) may need treatment more urgently than the vitreous hemorrhage they cause.