A vitreous hemorrhage is a serious medical event where bleeding occurs into the vitreous humor, the clear, gel-like substance that fills the large central cavity of the eye. This sudden leakage of blood immediately clouds the normally transparent medium, which is designed to allow light to pass unobstructed to the retina. Because this condition often signals a deeper underlying issue, it requires immediate evaluation by an eye specialist to protect vision. The hemorrhage itself is typically painless, but the sudden onset of vision changes is a strong indicator.
Defining the Condition and Its Visual Impact
The vitreous humor is composed mostly of water, collagen, and hyaluronic acid, giving it a jelly-like consistency that helps the eyeball maintain its spherical shape. For clear vision, this gel must remain perfectly clear, allowing focused light from the lens to strike the light-sensitive retina lining the back of the eye. When blood vessels break and leak blood cells into this space, the light path is instantly obscured. The severity of the visual disruption is directly proportional to the amount of blood present.
Patients experience a range of symptoms, from mild visual obscuration to profound, sudden vision loss. Minor bleeds may appear as a sudden shower of fine black spots, known as floaters, or as cobweb-like strands moving across the field of view. As the hemorrhage becomes more substantial, vision can take on a hazy or cloudy quality, often described as seeing through a curtain or a veil. In the most severe cases, the entire field of vision may be lost, or the patient may perceive a red or dark tint due to the dense accumulation of blood. Symptoms are frequently worse in the morning because the blood cells settle toward the back of the eye overnight, maximizing the obstruction over the central visual axis.
Primary Underlying Causes
The source of the bleeding is almost always from the vascular structures of the retina or the surrounding tissues. The most frequent cause of spontaneous vitreous hemorrhage in adults is Proliferative Diabetic Retinopathy (PDR), an advanced stage of diabetic eye disease. In PDR, a lack of oxygen triggers the growth of fragile, abnormal new blood vessels, known as neovascularization, which grow on the surface of the retina and into the vitreous. These delicate vessels are easily ruptured by vitreous movement, leading to a hemorrhage.
The second major category of causes relates to mechanical forces, primarily involving the vitreous gel pulling on the retina. As the vitreous naturally shrinks and separates from the retina with age, posterior vitreous detachment (PVD) occurs. If the vitreous is strongly attached to a retinal blood vessel, the pulling motion can tear the vessel, causing a bleed. A more serious mechanical event occurs when the vitreous traction creates a retinal tear, which can rupture an adjacent blood vessel.
Trauma to the eye, such as a blunt impact, is the most common cause in younger individuals. Other underlying vascular conditions, such as retinal vein occlusions, can also lead to the formation of fragile new blood vessels that are prone to bleeding.
Diagnostic Procedures and Medical Evaluation
Diagnosing a vitreous hemorrhage is typically straightforward, but the challenge lies in determining the precise source of the bleeding and ruling out associated complications, especially a retinal detachment. The ophthalmologist begins with a thorough history and a slit-lamp examination, which can often detect red blood cells floating just behind the lens. The standard comprehensive examination also includes indirect ophthalmoscopy, where the doctor uses a bright light and a condensing lens to view the entire retina.
If the hemorrhage is dense and completely obscures the view of the retina, a specialized test known as B-scan ultrasonography becomes necessary. This procedure uses high-frequency sound waves to create a cross-sectional image of the eye’s internal structures. B-scan ultrasonography is instrumental because sound waves pass through the blood-filled vitreous, allowing the physician to identify or rule out a retinal tear or detachment. The findings from these diagnostic tests guide the immediate treatment plan, determining whether the patient can be safely observed or requires urgent surgical intervention.
Treatment Approaches
The treatment strategy is determined by the amount of blood present, the underlying cause, and whether a retinal detachment or tear is present. For minor hemorrhages, especially those where a retinal tear has been ruled out, the initial approach is observation, allowing the body time to naturally reabsorb the blood. The body’s immune cells, specifically macrophages, gradually break down and clear the red blood cells, a process that can take several weeks to months.
During this observation period, patients are advised to keep their head elevated, even while sleeping. This uses gravity to encourage the blood to settle to the bottom of the eye cavity, potentially clearing the central visual axis. However, if the blood fails to clear within one to three months, or if the vision loss is severe, surgical intervention is necessary. The definitive surgical procedure is a pars plana vitrectomy.
The vitrectomy involves the surgeon making tiny incisions in the sclera, the white outer wall of the eye, to access the vitreous cavity. Micro-instruments are used to carefully remove the blood-filled vitreous gel, which is then replaced with a clear saline solution or sometimes a gas or oil bubble, restoring transparency. Once the opaque vitreous is removed, the surgeon can directly visualize the retina to repair any tears, remove scar tissue, or perform laser photocoagulation to seal leaking vessels. This combined approach clears the blood to restore vision and treats the underlying pathology to prevent future bleeding episodes.