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Vitreous Hemorrhage: Diagnosis and Treatment
Vitreous hemorrhage has an incidence of seven cases per 100,000, which makes it one of the most
common causes of acutely or subacutely decreased vision. Although the diagnosis of vitreous
hemorrhage is generally straightforward, management is dictated by uncovering the underlying
etiology.
Vitreous Anatomy
The vitreous humor is 99 percent water. The remaining 1 percent is made up of collagen and hyaluronic
acid, giving it a gelatinous consistency and optical clarity. The vitreous body is defined by the internal
limiting membrane of the retina posterolaterally, by the nonpigmented epithelium of the ciliary body
anterolaterally, and by the posterior lens capsule and lens zonular fibers anteriorly. This space represents
80 percent of the eye and has a volume of approximately 4 ml. The vitreous is firmly attached to the retina
in three places: the strongest attachment is anteriorly at the vitreous base, followed by the optic nerve
head and retinal vasculature.
Mechanisms of Hemorrhage
The mechanisms of vitreous hemorrhage fall into three main categories: abnormal vessels that are
prone to bleeding, normal vessels that rupture under stress, or extension of blood from an adjacent
source. (See “Mechanisms of Vitreous Hemorrhage.”)
Abnormal vessels. Abnormal retinal blood vessels are typically the result of neovascularization due
to ischemia in diseases such as diabetic retinopathy, sickle cell retinopathy, retinal vein occlusion,
retinopathy of prematurity or ocular ischemic syndrome. As the retina experiences inadequate oxygen
supply, vascular endothelial growth factor (VEGF) and other chemotactic factors induce neovascula-
rization. These newly formed vessels lack endothelial tight junctions, which predispose them to
spontaneous bleeding. They also coexist with a fibrous component that often contracts, putting
additional stress on already fragile vessels. Also, normal vitreous traction with eye movement can
lead to rupture of these vessels.
Rupture of normal vessels. Normal vessels can rupture when sufficient mechanical force overcomes
the structural integrity of the vessel. During a posterior vitreous detachment, vitreous traction on the
retinal vasculature may compromise a blood vessel, especially at the firm attachments mentioned
above. This may happen with or without a retinal tear or detachment. However, vitreous hemorrhage
in the setting of an acute symptomatic posterior vitreous detachment should alert the clinician that
the risk of a concurrent retinal break is quite high (70–95 percent).
Blunt or perforating trauma can injure intact vessels directly and is the leading cause of vitreous
hemorrhage in people younger than 40.
A rare cause of vitreous hemorrhage is Terson’s syndrome, which refers to an extravasation of
blood into the vitreous due to a subarachnoid hemorrhage. The blood is not an extension of the
subarachnoid hemorrhage. Rather the sudden increase in intracranial pressure can cause retinal
venules to rupture.
Blood from an adjacent source. Pathology adjacent to the vitreous can also cause vitreous
hemorrhage. Hemorrhage from retinal macroaneurysms, tumors and choroidal neovascularization
can all extend through the internal limiting membrane into the vitreous.
Signs and Symptoms
The symptoms of vitreous hemorrhage are varied but usually include painless unilateral floaters
and/or visual loss. Early or mild hemorrhage may be described as floaters, cobwebs, haze, shadows
or a red hue. More significant hemorrhage limits visual acuity and visual fields or can cause scotomas.
Patients often say vision is worse in the morning as blood has settled to the back of the eye, covering
the macula. Patients should be questioned regarding a history of trauma, ocular surgery, diabetes,
sickle cell anemia, leukemia, carotid artery disease and high myopia.
Complete examination consists of indirect ophthalmoscopy with scleral depression, gonioscopy to
evaluate neovascularization of the angle, IOP and B-scan ultrasonography if complete view of the
posterior pole is obscured by blood. Dilated examination of the contralateral eye can help provide clues
to the etiology of the vitreous hemorrhage, such as proliferative diabetic retinopathy.
The presence of vitreous hemorrhage is not hard to detect. At the slit lamp, red blood cells may be seen
just posterior to the lens with the slit beam set “off-axis” and the microscope on the highest power. In
nondispersed hemorrhage, a view to the retina may be possible and the location and source of the
vitreous hemorrhage may be determined. Vitreous hemorrhage present in the subhyaloid space is also
known as preretinal hemorrhage. Such a hemorrhage is often boat-shaped as it is trapped in the potential
space between the posterior hyaloid and the internal limiting membrane, and settles out like a hyphema.
Dispersed vitreous hemorrhage into the body of vitreous has no defined border and can range from a few
small distinct red blood cells to total obscuration of the posterior pole.
Natural History
The blood is typically cleared from within the vitreous hemorrhage at a rate of approximately 1 percent
per day. Blood outside the formed vitreous resolves more quickly. Vitreous hemorrhage is cleared more
quickly in syneretic and vitrectomized eyes, and more slowly in younger eyes with well-formed vitreous.
The natural history of vitreous hemorrhage depends on the underlying etiology with the worst
prognoses for diabetics and AMD patients.
With the exception of proliferative vitreoretinopathy, complications of vitreous hemorrhage typically
occur if blood has been present for more than one year.
Hemosiderosis bulbi is a serious complication thought to be caused by iron toxicity as hemoglobin is
broken down. Since hemolysis occurs slowly, the iron-binding capacity of proteins in the vitreous usually
outpaces the slow rate of hemolysis, thereby avoiding hemosiderosis bulbi.
Proliferative vitreoretinopathy. After vitreous hemorrhage, proliferative vitreoretinopathy can occur.
It is thought that macrophages and chemotactic factors induce fibrovascular proliferation, which can lead
to scarring and subsequent retinal detachment.
Ghost cell glaucoma. Ghost cells are spherical, rigid, khaki-colored red blood cells filled with denatured
hemoglobin present in long-standing vitreous hemorrhage. If these cells gain access to the anterior
chamber, their shape and rigidity can block the trabecular meshwork, resulting in ghost cell glaucoma.
Hemolytic glaucoma. In hemolytic glaucoma, free hemoglobin, hemoglobin-laden macrophages and
red-blood cell debris can block the trabecular meshwork.
Treatment
The presence of a retinal detachment may be determined using ultrasonography if an adequate view
of the posterior segment is not possible. Vitrectomy is performed urgently when a retinal detachment
or break is identified. Provided the retina is attached, observation is on an outpatient basis. If the view
to the posterior pole is blocked, limitation of activities and elevation of the head of the bed while sleeping
may allow the blood to settle inferiorly and permit visualization of the superior retina where retinal breaks
most commonly occur. Retinal breaks are sealed with cryotherapy or laser photocoagulation. If a retinal
detachment has been ruled out, patients may return to normal activities.
Once the retina can be visualized, treatment is aimed at the underlying etiology as soon as possible.
If neovascularization from proliferative retinopathy is the cause, laser panretinal photocoagulation is
performed, if possible through the residual hemorrhage, to cause regression of neovascularization.
A krypton laser may aid photocoagulation as it passes through hemorrhage better than argon lasers.
An indirect laser system may also allow energy delivery to the retina around a vitreous hemorrhage.
Alternatively, in the interim, intravitreal anti-VEGF agents may induce regression of the neovascularization
until laser photocoagulation is possible. Vitrectomy is also indicated for nonclearing vitreous hemorrhage,
neovascularization of the iris and/or angle, or ghost cell glaucoma. Timing of vitrectomy depends on the
underlying etiology. New therapies, such as intravitreal injection of hyaluronidase, are currently being
studied and may provide additional treatment options in the future.