Vitreous Hemorrhage

Updated: May 04, 2015
  • Author: Brian A Phillpotts, MD, MD; Chief Editor: Hampton Roy, Sr, MD  more...
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Overview

Background

Vitreous hemorrhage is the extravasation of blood into one of the several potential spaces formed within and around the vitreous body. This condition may result directly from retinal tears or neovascularization of the retina, or it may be related to bleeding from preexisting blood vessels in these structures.

The vitreous body is bounded posterolaterally by the internal limiting membrane of the retina, anterolaterally by the nonpigmented epithelium of the ciliary body, and anteriorly by the lens zonular fibers and posterior lens capsule. The retrolental space of Erggelet and the canal of Petit are potential spaces. These 2 spaces are located between the anterior hyaloid membrane, the posterior lens capsule, and the orbiculoposterocapsular portion of the zonular fibers. The hyaloideocapsular ligament separates them from each other.

The Cloquet canal and the bursa premacularis are fluid-filled spaces within the formed vitreous into which blood can enter during vitreous hemorrhage. The aqueous-filled space anterior to the formed vitreous is called the canal of Hannover. This space is located between the orbiculoanterocapsular and posterocapsular portions of the zonular fibers.

Historically, anatomists do not consider it a part of vitreous humor; however, hemorrhage into this space is considered functionally as vitreous hemorrhage. The same is true for bleeding into the retrohyaloid or subhyaloid spaces and for sub–internal limiting membrane hemorrhage.

On April 20, 1970, the first pars plana vitrectomy for the treatment of nonclearing vitreous hemorrhage was performed by Machemer. [1] Prior to pars plana vitrectomy, the removal of nonclearing vitreous hemorrhage was attempted by excising vitreous gel through the pupillary aperture using cellulose sponges and scissors via a corneoscleral incision, which was coined "open-sky" vitrectomy by Kasner. [2] The procedure was frequently unsuccessful, and patients often had a permanent reduction in vision.

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Pathophysiology

The vitreous has 3 strong attachment areas with the retina. The strongest attachment straddles the most anterior area of the retina (ora serrata) where a 4-mm circular band forms the vitreous base. Traction at the vitreous base usually is transmitted to the adjacent peripheral retina. The next strong attachment of the vitreous is at the circular zone around the optic nerve head. This zone becomes progressively weakened with increasing age, and it becomes easily separated with posterior vitreous detachment.

In the adult, the vitreous body volume is approximately 4 mL, which is 80% of the globe. The content of the vitreous is 99% water, and the remaining 1% mostly is composed of collagen and hyaluronic acid. Additionally, there are a few other soluble components such as ions, proteins, and trace cells. These components account for the gelatinous but clear nature of the vitreous.

The vitreous is avascular and inelastic. Pathological mechanisms of vitreous hemorrhage can include hemorrhage from diseased retina, traumatic insult, and/or spread of hemorrhage into the retina and vitreous from any other intraocular sources.

Given the history and physical findings, it also may be reasonable to consider extraocular etiologies such as leukemia. Usually, coagulation disorders or anticoagulant therapy does not cause vitreous hemorrhage; however, bleeding from abnormal new vessels or rupture of normal retinal vessels from direct or indirect trauma frequently is associated with vitreous hemorrhage. Bleeding from neovascular and fragile vessels in proliferative diabetic retinopathy, proliferative sickle cell retinopathy, ischemic retinopathy secondary to retinal vein occlusion, and retinopathy of prematurity are among the most common pathological causes of vitreous hemorrhage.

The most common pathogenesis of bleeding in this group of disorders is believed to be retinal ischemia causing the release of angiogenic vasoactive factors, most notably vascular endothelial growth factor (VEGF), basic fibroblast growth factors (bFGF), and insulin-like growth factor (IGF). The second most frequent pathological mechanism for vitreous hemorrhage is tearing of the retinal vessels caused by either a break in the retina or detachment of the posterior vitreous, while the cortical vitreous is adherent to the retinal vessels. In addition, patients with sickle cell retinopathy may show a salmon-patch hemorrhage caused by blowout in the vessel wall following abrupt occlusion in the arterioles by aggregated sickled red blood cells.

Other less common pathological mechanisms of vitreous hemorrhage include subretinal bleeding with secondary extension into the vitreous cavity.

Age-related macular degeneration and choroidal melanoma are the two leading causes of vitreous hemorrhage secondary to breakthrough bleeding. Terson syndrome is subarachnoid hemorrhage associated with vitreous bleeding caused by rupture of retinal venules and/or capillaries as a result of a sudden increase in intracranial pressure (which is transmitted to the retinal vasculature via the optic nerve).

Reports have shown that about 33% of patients with subarachnoid hemorrhage may have associated intraocular hemorrhage, and approximately 6% of patients have vitreous hemorrhage. In Terson syndrome, branches of the central retinal vein or the central retinal vein itself is the most common source of intraocular bleeding. Terson syndrome occurs mostly in younger individuals (age 30-50 y).

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Epidemiology

Frequency

United States

The prevalence of vitreous hemorrhage tends to parallel the frequency of the causative disease. In general, the cause-prevalence of vitreous hemorrhage depends on the study population, mean age of the patients, and geographical region where the study is conducted. In adults, proliferative diabetic retinopathy is the most frequent cause of vitreous hemorrhage, 31.5-54% in the United States, 6% in London, and 19.1% in Sweden.

The other causes of vitreous hemorrhage include the following:

Rare causes of vitreous hemorrhage account for about 6.4-18% of vitreous hemorrhage. In several studies, 2-7.6% of the hemorrhage could not be attributed to a specific cause.

The leading cause of vitreous hemorrhage in young people is trauma.

Congenital retinoschisis and pars planitis also may cause vitreous hemorrhage in both children and adults.

Mortality/Morbidity

The complications of vitreous hemorrhage include hemosiderosis bulbi with photoreceptor toxicity, glaucoma, severe floaters, and myopic shift in infants.

In hemosiderosis bulbi, iron (Fe3+) is released during hemoglobin breakdown. This occurs intracellularly in macrophages with subsequent storage as ferritin or hemosiderin. Alternatively, the catabolism of hemoglobin can take place extracellularly and the released iron binds to vitreous proteins with iron-binding capacity, such as lactoferrin and transferrin. The vitreous contains 13 times more iron-binding proteins relative to the serum, with a physiological saturation of the total iron-binding capacity of about 35%. Given the slow clearance of blood in the vitreous, the persistence of intact red blood cells and the slow hemolysis in the vitreous, the amount of iron released from hemoglobin is a relatively small fraction of that available at any given time.

The exact mechanism of post–vitreous hemorrhage retinal damage has not been completely elucidated. It currently is believed that this damage may be caused by direct or indirect toxicity of iron. For example, iron enters cell wall membranes via secondary lysosomes with the liberation of contained enzymes causing indirect damage. Iron also has been implicated in the release of mitogenic growth factor from macrophages following phagocytosis of blood from vitreous hemorrhage.

Overall, patients with long-standing vitreous hemorrhage and relatively normal retina tend to have good visual acuity. The vitreous hemorrhage-induced glaucoma is secondary to the blockade of the trabecular meshwork by formed ghost cells due to long-standing blood cells in the vitreous. Ghost cells are small, khaki-colored, spherical, more rigid cells, which develop from long-standing red blood cells in the vitreous where there is a relatively low oxygen tension. In hemolytic glaucoma, the trabecular meshwork is blocked by red blood cell debris, free hemoglobin, and hemoglobin-laden macrophages. In hemosiderotic glaucoma, the iron derived from vitreous hemorrhage binds to the trabecular meshwork mucopolysaccharide causing endothelial cell damage with possible complications of sclerosis and obliteration of the intertrabecular spaces. This form of glaucoma often presents after years of recurrent vitreous hemorrhage.

Myopic shift and amblyopia have been reported to follow long-standing vitreous hemorrhage in infants, especially in those younger than 2 years.

In high myopic persons, the risk of retinal tears, detachment, and associated vitreous hemorrhage is increased.

In general, iron-related toxicity may become clinically apparent in instances of significant long-standing vitreous hemorrhage, often with histopathologic signs of hemosiderosis.

Race

The demographics of vitreous hemorrhage correspond to the incidence of the underlying disease with which it is associated.

In blacks, diabetes and sickle cell disease tend to be the most common.

In elderly whites with vitreous hemorrhage, retinal vascular tears and neovascularization caused by proliferative diabetic retinopathy and branch retinal vein occlusion are more common. In the same population, macular degeneration and breakthrough bleeding into the vitreous are not infrequent.

Sex

Corresponds to the incidence of the underlying disease with which it is associated

Age

Corresponds to the incidence of the underlying disease with which it is associated

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