Rubeosis iridis is a

medical condition A disease is a particular abnormal condition that negatively affects the structure or function (biology), function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medica ...

of the iris of the

eye Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and conv ...

in which new abnormal

blood vessel Blood vessels are the structures of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide away from ...

s (formed by

neovascularization Neovascularization is the natural formation of new blood vessels ('' neo-'' + ''vascular'' + '' -ization''), usually in the form of functional microvascular networks, capable of perfusion by red blood cells, that form to serve as collateral circula ...

) are found on the surface of the iris.

Causes

This condition is often associated with

diabetes Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level (hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ...

in advanced proliferative

diabetic retinopathy Diabetic retinopathy (also known as diabetic eye disease), is a medical condition in which damage occurs to the retina due to diabetes mellitus. It is a leading cause of blindness in developed countries. Diabetic retinopathy affects up to 80 perc ...

. Other conditions causing rubeosis iridis include

central retinal vein occlusion Central retinal vein occlusion, also CRVO, is when the central retinal vein becomes occluded, usually through thrombosis. The central retinal vein is the venous equivalent of the central retinal artery and both may become occluded. Since the centra ...

, ocular ischemic syndrome, and chronic retinal detachment.

Pathophysiology

It is usually associated with disease processes in the

retina The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which then ...

, which involve the retina becoming starved of oxygen (

ischaemic Ischemia or ischaemia is a restriction in blood supply to any tissue, muscle group, or organ of the body, causing a shortage of oxygen that is needed for cellular metabolism (to keep tissue alive). Ischemia is generally caused by problems ...

). The ischemic retina releases a variety of factors, the most important of which is

vascular endothelial growth factor Vascular endothelial growth factor (VEGF, ), originally known as vascular permeability factor (VPF), is a signal protein produced by many cells that stimulates the formation of blood vessels. To be specific, VEGF is a sub-family of growth factors, ...

(VEGF). These factors stimulate the formation of new blood vessels ( angiogenesis). These new vessels do not have the same characteristics as the blood vessels originally formed in the eye. In addition, new blood vessels can form in areas that do not have them. Specifically, new blood vessels can be observed on the iris. In addition to the blood vessels in the iris, they can grow into the angle of the eye. These blood vessels eventually go through a process called

fibrosis Fibrosis, also known as fibrotic scarring, is a pathological wound healing in which connective tissue replaces normal parenchymal tissue to the extent that it goes unchecked, leading to considerable tissue remodelling and the formation of permane ...

which closes the normal physiologic anatomy of the angle. The closing of the angle prevents fluid from leaving the eye resulting in an increase in

intraocular pressure Intraocular pressure (IOP) is the fluid pressure inside the eye Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response fu ...

. This is called neovascular glaucoma.

Treatment

If caught early, the neovascularization can be reversed with prompt panretinal photocoagulation (PRP), or injection of anti-VEGF medications with subsequent PRP. The injection blocks the direct effect of VEGF and acts more quickly but will wear off in about six weeks.Davidorf FH, Mouser JG, Derick RJ. "Rapid improvement of rubeosis iridis from a single bevacizumab (Avastin) injection." ''Retina.'' 2006 Mar;26(3):354-6. . PRP has a slower onset of action but can last permanently. Once the neovascularization has been longstanding, the new vessels recruit fibrous tissue, and as this forms and contracts, the angle can be permanently damaged, and will not respond to treatment. If this occurs, then surgical intervention is required to reduce the pressure (such as a glaucoma drainage implant)

References

External links

{{Eye pathology Disorders of iris and ciliary body

Causes

Pathophysiology

Treatment

See also

References

External links