Rubeosis is an eye condition characterized by the abnormal growth of new, delicate blood vessels. This proliferation of fragile vessels can occur in various parts of the eye and often leads to severe complications.
Understanding Rubeosis
Rubeosis involves the development of delicate blood vessels in areas of the eye where they are not normally found. These new vessels often appear on the surface of the iris, the colored part of the eye, a condition specifically known as rubeosis iridis. They can also extend into the angle of the anterior chamber, which is the drainage area of the eye. These newly formed vessels are structurally weak and prone to bleeding.
Underlying Causes
The primary cause of rubeosis is ischemia, a lack of oxygen in the retina. When retinal tissue lacks blood supply, it releases growth factors, such as vascular endothelial growth factor (VEGF). These factors stimulate the formation of new, abnormal blood vessels.
Diabetic retinopathy, particularly its advanced form known as proliferative diabetic retinopathy, is the most common condition leading to rubeosis. Uncontrolled diabetes damages the small blood vessels in the retina, causing widespread ischemia and the subsequent release of VEGF. Other causes of ocular ischemia that can trigger rubeosis include central retinal vein occlusion, a blockage in the main venous drainage from the retina, and ocular ischemic syndrome, which often results from severe narrowing of the carotid artery in the neck.
Impact on Vision
Rubeosis can severely impact vision. A major complication is neovascular glaucoma, a severe form of secondary glaucoma where abnormal vessels block the eye’s natural fluid drainage system. This blockage leads to a significant increase in intraocular pressure, causing pain and potentially irreversible vision loss.
The new vessels are also prone to bleeding, which can result in a vitreous hemorrhage. This occurs when blood leaks into the vitreous, the jelly-like substance filling the eye, leading to sudden blurry vision or new floaters. In some cases, the abnormal vessels and associated scar tissue can pull on the retina, causing a retinal detachment, which can severely impair vision.
Patients experiencing rubeosis may notice symptoms such as:
- Blurry vision
- Eye pain
- Redness in the eye
- Seeing halos around lights
Management Approaches
Treatment for rubeosis aims to halt the growth of new vessels and manage any existing complications. Anti-VEGF injections are a first-line treatment, using medications like bevacizumab (Avastin), ranibizumab (Lucentis), or aflibercept (Eylea). These drugs work by inhibiting vascular endothelial growth factor, reducing the stimulus for new vessel formation and causing existing abnormal vessels to regress.
Panretinal photocoagulation (PRP) laser surgery is another treatment. It involves applying laser burns to the ischemic areas of the retina. This process destroys unhealthy retinal tissue, reducing the production of growth factors and decreasing the drive for new vessel growth. PRP is a standard approach for managing rubeosis secondary to proliferative diabetic retinopathy.
If neovascular glaucoma develops, management may involve eye drops to lower intraocular pressure, though controlling pressure can be challenging with this type of glaucoma. Surgical procedures, such as glaucoma drainage device implantation or cyclophotocoagulation, may be necessary in severe cases to help reduce eye pressure by decreasing fluid production. For complications like severe vitreous hemorrhage or retinal detachment, a vitrectomy may be performed, which involves surgically removing the vitreous gel and any blood or scar tissue. Managing the underlying cause, especially strict control of blood glucose levels in diabetic patients, is important to prevent the recurrence and progression of rubeosis.