Neovascularization of the eye is the abnormal growth of new blood vessels within the eye, often in the retina, choroid, or cornea. This condition typically arises from underlying diseases or injuries and can lead to severe vision impairment and loss.
What is Neovascularization in the Eye?
Neovascularization involves the pathological formation of new blood vessels from pre-existing ones. Unlike the body’s natural angiogenesis for healing, ocular neovascularization is an unregulated process. These new vessels are often fragile and prone to leakage, bleeding, or developing fibrous scar tissue. Such issues can disrupt the eye’s delicate tissues, potentially leading to inflammation and scarring.
Common Eye Conditions Associated with Neovascularization
Neovascularization is a common feature in several serious eye diseases.
Wet age-related macular degeneration (AMD) is a leading cause of vision loss in individuals over 50. It is characterized by abnormal blood vessel growth, known as choroidal neovascularization (CNV), beneath the macula. These fragile vessels often leak fluid or blood, damaging the macula and causing rapid central vision loss. This growth is often triggered by high levels of vascular endothelial growth factor (VEGF), a protein that promotes blood vessel formation.
Diabetic retinopathy, particularly proliferative diabetic retinopathy (PDR), is another significant condition. Prolonged high blood sugar damages existing retinal blood vessels, leading to inadequate blood supply. In response to oxygen deprivation, the eye releases VEGF, stimulating the growth of new, abnormal blood vessels on the retina’s surface or optic disc. These new vessels are fragile and can bleed into the vitreous or cause tractional retinal detachment, leading to significant vision impairment. Retinopathy of prematurity (ROP) and retinal vein occlusions are other conditions that can also involve abnormal vessel growth.
How Neovascularization Affects Vision
Individuals with ocular neovascularization may notice blurry vision, distorted images, or dark spots in their central vision. Vision loss can occur suddenly, especially if fragile new vessels bleed into the vitreous, the clear gel filling the eye. This leakage can also lead to fluid accumulation in the retina, causing swelling known as macular edema.
The formation of fibrous scar tissue alongside these abnormal vessels can also pull on the retina, potentially causing a retinal detachment. An eye care professional diagnoses neovascularization through a comprehensive eye examination. Common diagnostic tests include optical coherence tomography (OCT), which provides detailed cross-sectional images of the retina, and fluorescein angiography (FA), which involves injecting a dye into the bloodstream to visualize blood vessel leakage and abnormal growth patterns. OCT angiography (OCTA) is also used to identify abnormal blood vessels.
Treatment Options for Ocular Neovascularization
Treatment for ocular neovascularization focuses on inhibiting the growth and leakage of abnormal blood vessels. Anti-VEGF (vascular endothelial growth factor) injections are the primary treatment for conditions like wet AMD and diabetic retinopathy. These medications, such as aflibercept (Eylea), ranibizumab (Lucentis), and bevacizumab (Avastin), work by blocking VEGF, a protein that promotes new blood vessel formation and leakage. The injections are administered directly into the eye after numbing it.
Laser photocoagulation is another treatment option, used for sealing leaking vessels or slowing abnormal vessel growth. This procedure uses a laser to create small burns on the retina, destroying abnormal vessels. For more severe complications, such as significant bleeding into the vitreous (vitreous hemorrhage) or retinal detachment caused by scar tissue, vitrectomy surgery may be necessary. This surgical procedure involves removing the vitreous gel to clear blood or scar tissue and reattach the retina. Early detection and timely treatment are important to prevent further vision loss.
Living with Ocular Neovascularization
Living with ocular neovascularization requires ongoing management and close monitoring by an eye care professional. Regular eye exams are important to track the condition’s activity and adjust treatment. Adherence to the prescribed treatment plan, often involving repeated injections, is important for stabilizing vision. While treatments manage the condition, recurrence is possible.
Lifestyle factors also support overall eye health and the management of underlying conditions. Managing systemic conditions like diabetes and hypertension through diet, exercise, and medication can help reduce the risk of exacerbating ocular neovascularization. Avoiding smoking is also advised, as it can increase the risk of complications. Home monitoring tests, such as the Amsler grid, can help individuals detect subtle vision changes between appointments, prompting earlier intervention.