Angioid

Angioid streaks are irregular, gray-to-reddish-brown, band-like lesions that extend radially from the optic disc. They are typically bilateral and occur in the mid-peripheral and peripheral retina. These streaks represent breaks in Bruch's membrane, the innermost layer of the choroid, which is a critical support structure for the retinal pigment epithelium.

The presence of angioid streaks is often associated with several systemic conditions. The most common is pseudoxanthoma elasticum, a genetic disorder characterized by calcification and degeneration of elastic fibers in various tissues. Other associated conditions include Ehlers-Danlos syndrome, Paget's disease of bone, and sickle cell disease. In some individuals, angioid streaks may occur without any identifiable systemic cause, a condition known as idiopathic angioid streaks.

While angioid streaks themselves are asymptomatic, they can lead to significant visual impairment due to complications. The most frequent complication is choroidal neovascularization, where abnormal blood vessels grow under the retina, leading to leakage and hemorrhage. This can cause rapid and severe vision loss. Other complications include retinal hemorrhages, macular edema, and subretinal fibrosis.

Diagnosis of angioid streaks is typically made during a dilated fundus examination. Optical coherence tomography (OCT) is a valuable imaging technique that can visualize the breaks in Bruch's membrane and detect associated neovascularization. Fluorescein angiography can also be used to highlight the streaks and identify active neovascularization.

Management of angioid streaks focuses on monitoring for and treating complications, particularly choroidal neovascularization. Anti-vascular endothelial growth factor (anti-VEGF) injections are the mainstay of treatment for neovascularization, aiming to reduce leakage and preserve visual acuity. Regular eye examinations are crucial for individuals with angioid streaks to detect and manage potential complications early.