Angioid streaks are small, irregular breaks in Bruch’s membrane, a supportive layer of tissue deep in the eye’s retina. These breaks appear as dark, jagged lines radiating from the optic nerve, similar to cracks in dried paint. As a clinical sign of structural weakness in this retinal layer, they are often discovered during routine examinations because the streaks themselves do not produce symptoms.
Associated Systemic Conditions
While angioid streaks can develop without a clear cause (idiopathic), they are frequently linked to systemic diseases that impact the body’s elastic tissues. Over half of all cases are associated with an underlying disorder, prompting a thorough medical evaluation upon their discovery.
The most common condition is pseudoxanthoma elasticum (PXE), a genetic disorder that causes the mineralization and fragmentation of elastic fibers in the skin, cardiovascular system, and eyes. The weakening of Bruch’s membrane in individuals with PXE makes it susceptible to the crack-like ruptures that form angioid streaks.
Other systemic conditions are also linked to the formation of these streaks. A helpful mnemonic for remembering the primary associations is “PEPSI”:
- Pseudoxanthoma elasticum
- Ehlers-Danlos syndrome, a group of inherited disorders affecting connective tissues
- Paget’s disease of bone, which disrupts the normal cycle of bone remodeling
- Sickle cell disease and other blood disorders
- Idiopathic, where the cause is unknown
Visual Symptoms and Complications
While angioid streaks themselves do not interfere with vision, they create weak points in the retina susceptible to damage that can lead to visual disturbances. The primary concern is the development of a complication called choroidal neovascularization (CNV), which occurs in a high percentage of cases.
CNV is the growth of new, abnormal blood vessels from the choroid, the layer just beneath Bruch’s membrane. These fragile vessels can break through the cracks, leaking fluid or blood under the retina. This leakage can cause scarring and detachment of retinal photoreceptors, which can permanently affect central vision if the macula is involved.
The onset of CNV is what causes noticeable symptoms. Individuals may experience a sudden blurring or distortion of their central vision (metamorphopsia), where straight lines appear wavy or bent. Another common symptom is the appearance of a dark or blind spot (scotoma) in the central field of view. These symptoms signal active leakage and require prompt evaluation by an eye care specialist.
Diagnosis and Monitoring
The initial identification of angioid streaks is made during a dilated fundus examination, where an ophthalmologist views the back of the eye. The streaks appear as reddish-brown or gray lines radiating from the optic nerve. While they can be diagnosed clinically, further imaging is used to confirm their presence and monitor for complications like CNV.
Optical Coherence Tomography (OCT) is a non-invasive imaging technique that provides high-resolution, cross-sectional images of the retina. This scan functions like an ultrasound, using light waves to create a detailed picture of the retinal layers. OCT can detect subtle disruptions in Bruch’s membrane and is effective at identifying fluid or blood accumulation from CNV.
Another diagnostic tool is Fluorescein Angiography (FA). This procedure involves injecting a dye into a vein in the arm. As the dye circulates, a special camera takes photographs of the retinal blood vessels to pinpoint the exact location of leaking vessels associated with CNV.
Regular monitoring is also a component of care. Patients are often instructed to use an Amsler grid at home to check daily for any new or worsening visual distortions, which could indicate the onset of CNV.
Treatment Approaches
There is no treatment that can repair the angioid streaks themselves. Management strategies focus on addressing the vision-threatening complications that arise from them, specifically choroidal neovascularization (CNV). The goal is to prevent further vision loss by stopping leakage from the abnormal blood vessels.
The primary treatment for CNV is intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) medications. These drugs are administered directly into the eye and work by blocking the protein that stimulates the growth of new, leaky blood vessels. This therapy can reduce fluid accumulation and, in some cases, improve vision, but it requires ongoing treatment and regular follow-up.
Beyond medical interventions, preventative measures are also part of managing this condition. Because the weakened Bruch’s membrane is susceptible to rupture from physical impact, individuals with angioid streaks are advised to wear protective eyewear during sports or any activity that carries a risk of eye injury. Even minor trauma can cause a choroidal rupture and sudden vision loss.