Angioid Streaks

What is Angioid Streaks?

Angioid streaks are changes in an eye part called Bruch membrane, which becomes weak and calcified. This condition can cause bleeding in the retina, either happening on its own or after a blunt injury. Usually, these streaks form around the optic disc and spread outwards in a linear pattern. They can occur on their own or be connected to other systemic conditions such as pseudoxanthoma elasticum (PXE), Ehlers-Danlos syndrome, sickle cell disease, and Paget disease of the bone.

Angioid streaks can lead to fibrous tissue from the choroid (the vascular layer of the eye) invading the subretinal epithelial space (the layer under the retina). This invasion can result in bleeding, the formation of new blood vessels (neovascularization), and scarring, all of which can cause symptoms like distorted vision or decreased visual sharpness. People with this condition are at risk of bleeding under the retina, even from minor injuries.

Most people with angioid streaks have no symptoms. Those without symptoms only need to have their condition monitored. If new blood vessels form, early treatment with medicines to inhibit VEGF (vascular endothelial growth factor, which promotes the growth of new blood vessels) become the primary treatment. Combining light-activated treatments with medicines like bevacizumab can also help shrink the growth of new blood vessels in the choroid. During this time, wearing protective eyewear to avoid future injuries plays a key role in improving the overall outcomes and reducing the likelihood of future choroidal ruptures and bleeding.

What Causes Angioid Streaks?

Angioid streaks, which are essentially tiny red or brown lines that appear on the back of your eyeball, can either develop on their own or they can be linked to an underlying disease.

The most common disease they’re associated with is called pseudoxanthoma elasticum, or Grönblad–Strandberg syndrome. This condition is characterized by irregularities in the body’s connective tissue, like damaged elastic fibers and extra calcium deposits. This can happen due to a particular genetic mutation.

This mutation affects a gene called ABCC6, which controls a protein that helps regulate the amount of calcium and other minerals in the body’s connective tissues. If this protein doesn’t function correctly, it may lead to pseudoxanthoma elasticum.

There are other conditions apart from pseudoxanthoma elasticum which are commonly linked with angioid streaks. These include:

– Paget’s disease of the bone, which affects how quickly your bones remodel themselves
– Sickle cell disease and other red blood cell disorders
– Ehlers-Danlos syndrome, which affects your skin, joints and blood vessels

Though Ehlers-Danlos syndrome was historically associated with angioid streaks, newer research reveals that angioid streaks aren’t as common in people with this condition as initially thought.

Apart from the above conditions, angioid streaks can also appear in people with various other diseases such as:
– Marfan syndrome
– Acromegaly
– Hemochromatosis
– Diabetes
– Sturge Weber syndrome
– High myopia (nearsightedness)
– High phosphate levels in the blood
– Neurofibromatosis
– High calcium levels in the blood
– Familial polyposis of the colon (a condition which leads to the development of numerous polyps in the lining of the colon)
– Congenital hypertrophy of retinal pigment epithelium (a harmless condition where parts of the eye’s pigment layer are thicker than usual)
– Diffuse lipomatosis
– Cutaneous calcinosis
– Microsomia
– Trauma
– Hypertensive coronary artery disease
– Senile elastosis
– Epilepsy

Remember, having any of these conditions doesn’t automatically mean that you will develop angioid streaks – it just slightly increases the odds.

Risk Factors and Frequency for Angioid Streaks

Idiopathic angioid streaks, a condition of the eyes, generally start to show in the sixties, accounting for about half of all cases. However, people with certain underlying conditions might start seeing symptoms earlier. These streaks are quite common in certain conditions such as PXE (with about 87% of patients), Paget disease of the bone (about 10% of cases), and sickle cell disease (around 1% to 2% cases).

• People with PXE usually start showing symptoms in their thirties, with the average age being nearly 52.
• Those with sickle cell disease might start experiencing symptoms sometime in their twenties or thirties, with the average age being almost 42.
• Patients with Paget disease usually develop these streaks later in life, around the age of 67.

While there is no preference for gender in the occurrence of these streaks, they are more common in white people compared to Black and Asian individuals. A significant number of patients with these streaks lose their central vision due to a condition called choroidal neovascularization, which accounts for 70% to 86% of vision loss cases in affected patients.

Signs and Symptoms of Angioid Streaks

Angioid streaks often appear in both eyes and typically don’t cause vision problems unless they affect the central part of the retina or blood vessels grow abnormally in the macular region, a part of the retina responsible for detail vision. Symptoms like distorted vision and seeing objects smaller than they are could be early signs of issues in the macular area. Unless the central macula is involved, visual fields should still be normal. As vision becomes impaired, patients might lose color perception.

A doctor starts the investigation by conducting a thorough eye exam, which checks visual clarity, eye pressure, how well eyes move, the front and back of the eye and how well the pupils react to light. Take note, angioid streaks may not always be noticed initially due to their similarity to retinal blood vessels.

Angioid streaks have the following characteristics:

• Twisted irregular lines with jagged edges starting from the optic disc
• Similar varying size to retinal vessels between 50 to 500 µm
• Streaks located under the retina, often interconnected and forming a ring around the optic disc
• Colors range from gray, black, red to pink
• Macular region may be involved
• Abrupt tapering at the end farthest from the optic disc

As people age, the number, width, and length of these streaks might increase. Over time, they may not be as apparent but could appear as areas of dark pigmentation or the wasting away of the retina or choroid. Other features associated with angioid streaks include:

• An “orange peel” appearance of the backmost part of the eye, often seen temporal to the macula
• Optic disc drusen: Hyaline bodies that may also come before the presence of angioid streaks
• Optic nerve atrophy: Wasting away present in patients with Paget disease of the bone
• Macular thinning or pigmentary changes: Usually affects both eyes, without bleeding or hard exudates
• Subretinal or submacular bleed: Usually detected when a patient’s vision decreases abruptly

Severe loss of vision occurs in 70% of affected patients due to the following:

• Abnormal blood vessel growth in the choroid, leading to serous and hemorrhagic detachment of the fovea
• Choroidal rupture often as a result of minor trauma
• Streak damage to the retinal pigment epithelium and choriocapillaris, leading to permanent loss of central sharp vision

Pseudoxanthoma Elasticum (PXE) is characterized by abnormalities and fragmentation of elastic fibers in various body systems, including the skin, eyes, blood vessels, and intestines. Patients with PXE nearly always show angioid streaks within 20 years following their diagnosis. Skin lesions often first appear as yellowish or darker papules on the neck, then to other areas, leading to lax and saggy skin. A vision decline, irregular vision, glare, blind spots, flickering lights, and flashes could indicate acute retinopathy.

Aside from changes in the eyes, peripheral vascular symptoms include weak peripheral pulses, intermittent leg pain while walking, high blood pressure due to kidney problems, premature coronary artery disease, and cerebrovascular disease. Aneurysms in the brain, kidney, and mesentery can cause bleeding and rarely, intestinal pain and gastrointestinal bleeding because of mesenteric artery involvement.

Paget Disease and Sickle Cell Disease also show ocular manifestations associated with PXE.

Testing for Angioid Streaks

If your doctor thinks you might have certain health conditions like gastrointestinal bleeding, heart disease, anemia, or unusual bone breaks, they might do a general checkup. They will specifically check levels of calcium, phosphorous, and a type of protein called alkaline phosphatase in your blood. In persons with a condition called Paget disease of the bone, these levels can be abnormal. For a more detailed diagnosis, the doctor will take a picture of your bones using X-rays.

Now, if your X-ray results show signs of Paget disease, your doctor might recommend a radionuclide bone scan. This test uses small amounts of radioactive material to show how your skeleton is working. It can help determine how much of your bone is affected by the disease. Sometimes, a bone biopsy might be needed if the test results look unusual or point towards possible cancer spread.

PXE, or pseudoxanthoma elasticum, is diagnosed based on specific conditions or symptoms. You must have two from the following:

* Two major skin symptoms
* One major eye symptom
* Two harmful changes (mutations) in a specific gene (ABCC6)

The major skin symptoms are certain types of skin bumps and plaques on the neck, areas of the skin that bend easily, and signs of clumped and irregular (pleomorphic) elastic fibers under the skin. The major eye symptom is an eye condition called angioid streaks and a change in the coloring of the eye’s exterior seen in peau d’orange.

The minor conditions for PXE diagnosis include one of your close relatives, like a parent or sibling, having the disease, finding only one harmful gene change on testing, and specific changes of PXE on your skin, even if you don’t see any lesions.

The testing method for sickle cell disease, a genetic disorder that affects red blood cells, varies based on the patient’s age. DNA tests are used before the baby is born. After birth, the preferred method of diagnosis is high-performance liquid chromatography or electrophoresis. These tests can identify and measure different types of hemoglobin’s in the blood. In the United States, newborns are tested for sickle cell disease as part of standard screening.

If your doctor suspects ocular issues, particularly angioid streaks, several tests may be employed. Fluorescein angiography uses a dye to help visualize the blood vessels in your eye. This test can help identify any abnormalities suggesting disease. Indocyanine green angiography is particularly good at identifying new blood vessel formation in the eye, a condition known as choroidal neovascularization. In addition, an ultrasound may be done as it is capable of spotting specific eye-related changes in about 25% of PXE patients.

Another useful test is optical coherence tomography (OCT). OCT is a non-invasive imaging test that utilizes light waves to take cross-section pictures of your retina, the light-sensitive tissue lining the back of the eye. This test is particularly useful in monitoring the effectiveness of treatment.

Overall, these methods help physicians conduct investigations that may lead to the diagnosis of various diseases and direct the appropriate course of treatment.

Treatment Options for Angioid Streaks

Angioid streaks are unusual lines seen in the back of the eye. They usually don’t cause any symptoms and don’t need treatment. But, it’s important to know that they can make your eyes more vulnerable to bleeding underneath the retina if your eye gets hit or bumped. Because of this, it’s a good idea to wear protective glasses if you have angioid streaks.

If you have angioid streaks, doctors will also want to check you for any related health problems. They might also want to examine your family members, since they might also have these streaks or related illnesses.

If there’s bleeding under your retina, doctors will want to check for a condition called choroidal neovascularization. This means that new, weak blood vessels are growing underneath the retina. If you don’t have this condition, the bleeding usually goes away on its own. However, if you do have it, it can be quite serious and may lead to vision loss even with treatment.

Therefore, it’s very important to catch and treat choroidal neovascularization early. There are several treatment options available, including a kind of laser surgery, a procedure that uses a special kind of light to treat the new blood vessels, surgery that moves the central part of your retina, a procedure that transplants certain eye tissues, and medications that stop the growth of new blood vessels.

These medications include ones like ranibizumab, aflibercept, and bevacizumab. These have been approved by the US Food and Drug Administration (FDA) for use in several other eye conditions too. They have been successful in improving or stabilizing vision. Any of these medications can be effective in treating choroidal neovascularization and are often the first choice of treatment for this condition.

In the past, using laser treatment and a special kind of light treatment haven’t had very good results. However, new technologies have improved these treatments, and they may slow down the growth of new blood vessels and stabilize vision while not damaging the retina. But, these treatments may still need to be repeated quite often.

Another kind of treatment, called Transpupillary thermotherapy (TTT), can keep vision stable and initially decrease the size of angioid streaks. However, these streaks often increase in size again after 3 months. And so, TTT isn’t usually used in treating choroidal neovascularization associated with angioid streaks.

Lastly, there are surgical options available. These procedures can be considered if the condition doesn’t get better with other treatments. Surgery would only be considered as a last resort.

What else can Angioid Streaks be?

When looking at the unusual lines on the retina known as ‘angioid streaks’, doctors might consider these other possibilities:

• Normal blood vessels in the retina
• Cracks, known as ‘myopic lacquer cracks’, in the back of the eye due to severe nearsightedness (myopia)
• A retinal change that causes a ‘fishnet with knot’ pattern of pigmentation; this is called ‘reticular dystrophy of the retinal pigment epithelium’
• Smooth traces under the retina that may cross over each other, caused by parasitic infection of the eye (‘ophthalmomyiasis interna’)
• Bands under the retina resulting from a long-standing or surgically corrected detachment of the retina
• Scarring that appears like a hole-punched look, which resembles a condition called ‘presumed ocular histoplasmosis syndrome’
• A crack in the layer beneath the retina (‘choroidal rupture’)
• A condition where the central part of the retina leaks fluid (‘central serous retinopathy’)
• The hardening of the layer beneath the retina (‘choroidal sclerosis’)
• A serious eye condition where new blood vessels grow under the retina (‘exudative age-related macular degeneration’)
• A cancer that has spread to the layer beneath the retina (‘metastatic choroidal tumor’)
• An infection of the retina known as ‘toxoplasmosis’

What to expect with Angioid Streaks

Patients with a condition known as choroidal neovascularization usually have a poor vision outlook, whether they receive treatment or not. Essentially, choroidal neovascularization is a condition where new blood vessels grow in an area of the eye called the choroid, distorting vision over time.

This issue will develop in 72% to 86% of patients who have ‘angioid streaks,’ which are small breaks in a particular layer of the eye. Once these new blood vessels develop in one eye, there’s a 50% chance it will also occur in the other eye within the next 18 months.

Additionally, 15% of people with this condition can experience significant vision loss from minor injuries. By the age of 50, most patients with a specific disease called PXE (which causes angioid streaks) often have a vision rating of 20/200 or worse. This means their vision is significantly impaired.

However, it’s not all bad news. Angioid streaks that are associated with sickle cell disease, a condition where the red blood cells become misshapen, often have a better outlook. Typically, these cases are harmless and the chances of developing choroidal neovascularization are low.

Possible Complications When Diagnosed with Angioid Streaks

Angioid streaks can lead to several complications:

• Bleeding under the retina due to a break in the blood vessels at the back of the eye after minor injury
• Abnormal blood vessel growth in the layer of blood vessels at the back of the eye
• Shrinkage and thinning of the small depression in the retina at the back of the eye
• Loss of vision

Preventing Angioid Streaks

Angioid streaks are the lines you sometimes see in your vision, which can appear without any clear reason or can be connected to a larger illness. This is why it’s important to have a thorough check-up to discover any other health problems that might be linked. Many people with these streaks don’t experience any problems, however, regular visits to the doctor to keep an eye on their condition are crucial.

Those with this condition must be aware of the chance that they could lose their vision because of an affected spot in the eye, or a condition where new blood vessels grow in the vision area. They should seek medical help immediately if they realize their eyesight is getting weaker, or if they have issues with seeing straight ahead, struggle to perceive depth or see distortion in lines and objects.

One potential risk is that even minor knocks can cause damage to an area of the eye and blood leakage under the retina, so protective eyewear, like sturdy goggles should be worn during activities where there’s a chance of injuring the eye or head – like playing sports.

Doctors need to stress the importance of seeing new blood vessels growing in the vision area at an early stage through regular eye exams. At home, people with this condition can use an Amsler grid, which helps monitor changes in vision and might encourage them to seek medical help sooner. Relatives of those with angioid streaks should also have a thorough eye examination to detect angioid streaks early and check for any linked health problems.