What is Polypoidal Choroidal Vasculopathy?
Polypoidal choroidal vasculopathy (PCV) is a condition that affects the macula, the part of the eye related to vision quality. This condition causes several fluid-filled and blood-filled pockets to form under the retina and detachment of the retina. It has similarities in appearance to neovascular age-related macular degeneration, a condition that causes vision loss. The PCV was first identified by Yannuzzi and his team at a meeting for ophthalmologists in 1982. They originally named it idiopathic polypoidal choroidal vasculopathy (IPCV). In 1984, Kleiner and his team found a similar condition in middle-aged black women, which they named posterior uveal bleeding syndrome (PUBS). Later, Yannuzzi and his team provided a detailed description of PCV, showing that the condition can occur in both men and women, people of different ages, and various races.
What Causes Polypoidal Choroidal Vasculopathy?
Polypoidal choroidal vasculopathy (PCV) is believed to be caused by abnormalities in the blood vessels inside a part of the eye called the choroid. These blood vessels form multiple small, polyp-like swellings, similar to tiny balloons, due to a faulty vascular lining. The cells that line these vessels are thinner and fewer in number compared to healthy blood vessels.
Conditions like high blood pressure, increased thickness of the blood, and a lower than normal number of platelets (cells that help your blood clot) have been linked to PCV.
It’s suggested that one way these polyp-like lesions might develop is when small veins form projections that look like polyps when they are squeezed by a hardened small artery at a point where they cross each other. The pressure from the hardened artery slows down the blood flow in the vein, leading to the breakdown of tissue and making it frail. Over time, this can lead to the formation of shapes that look like polyps, which are prone to leakage and bursting.
Risk Factors and Frequency for Polypoidal Choroidal Vasculopathy
PCV, or Polypoidal Choroidal Vasculopathy, is a disease that’s not very common among the general population. In Europe, it’s estimated that only 0.04% of people have it. However, it’s more prevalent in Asian communities compared to white ones. Studies have found that in populations with a certain type of age-related macular degeneration (nAMD), PCV can be found in:
- 7.8% of white individuals
- 23% to 54% of Japanese individuals
- 22.3% of Chinese individuals
- 24.6% of Korean individuals
This condition tends to show up earlier in life than nAMD, and is often diagnosed in people between 50 to 65 years old. The time it starts showing up tends to be later in life for Caucasians than for Asians. Both men and women can have PCV, but it’s about 4.7 times more common in women than men.
There’s some debate over whether PCV might be related to other diseases like low blood platelet count, sickle cell anemia, exposure to radiation, or high blood pressure. However, more research is needed to confirm any potential connections.
Signs and Symptoms of Polypoidal Choroidal Vasculopathy
Polypoidal choroidal vasculopathy (PCV) generally shows up first as a decrease in vision. Other early signs can include distorted vision, a dark spot in the center of your visual field, and seeing floaters or small specks. People who report these symptoms within three months usually have clearer vision. They might also show signs of leakage or bleeding under the retina. Chronic cases might have signs like lipid exudation or intraretinal cysts. Interestingly, people with PCV usually have better vision when they first discover the condition than those with typical age-related macular degeneration (AMD). That could be because the affected area is outside the center of the retina and because there are minimal changes within the retina.
PCV usually affects both eyes. In most cases, once one eye develops PCV, the other also eventually shows symptoms. It’s characterized by orange-red elevated lesions that might be small, medium, or large; the larger ones can be seen during a routine eye exam. These lesions are most commonly located in the macular region. But a study also reported macular involvement in about 69% of cases and peripapillary (around the optic disc) involvement in about 4.5% of cases. There might also be lesions in the middle area of the peripheral retina.
Other clinical signs include serous or serosanguineous pigment epithelial detachments (separation of the retina’s innermost layer), subretinal hemorrhage (bleeding under the retina), lipid exudation (leakage of fatty substances), and detachment of the affected area’s neurosensory layer (part of the retina).
PCV can be classified as follow:
- Quiescent: The presence of PCV-related polyps without obvious signs of subretinal detachment or bleeding.
- Active: PCV is considered active if any of the following is true: vision loss of 5 or more letters, OCT/FFA/ICGA evidence of activity such as subretinal or intraretinal fluid, pigment epithelial detachment, subretinal bleeding, or fluorescein leakage. Active lesions are classified as:
- Exudative
- Hemorrhagic
- Mixed
Testing for Polypoidal Choroidal Vasculopathy
Indocyanine green angiography (ICGA) is a favored imaging method for identifying Polypoidal choroidal vasculopathy (PCV). It’s a medical condition that affects the vessels in the eye. ICGA is opted over another technique called fluorescein angiography (FFA) for PCV diagnosis because of its unique benefits.
The ICGA uses a special green dye that absorbs and emits near-infrared light. This light can easily penetrate a layer called the retinal pigment epithelium (RPE). This capability of ICGA enables a more detailed view of your eye’s choroidal structures, the area often affected in PCV. Also, unlike the dye used in FFA, the dye used in ICGA doesn’t leak from tiny blood vessels, so doctors can see the affected areas more clearly.
ICGA remains the gold standard for diagnosing PCV and distinguishing it from similar conditions such as retinal angiomatous proliferation and typical Age-related macular degeneration (AMD).
Using ICGA, doctors look for several signs of PCV. These include the presence of an abnormal vascular network, bloated vessels at the edge of the network, and a halo of hyperfluorescent light around polyps — all appearing within the first six minutes of the procedure.
ICGA also captures the polyps’ pulsations, noticed using video imaging. Initial phases of ICGA show an abnormal branching vascular network. Shortly after, hyperfluorescent polyps lightened up, which leak and blur the halo around them.
Moreover, optical coherence tomography (OCT), another imaging method, offers specific features that hint at PCV. Although OCT alone can’t diagnose PCV, doctors use it alongside ICGA for disease monitoring and treatment response assessment. Some OCT features suggestive of PCV include sharp-peaked pigment epithelial detachments (PED), notched PED, a hyporeflective lumen or tunnel surrounded by a hyperreflective ring under the RPE, and a Double-layer Sign. The Double-layer sign points out the presence of an abnormal vascular network, and sharp peaked PED suggests a polyp. Also, the thickened underlying layer of the retina, as seen on OCT, supports a PCV diagnosis and rules out typical AMD where this layer is usually thin.
Lastly, FFA is essential during the initial presentation of the condition, as it helps identify leakage from the abnormal vascular network – a sign of active disease. However, it plays a minor role in identifying polyps. Additionally, compared to ICGA, FFA tends to overestimate the size of the lesion if a PED is also present at the lesion’s edge. This erroneous measurement happens because the PED appears hyperfluorescent, or extremely bright, in FFA.
Treatment Options for Polypoidal Choroidal Vasculopathy
Polypoidal choroidal vasculopathy (PCV) is a condition that affects the part of your eye known as the retina, causing abnormal blood vessels and growths or “polyps”. Treatment will depend on how active the disease is and where it’s located in your eye. Active disease shows signs like fluid in the retina, hemorrhage, or a drop in vision, while inactive disease doesn’t show these signs but still needs to be closely watched by a doctor.
Different treatments can be used depending on your specific situation:
1. Photodynamic Therapy: This is a treatment that works great on polyps either located in (subfoveal) or outside (extrafoveal) your field of central vision, as well as areas where abnormal blood vessels extend beneath your field of vision. It uses a special dye that is sensitive to light, which, when injected, gathers in the abnormal blood vessels. A diode laser then causes these abnormal blood vessels to clot and resolve. Since no two cases of PCV are alike, the size of the laser spot might vary depending on the extent of polyps and abnormal vessels.
2. Anti-VEGF Drugs: This kind of treatment helps reduce leaks from abnormal blood vessels and polyps, leading to less fluid and hemorrhage and help preserve your vision.
3. Thermal Laser: These are useful for polyps located outside of your field of vision. The heat from the laser helps produce a scar on the affected area, thereby helping in resolution.
4. Combination Therapy: This treatment approach uses anti-VEGF drugs and Photodynamic Therapy together to get the best results. This combination might lead to an improvement in your condition faster than using each treatment separately.
Your doctor will discuss these treatment options with you and suggest the best one for your specific case based on the nature and severity of your PCV. The ultimate aim is to manage your condition effectively and help maintain your vision.
What else can Polypoidal Choroidal Vasculopathy be?
Polypoidal choroidal vasculopathy (PCV) is quite similar to neovascular age-related macular degeneration (nAMD), but they are considered to be different conditions. Both diseases share common features, such as increased VEGF expression (substances that help form blood vessels), similar tissue changes, and antibody reactions. However, there’s less VEGF in PCV compared to nAMD.
In terms of physical signs, PCV polyps originate from the inner layer of the choroid and remain under the surface of the retinal pigment epithelium (RPE). The RPE is usually intact in PCV, which is different from nAMD, where tuffs of new blood vessels grow from the choroid into the space under the RPE or in the space below the retina. Special eye exam findings using optical coherence tomography (like a peak or notch in the pigment epithelial detachment, or the presence of a double-layer sign) can help differentiate PCV from nAMD.
PCV can sometimes be mistaken for Central Serous Chorioretinopathy (CSC), which is a condition that leads to a fluid pocket and macro detaching from the sensory neurons. The theory behind CSC is that it might be due to problems with the blood vessels in the choroid. This causes hyperpermeability (or excessive leaking) from the choroid, and impairs the function of the RPE, leading to fluid accumulation that eventually leaks into the space below the retina. Indocyanine green angiography – a special eye test using a green dye – can help doctors differentiate between CSC and PCV, as each condition shows different patterns on this test.
What to expect with Polypoidal Choroidal Vasculopathy
Generally, smaller growths in the eye that are less than one disc in diameter (about the size of an optic nerve head) usually have a good prognosis. This means that there’s minimal vision loss and a low risk of complications that could further endanger sight. However, there are certain factors which could lead to a worse outcome, these include larger growths, a condition termed as PED (which stands for Pigment Epithelial Detachment), cluster growths, if these growths are located in the macula (a part in the middle of the retina which provides central vision), being of the Caucasian race, and if these growths come back again.
Given this, doctors generally recommend regular follow-up checks for eyes with this condition (known as PCV, or Polypoidal Choroidal Vasculopathy), as there’s a significant number of cases where inactive growths can worsen over time, even if they appear to have been stable for years. Severe vision loss can happen in around one-third of eyes with PCV.
Possible Complications When Diagnosed with Polypoidal Choroidal Vasculopathy
PCV, or polypoidal choroidal vasculopathy, can cause a series of problems that affect your eyes. This condition can lead to a shortage of blood supply in the choroid (a part of the eye), inflammation, damage to the layer of cells that nourish your eyes’ retina (RPE), and tears in Bruch’s membrane (an important layer in your eye). These issues might result in the formation of abnormal blood vessels in your eye, scarring, and stiffening of tissues. The worst outcome from these chain reactions is the loss of vision, which unfortunately cannot be reversed.
Potential problems caused by PCV:
- Ischemia (shortage of blood supply) in the choroid
- Inflammation
- Damage to the RPE part of your retina
- Tears in Bruch’s membrane
- Formation of abnormal blood vessels (CNVM)
- Scarring and stiffening of tissues (fibrosis)
- Irreversible loss of vision
Preventing Polypoidal Choroidal Vasculopathy
Polypoidal choroidal vasculopathy is a condition that affects the eyes and is similar in its symptoms to a disease called neovascular AMD. Since it can seriously damage your eyes, it’s important that it’s diagnosed and treated quickly to help preserve your vision. Symptoms such as a sudden decrease in sight or distortion in your vision, need quickly evaluation with Optical Coherence Tomography (OCT), a non-invasive imaging test that captures detailed images of your eyes. In addition, starting treatment with a therapy called anti-VEGF can help prevent further damage and permanent scarring in the eyes.
Patients need to understand the importance of sticking to their treatment plan. Other treatments like Photodynamic Therapy (PDT) or thermal laser could possibly lessen or even eliminate the need for monthly injections directly into the eye, which could also lower the overall cost of treatment. It’s crucial for patients to know that any increase in vision problems in either eye needs to be checked out promptly, as delaying treatment can lead to permanent vision loss.
