Chorioretinopathy is a group of disorders affecting the back of the eye, causing damage to the retina and the choroid. The retina is the light-sensitive tissue lining the eye, and the choroid is a layer of blood vessels that supplies oxygen and nutrients to the outer retina. The choroid’s health is directly connected to retinal function.
The layer of cells separating the choroid from the retina is the retinal pigment epithelium (RPE). This layer acts as a barrier, and when it malfunctions, fluid from the choroid can seep underneath the retina. This fluid accumulation leads to a physical separation of the retinal layers, which disrupts the normal processing of light and results in visual disturbances.
Causes and Risk Factors
The origins of chorioretinopathies are varied, often stemming from inflammation, infection, or unknown (idiopathic) causes. A well-documented trigger is the use of corticosteroid medications. These drugs, whether taken as pills, inhaled through nasal sprays, or applied as skin creams, can initiate or worsen certain types of chorioretinopathy.
A strong association exists with elevated psychological stress. It is theorized that the body’s natural production of corticosteroids during intense stress may trigger the disease in susceptible individuals. This link is particularly noted in individuals with “Type A” personality traits, who are ambitious, competitive, or impatient.
Other contributing factors can include pregnancy, hypertension, and sleep disturbances like sleep apnea. Certain medications besides corticosteroids, such as stimulants and decongestants, may play a role. In some instances, a genetic predisposition may be involved, as about half of patients with one common form have a relative with similar findings.
Common Types of Chorioretinopathy
One of the most common forms is Central Serous Chorioretinopathy (CSC). This condition involves fluid accumulation under the macula, the central part of the retina responsible for sharp, detailed vision. The leakage causes a blister-like swelling that distorts the retinal surface. CSC most often affects men between the ages of 30 and 50 and is strongly associated with stress and corticosteroid use.
Another type is Birdshot Chorioretinopathy, a rare and chronic inflammatory disease that affects both eyes. It is named for the characteristic pattern of small, oval, cream-colored spots scattered across the choroid. This autoimmune condition is strongly linked to a specific genetic marker, HLA-A29, and primarily affects individuals of Northern European descent. The inflammation is T-cell mediated and can lead to retinal vascular leakage.
Multifocal Choroiditis and Panuveitis (MCP) is another inflammatory disorder characterized by multiple lesions affecting the choroid and retina. Unlike Birdshot, MCP tends to affect younger, nearsighted women. A related but distinct condition, Punctate Inner Choroidopathy (PIC), also causes small lesions and primarily affects a similar demographic, though it is less likely to recur.
Symptoms and Diagnostic Process
Individuals with a chorioretinopathy often experience a range of visual disturbances. A common symptom is blurred or distorted central vision (metamorphopsia), where straight lines may appear wavy or bent. Patients might also notice a dark or gray spot in their central field of vision, a scotoma. In some cases, objects may seem smaller or farther away, a perceptual distortion called micropsia.
To confirm a diagnosis, an ophthalmologist performs a comprehensive eye examination. An important diagnostic tool is Optical Coherence Tomography (OCT). This non-invasive imaging technique uses light waves to create detailed, cross-sectional pictures of the retina. An OCT scan can precisely visualize the location and amount of fluid buildup and reveal structural changes.
Another diagnostic procedure is Fluorescein Angiography (FA). This test involves injecting a dye into a vein in the arm, which then circulates to the blood vessels in the eye. A specialized camera takes photographs as the dye passes through the choroid and retina, highlighting any points of leakage. In some cases, Indocyanine Green Angiography (ICGA) is used to get a better view of the deeper choroidal circulation.
Management and Treatment Approaches
The approach to managing chorioretinopathy depends on the specific type, its severity, and whether the condition is acute or chronic. For many initial cases of Central Serous Chorioretinopathy, observation is the first step. The fluid leakage frequently resolves on its own over a few weeks to months. During this time, patients are counseled to modify risk factors, such as discontinuing corticosteroid use under their physician’s guidance.
If the fluid persists for more than three months or if vision is significantly affected, active treatments may be considered. One option is Photodynamic Therapy (PDT), which uses a light-activated drug (verteporfin) and a low-energy laser to help close leaking vessels in the choroid. Another laser-based option, focal laser photocoagulation, can be used to seal specific leak points located away from the center of the macula.
For chorioretinopathies driven by inflammation, such as Birdshot Chorioretinopathy, treatment focuses on controlling the body’s immune response. This often involves systemic medications like corticosteroids or other immunosuppressive drugs. In certain chronic cases or when complications arise, injections of anti-VEGF medications directly into the eye may be utilized to reduce fluid leakage and preserve vision.