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Chorioretinal Folds: Causes, Symptoms, and Care
What Are Chorioretinal Folds?
Chorioretinal folds form in specific tissue layers at the back of the eye. Understanding which layers are involved and how the folds develop helps explain why a thorough diagnostic workup is so important.
The back of the eye contains several thin, precisely arranged layers. Chorioretinal folds affect Bruch's membrane (a thin separating layer between the choroid and the retinal pigment epithelium), the choroid (a blood vessel-rich tissue beneath the retina), the retinal pigment epithelium (RPE, a single cell layer that nourishes and supports the retina above it), and in many cases the neurosensory retina itself. When these layers buckle, they create the characteristic wave-like pattern a specialist can see during examination. The term 'chorioretinal' reflects that both the choroid and the retina are involved in the fold pattern.
Chorioretinal folds form when a physical force compresses or pushes against the inner surface of the sclera, which is the firm white outer wall of the eye. This compression causes the overlying tissue layers to buckle and form ridges, similar to pressing on the underside of a thin, flexible sheet. Two main forces can produce this effect: swelling or expansion of the choroid, which forces the layers above it to ripple, and mechanical strain between the sclera and choroid caused by scleral thickening or shrinkage. Both mechanisms ultimately produce the same visible rippling pattern.
Not all folds are identical in their depth or extent. Choroidal folds involve only the choroid and Bruch's membrane. Chorioretinal folds extend further, reaching into the overlying retinal layers. This distinction is clinically meaningful because deeper involvement of the retina may carry a greater risk of vision changes over time, particularly when the central macula is affected. A retina specialist uses imaging studies to determine exactly which layers are involved and how extensive the folds are.
What Causes Chorioretinal Folds?
Chorioretinal folds are associated with a broad range of conditions. Whether the folds appear in one eye or both provides one of the first and most important clues when searching for an underlying cause.
Bilateral chorioretinal folds, meaning folds in both eyes, most often point to a systemic or widespread condition. The most commonly identified causes include age-related macular degeneration (AMD), hyperopia (farsightedness caused by a shorter-than-normal eye), and idiopathic folds (folds with no clearly identifiable cause, which represent a meaningful proportion of bilateral cases). Other recognized bilateral causes include the following.
- Hypotony, meaning abnormally low pressure inside the eye
- Scleritis, or inflammation of the sclera
- Thyroid eye disease
- Uveitis, or inflammation inside the eye
- Choroiditis, or inflammation of the choroid layer
Among all cases of chorioretinal folds, idiopathic folds and those related to progressive hyperopia from a shortened eye are among the most common overall findings.
Unilateral chorioretinal folds, meaning folds in one eye, are more likely to have a localized cause. A retina specialist will evaluate for the following conditions when folds are present in only one eye.
- Posterior scleritis
- Hypotony following eye surgery or trauma
- Retinal vascular occlusion, which is a blockage of a blood vessel supplying the retina
- Intraocular tumors
- Age-related macular degeneration
- Optic nerve edema, meaning swelling of the optic nerve
- Retinal detachment
The one-sided nature of unilateral folds often helps narrow the diagnostic focus and guides the sequence of further testing.
A range of other conditions have also been linked to chorioretinal folds. These include orbital tumors (growths in the tissue directly behind the eye), infections, immunologic disorders, uveal effusion syndrome (fluid accumulation beneath the retina), and trauma to the eye. Intracranial hypertension, meaning increased pressure around the brain and spinal cord, is a well-recognized cause that frequently produces folds alongside papilledema, which is swelling of the optic disc at the back of the eye. Identifying these less common causes may require systemic testing beyond standard eye imaging.
One newer recognized cause is spaceflight-associated neuro-ocular syndrome (SANS). Astronauts on long-duration missions can develop choroidal thickening and optic disc swelling due to fluid redistribution in a microgravity environment, leading to chorioretinal fold development in some individuals. While this cause affects only a very small number of people, research into SANS has expanded the scientific understanding of the mechanical forces that drive fold formation more broadly.
Symptoms and What to Watch For
Chorioretinal folds can range from entirely silent to visually significant. The location of the folds within the eye plays a large role in determining whether or how much vision is affected.
Many patients with chorioretinal folds have no visual complaints at all and are unaware of the folds until they are discovered during a routine dilated eye examination. When the folds are positioned outside the macula (the central part of the retina responsible for sharp, detailed vision), central vision may remain fully intact. In these cases, the primary value of the diagnosis lies in identifying and monitoring the underlying condition before complications develop.
When symptoms do occur, the two most frequent complaints are blurred vision and metamorphopsia. Metamorphopsia is a form of visual distortion in which straight lines appear wavy or bent, similar to the effect of looking through rippled glass. Some patients also notice a gradual shift toward farsightedness. This can happen because the undulations in the retinal surface subtly alter the way light focuses inside the eye. Any new or worsening visual distortion should be evaluated promptly.
Chorioretinal folds that persist for a prolonged period can cause lasting changes in the affected tissue layers. Chronic folds may lead to atrophy (thinning) of the RPE, structural damage to Bruch's membrane, and eventually choroidal neovascularization (CNV), which is the growth of abnormal new blood vessels beneath the retina. CNV can cause significant and rapid vision loss if not detected and treated in time. Long-standing macular involvement may result in a condition called chorioretinal folds-related maculopathy, reflecting permanent structural changes to the central retinal tissue.
Beyond the folds themselves, a retina specialist may identify related findings during examination that help refine the diagnosis and guide treatment decisions. These associated findings can include the following.
- Retinal hemorrhages, or small areas of bleeding, often near the optic nerve
- Subretinal edema, meaning fluid accumulation beneath the retina
- Macular edema, or swelling within the central retina
- Macular exudates, which are deposits of fluid and protein in the retinal tissue
- Disorganization of the inner retinal layers, visible on imaging
Each of these findings contributes to a more complete picture of what is happening in the eye and what level of intervention may be needed.
How Chorioretinal Folds Are Diagnosed
Diagnosis combines a careful clinical examination with specialized imaging and, when needed, systemic testing. Finding the underlying cause sometimes requires more than one visit, particularly when folds are present in both eyes or no cause is immediately apparent.
The first step is a thorough dilated eye examination. After dilating drops widen the pupil, a retina specialist uses specialized lenses and a bright light to view the retina in detail. The folds appear as alternating light and dark bands on the retinal surface. Their pattern, location, orientation, and number provide important initial clues about the likely cause. A complete medical and ocular history is equally essential. Information about thyroid disease, prior eye surgery, headaches, use of certain medications, or any history of eye trauma all helps shape the diagnostic approach.
Optical coherence tomography (OCT) is a noninvasive, painless imaging test that produces detailed cross-sectional views of the retina and choroid. It clearly shows the undulations in Bruch's membrane, the RPE, and the retinal layers above. OCT can also detect subretinal fluid, macular edema, changes in choroidal thickness, and early signs of RPE damage or choroidal neovascularization. Because it is fast and requires no injection or contact with the eye surface, OCT is an essential tool for both the initial evaluation and all subsequent follow-up monitoring.
Fluorescein angiography involves injecting a fluorescent dye into a vein in the arm. A specialized camera captures a series of images as the dye circulates through the blood vessels of the eye. In patients with chorioretinal folds, the angiogram reveals alternating bright and dark bands corresponding to the peaks and valleys of the folds, and the test is particularly useful for detecting CNV or vascular changes. When an orbital tumor or intracranial cause is suspected, B-scan ultrasonography (an ultrasound of the eye and surrounding tissue) and MRI of the brain and orbits may also be ordered to evaluate structures that cannot be seen directly during the eye exam.
Because hyperopia from a short eye is among the more common causes of chorioretinal folds, measuring the axial length of the eye using a biometer can provide valuable information. A new or progressive shift toward farsightedness, especially when it has changed recently, may prompt closer investigation. Comparing measurements between the two eyes can reveal asymmetry that helps confirm or rule out a specific diagnosis. A formal refraction (the process used to determine an eyeglass prescription) is typically performed as part of this evaluation as well.
Treatment Approaches
Chorioretinal folds themselves generally do not require direct treatment. The goal of care is to identify and manage the condition responsible for the folds. Treatment plans are always individualized based on each patient's specific diagnosis, overall health, and visual needs.
Because folds arise from such a wide range of causes, the treatment approach varies considerably from patient to patient. When posterior scleritis is responsible, anti-inflammatory or immunosuppressive medications may reduce the underlying inflammation and allow the folds to flatten over time. When hypotony after eye surgery is the cause, restoring normal intraocular pressure is the priority. When a tumor or systemic condition is identified, the appropriate specialist is brought in as part of a coordinated care team. Addressing the root cause gives the folds the best opportunity to improve.
When intracranial hypertension is the cause, treatment may include acetazolamide, a medication that reduces the production of cerebrospinal fluid (the fluid surrounding the brain and spinal cord). Clinical research has demonstrated that acetazolamide can produce a meaningful reduction in chorioretinal fold frequency when compared to placebo in patients with this condition. However, research has also found that some folds may persist even after significant improvement in optic nerve swelling, suggesting that long-standing folds can cause lasting changes in the retinal tissue. This reinforces the value of early diagnosis and treatment before permanent changes develop.
If chronic chorioretinal folds lead to choroidal neovascularization, treatment with anti-VEGF (anti-vascular endothelial growth factor) injections is typically recommended. These medications block the protein signal that drives abnormal blood vessel growth beneath the retina, helping to stabilize or improve vision and prevent further retinal damage. A retina specialist will select the most appropriate medication and treatment schedule based on each patient's clinical findings and response to therapy.
When chorioretinal folds are mild, stable, and not causing any visual symptoms, a retina specialist may recommend a structured monitoring approach rather than immediate intervention. This is common in idiopathic cases and in patients with mild folds related to hyperopia. Regular dilated eye exams and OCT imaging allow the specialist to track any progression and intervene early if complications begin to develop. Monitoring is not passive: it requires a consistent schedule and prompt reporting of any new or changed visual symptoms between visits.
Living with Chorioretinal Folds
For many patients, chorioretinal folds are manageable and do not significantly interfere with daily life. Knowing how to monitor vision at home and how to stay engaged with related health conditions is an important part of protecting long-term outcomes.
Patients with mild folds that do not involve the macula often experience little or no disruption to everyday activities such as reading, driving, or using screens. When folds do involve the macula, central vision may become blurry or distorted, which can affect tasks that depend on fine detail. Working closely with a retina specialist to understand which activities are safe, what visual changes to watch for, and when to call for an unscheduled visit helps patients feel more confident in managing their condition over time.
An Amsler grid is a simple printed or digital grid that patients can use at home to check for changes in central vision. Each eye is tested separately, and the patient notes whether the grid lines look straight or distorted and whether any area of the grid appears missing or blurry. Patients with macular involvement are often advised to use this tool regularly between appointments. If lines appear newly wavy, a blank spot develops, or vision seems noticeably worse, the patient should contact their retina specialist promptly rather than waiting for the next scheduled visit.
Because chorioretinal folds are almost always a sign of another underlying condition, managing overall health is a key part of protecting the eyes. Patients with thyroid eye disease should maintain their relationship with an endocrinologist (a specialist in hormonal conditions) and report any changes in eye position, double vision, or visual clarity. Those being treated for intracranial hypertension should follow their medical plan consistently and report new headaches, vision changes, or other neurological symptoms without delay. Patients with AMD should adhere closely to their retina specialist's schedule for monitoring and treatment.
When to Seek Evaluation
Knowing when to pursue a routine evaluation and when to seek immediate care is essential for protecting vision when chorioretinal folds are present or suspected.
A referral to a retina specialist is appropriate whenever chorioretinal folds are identified during any eye examination. The range of possible underlying causes is wide, and some are serious conditions that respond best to early intervention. Patients with known risk factors, including hyperopia, thyroid eye disease, scleritis, or a history of intracranial hypertension, should have regular dilated eye examinations even when no visual symptoms are present. Early detection supports earlier treatment and a better chance of preserving long-term vision.
Some symptoms should not wait for a scheduled appointment. Patients should seek prompt care if they notice a sudden increase in floaters, new flashes of light, a curtain or shadow spreading across any part of their vision, or sudden vision loss in one eye. These symptoms may indicate a serious complication such as retinal detachment or active choroidal neovascularization. New or rapidly worsening metamorphopsia (wavy or distorted central vision) should also be evaluated without delay, as it may signal a developing complication that requires timely treatment to prevent lasting vision loss.
Frequently Asked Questions
Here are answers to questions our patients and referring providers commonly ask about chorioretinal folds.
Folds may improve or partially resolve when the underlying cause is successfully treated. Folds caused by posterior scleritis, for example, can diminish once inflammation is well-controlled, and those related to post-surgical hypotony may improve once eye pressure is restored. However, folds that have been present for a long time may cause lasting changes in Bruch's membrane and the RPE, meaning they may not fully disappear even after the root cause is corrected. This is one of the key reasons early diagnosis and treatment matter: the sooner the underlying condition is addressed, the better the chance that the folds can improve.
No. Chorioretinal folds and macular pucker (also called epiretinal membrane) are distinct conditions with different origins. Chorioretinal folds originate below the retina, arising from changes in the choroid and Bruch's membrane. Macular pucker involves a thin fibrous membrane that grows on the inner surface of the retina, pulling it out of its flat position. Both can cause visual distortion, which is why patients sometimes confuse them. OCT imaging allows a retina specialist to clearly differentiate between the two, because the location and character of the abnormality on the scan are quite different.
Not necessarily. Many patients with chorioretinal folds retain good vision, particularly when the folds are located outside the central macula and when the underlying cause is identified and managed early. Vision loss becomes a concern when folds are chronic, involve the macula, and progress to complications such as RPE atrophy, Bruch's membrane damage, or choroidal neovascularization. Regular monitoring is the most effective strategy for detecting these complications before they cause meaningful or permanent changes to vision.
Yes. AMD is one of the more frequently identified causes of chorioretinal folds, particularly in cases where both eyes are affected. Structural changes in the choroid and Bruch's membrane that accompany AMD can contribute to fold formation. Patients who have both conditions may require closer monitoring and may face a higher risk of developing choroidal neovascularization. A retina specialist can manage AMD and chorioretinal folds together, adjusting the treatment plan as either condition changes over time.
The initial workup typically includes a dilated eye exam, OCT imaging, and in many cases fluorescein angiography. From there, the testing is guided by whether folds are in one eye or both, the pattern and location of the folds, and the patient's medical history. B-scan ultrasonography may evaluate the sclera and tissue behind the eye. Biometry can measure axial eye length to help identify hyperopia-related folds. MRI of the brain and orbits is considered when intracranial hypertension or an orbital tumor is suspected. Blood work for thyroid function or systemic inflammatory markers may also be part of the workup. A retina specialist will sequence these tests based on clinical findings rather than ordering all of them at once.
Follow-up frequency depends on the cause, the stability of the folds, and whether any complications have been identified. Patients with mild, stable, idiopathic folds may need follow-up only every six to twelve months. Those with active underlying conditions, macular involvement, or a history of choroidal neovascularization typically need more frequent monitoring. A retina specialist will tailor the schedule to each patient's individual situation and will adjust it over time as the clinical picture evolves. Patients are always encouraged to report new or worsening symptoms between scheduled visits rather than waiting.
Expert Retina Care at New England Retina Associates
New England Retina Associates is a retina-only practice with fellowship-trained vitreoretinal specialists who bring extensive experience and advanced diagnostic technology to every evaluation of chorioretinal folds and the conditions behind them. We know that an unfamiliar finding can feel unsettling, and we are committed to providing clear, compassionate, and thorough care from the first visit through long-term monitoring. We welcome referrals from eye care providers throughout the region, and we also see patients who come to us directly seeking expert retinal care.
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