A conjunctival cyst is a noncancerous, fluid-filled sac that forms on the conjunctiva, the transparent membrane covering the white part of the eye and lining the inside of the eyelids. These common growths are generally harmless. The conjunctiva protects and lubricates the eye, acting as a barrier against irritants. Understanding these cysts can aid in their management.
Understanding Conjunctival Cysts
Conjunctival cysts appear as small, clear, or yellowish bumps on the eye’s surface. The conjunctiva is a mucous membrane containing blood and lymphatic vessels, which helps lubricate the eye and fight infections.
There are two primary types of conjunctival cysts. Inclusion cysts, accounting for over 80% of cases, form when a layer of the conjunctival epithelium folds over itself, creating a fluid-filled pocket. Retention cysts develop when a small duct in the conjunctiva becomes blocked, leading to an accumulation of cells and fluid from the lymphatic system.
These cysts can arise from various factors that irritate the eye. Common causes include inflammation, such as allergies, dry eyes, or conjunctivitis (pink eye). Trauma or injury to the eye, contact lens use, and complications following eye surgery, like cataract or strabismus procedures, can also lead to their formation. Some individuals may be born with conjunctival cysts, or they can develop spontaneously without a clear cause.
Signs and Diagnosis
Many small conjunctival cysts do not cause noticeable symptoms and may only be discovered during a routine eye examination. Larger cysts can lead to a foreign body sensation, making it feel like something is stuck in the eye. Other signs include mild irritation, redness, or discomfort.
In rare instances, if a cyst grows large enough to interfere with the visual axis, it might cause blurred vision. A swollen eyelid or difficulty closing the eye can also occur with larger cysts. Any new lump, persistent eye irritation, or changes in vision warrant a consultation with an eye care professional.
An eye care professional diagnoses a conjunctival cyst through a comprehensive eye examination. A slit lamp microscope is used, allowing for a magnified and detailed view of the cyst’s location, size, and characteristics. This instrument helps distinguish conjunctival cysts from other growths like pingueculae or pterygia. Additional imaging tests, such as ultrasound or magnetic resonance imaging (MRI), are generally not required but may be used in specific cases to rule out other conditions.
Treatment and Outlook
The management of conjunctival cysts varies depending on their size and whether they cause symptoms. Many small, asymptomatic cysts do not require active treatment and are simply monitored by an eye care specialist during regular eye exams. Over-the-counter eye drops or prescription corticosteroid drops might be suggested to lubricate the eye and reduce inflammation for mild irritation.
If a cyst is symptomatic or growing, drainage, also known as aspiration, can be performed. This procedure involves puncturing the cyst with a tiny needle to drain the fluid after numbing the eye with a local anesthetic. While less invasive, there is a higher chance of recurrence with aspiration because the cyst’s inner epithelial lining, which secretes fluid, may remain.
Surgical excision is considered for large, persistent, symptomatic, or recurrent cysts. This is a minor outpatient procedure where the cyst is carefully cut away from the conjunctiva. Techniques like staining the cyst wall with trypan blue or using laser assistance can help ensure complete removal and reduce recurrence risk, as incomplete excision is a common reason for the cyst to return.
The outlook for conjunctival cysts is favorable, as they do not pose a serious threat to vision. A full recovery is expected, even after surgical removal. However, recurrence is possible, especially if the original cause of irritation persists or if the cyst was not completely removed.
Individuals should seek professional medical advice if they experience persistent discomfort, a significant increase in cyst size, changes in vision, pain, or any new or worsening eye symptoms. These signs could indicate the need for intervention or further evaluation to ensure appropriate management.