Conjunctival Cyst: Symptoms, Types, Causes and Treatment

Conjunctival cysts are fluid-filled sacs that develop on or under the conjunctiva—the thin, transparent tissue covering the white part of the eye and the inside of the eyelids. While they are usually benign, their presence can be distressing due to discomfort, visual changes, or cosmetic concerns. In this article, we’ll explore the symptoms, types, causes, and treatment options for conjunctival cysts, synthesizing up-to-date research and clinical insights.

Symptoms of Conjunctival Cyst

Conjunctival cysts may go unnoticed in their early stages, but as they grow, various symptoms can become apparent. Understanding these symptoms helps patients and healthcare providers recognize when to seek further evaluation or intervention.

Symptom	Description	Frequency/Prevalence	Source(s)
Swelling	Visible bulge or lump on the eye or eyelid	Very common	1 2 3
Foreign body sensation	Feeling of something in the eye	Common	1
Cosmetic concern	Noticeable disfigurement, may affect confidence	Common	1
Ptosis	Drooping of the upper eyelid	Occasional	3
Ocular motility restriction	Difficulty moving the eye	Rare	1 2 3
Proptosis	Eye appears pushed forward (bulging)	Rare	1 3
Visual changes	Blurred or decreased vision	Rare	1
Irritation	Redness, mild discomfort or irritation	Occasional	1 3 9

Table 1: Key Symptoms

Common Presenting Symptoms

The most frequently reported symptom is a visible swelling or lump, which can occur on the surface of the eye, under the eyelid, or in the upper eyelid sulcus. Patients often notice a gradual increase in size, which can be alarming but is typically painless in the early stages 1 2 3.

Sensations and Discomfort

As the cyst enlarges, many individuals report a persistent sensation of something being in the eye, known as a foreign body sensation. While not always painful, this can cause significant irritation and may lead to rubbing or scratching, potentially exacerbating the issue 1 9.

Cosmetic and Functional Concerns

Cosmetic disfigurement is another significant concern, especially when the cyst is large or in a prominent location. Some cysts, particularly those in the upper orbit, can cause ptosis (drooping of the eyelid) or restrict eye movement, leading to difficulties with vision or even double vision (diplopia) in rare cases 1 2 3.

Rare but Serious Symptoms

Although uncommon, some conjunctival cysts can cause proptosis (eye bulging) or mild visual impairment if they become large enough to press on the eye or surrounding structures 1 3. These cases warrant prompt medical evaluation.

Types of Conjunctival Cyst

Conjunctival cysts are not all the same—they vary by origin, structure, and clinical behavior. Accurate classification is vital for determining appropriate management and prognosis.

Type	Defining Features	Relative Frequency	Source(s)
Primary Inclusion	Congenital, epithelial in origin	30% of studied cases	1 3 4
Secondary Inclusion	Acquired, following trauma or surgery	15%	1 5 8 11
Retention/Serous	Glandular blockage, retention of secretions	Frequent in adults	6 7
Parasitic	Caused by parasitic infection (rare)	10%	1 7
Lymphatic	Dilated lymphatic vessels, thin-walled	Uncommon (5%)	1 7
Dermoid/Epidermoid	Epithelial-lined, can contain appendages	Rare	2 4
Cysts with Pterygium	Associated with pterygium (growth on conjunctiva)	37.5%	1

Table 2: Types of Conjunctival Cyst

Primary vs. Secondary Inclusion Cysts

• Primary inclusion cysts are generally congenital and originate from sequestration of conjunctival epithelial tissue during development. These are often found in the upper orbit and may be present from birth or early childhood, though they sometimes remain unnoticed for years 1 2 3 4.
• Secondary inclusion cysts are acquired and most often develop following trauma, surgery (such as strabismus correction), or ocular injury. These cysts result from the implantation of conjunctival epithelium into deeper tissues 1 5 8 11.

Retention (Serous) and Glandular Cysts

These cysts form when the ducts of the conjunctival glands (such as Krause’s glands) become obstructed, leading to the accumulation of glandular secretions. They tend to occur in the conjunctival fornices and are more common in adults 6 7.

Parasitic and Lymphatic Cysts

• Parasitic cysts are extremely rare but may occur due to infections with parasites like Echinococcus or filarial worms 1 7.
• Lymphatic cysts arise from dilated lymphatic vessels and are lined by endothelium 1 7.

Dermoid and Epidermoid Cysts

These cysts are lined by epithelial tissue and may contain skin appendages. They are distinct from classic conjunctival cysts and are often located superonasally without associated bone defects 2 4.

Cysts with Pterygium

Some cysts form in association with a pterygium, a benign growth of conjunctival tissue. These account for a significant proportion of conjunctival cyst cases in some clinical studies 1.

Causes of Conjunctival Cyst

Understanding the diverse causes of conjunctival cysts is crucial for both prevention and treatment. The etiology often guides prognosis and management strategies.

Cause	Mechanism or Risk Factor	Typical Patient Profile	Source(s)
Congenital	Developmental sequestration of epithelium	Children, young adults	2 3 4 7
Trauma/Surgery	Implantation of epithelium during injury or procedure	All ages, post-surgical	1 5 6 8 11
Glandular Retention	Blockage of conjunctival gland ducts	Adults, elderly	6 7
Inflammation	Chronic conjunctivitis or irritation	Recurrent eye problems	6 7 9
Medication	Chronic use of preserved eye drops	Long-term users, allergies	9
Parasitic Infection	Infestation by parasites	Rare, endemic regions	1 7

Table 3: Causes of Conjunctival Cyst

Congenital Origin

Congenital cysts form when conjunctival epithelial cells are displaced during embryonic development. These are often found in the caruncle, plica semilunaris, or upper orbit, and may remain asymptomatic for years 2 3 4 7.

Trauma and Surgery

A leading cause of acquired conjunctival cysts is trauma—either accidental or surgical. Procedures such as strabismus surgery, enucleation (removal of the eye), or even minor injuries can introduce conjunctival epithelium into deeper tissues, leading to cyst formation 1 5 6 8 11.

• Notably, certain surgical techniques (e.g., muscle recession in strabismus surgery) may increase the risk of cyst development due to manipulation of conjunctival and Tenon’s tissues 8 11.

Glandular Retention and Inflammation

Blockage of the excretory ducts of conjunctival glands—often due to chronic inflammation or infection—can result in retention cysts. Agglutination of mucosal folds or secondary lumina formation in epithelial downgrowths after inflammation are also described mechanisms 6 7.

Medication-Related Cysts

Chronic use of eye drops with preservatives (such as benzalkonium chloride) has been reported to damage conjunctival epithelium, occasionally leading to cyst formation. This is more likely with prolonged or multiple-drug therapy 9.

Parasitic and Rare Causes

In rare situations, cysts can develop as a response to parasitic infection or due to unique anatomical variations 1 7.

Treatment of Conjunctival Cyst

Treatment strategies for conjunctival cysts range from simple observation to advanced surgical or laser procedures. The best approach depends on symptom severity, cyst type, size, and potential for recurrence.

Treatment	Method/Approach	Advantages/Considerations	Source(s)
Observation	Watchful waiting, no action	For small, asymptomatic cysts	11
Surgical Excision	Complete removal by surgery	Prevents recurrence if intact	1 3 12
Laser Ablation	Argon or PASCAL laser removal	Minimally invasive, outpatient	13 14
Plasma Ablation	Atmospheric low-temperature plasma	Office-based, effective	10
Cautery	Thermal cauterization	Fast, effective, low recurrence	11
Drug Modification	Discontinuation of causative drops	Prevents recurrence	9
Visualization Aids	Indocyanine green injection	Improves surgical precision	12

Table 4: Main Treatment Strategies

Observation and Conservative Management

Small, asymptomatic cysts may not require intervention. Many resolve spontaneously, especially if related to recent surgery or minor trauma 11. Observation is appropriate if the cyst is not causing discomfort or visual problems.

Surgical Excision

Surgical removal remains the gold standard for symptomatic or persistent conjunctival cysts. Complete, intact excision is critical to prevent recurrence. Minor modifications in technique—such as adjusting for cyst size, location, and structure—can enhance outcomes 1 3 12.

• Visualization techniques: Using agents like indocyanine green can help delineate cyst boundaries, ensuring complete removal 12.
• Recurrence: Careful handling to avoid rupture of the cyst wall during surgery is key to minimizing recurrence risk 1 3.

Laser and Plasma-Based Approaches

Modern, minimally invasive alternatives include laser ablation (argon or pattern scan laser) and atmospheric low-temperature plasma (ALTP):

• Laser photoablation: Effective for outpatient management, especially for small to medium cysts. Staining the cyst surface can improve laser absorption and efficacy 13 14.
• Plasma ablation: Offers a simple, office-based option with favorable outcomes and minimal complications 10.

Thermal Cautery

Cauterization under slit-lamp guidance is a quick and well-tolerated technique, particularly for inclusion cysts formed after surgery 11.

Addressing Underlying Causes

In medication-induced cysts, discontinuation or change of the offending drug may resolve the problem and prevent recurrence 9.

Conclusion

Conjunctival cysts present a diverse clinical challenge, ranging from benign, asymptomatic lesions to those causing significant discomfort or visual disturbance. Early recognition and accurate classification are essential for optimal management.

Key Takeaways:

• Symptoms: Most commonly present as swelling, foreign body sensation, and cosmetic concerns. Rarely, they cause visual impairment or eye movement restriction.
• Types: Include primary/congenital, secondary/acquired, retention, parasitic, lymphatic, dermoid/epidermoid, and those associated with pterygium.
• Causes: Origin may be congenital, traumatic, post-surgical, glandular, inflammatory, drug-induced, or (rarely) parasitic.
• Treatment: Ranges from observation to advanced surgical, laser, and plasma-based interventions. Complete removal is critical to prevent recurrence; modern minimally invasive options are increasingly available.

By understanding the spectrum of conjunctival cysts, patients and clinicians can work together to select the most appropriate, effective, and least disruptive management strategy.