Corneal Dermoid: Overview of Types, Surgical Care, and More

Corneal dermoids are rare, benign growths composed of skin-like tissue that develop in or around the cornea. Typically present at birth, their size and location vary, potentially affecting vision and eye function. While some cause minimal disruption, others require medical intervention to prevent complications such as astigmatism or irritation.

Management depends on severity, symptoms, and impact on vision. Treatment ranges from monitoring mild cases to surgical removal for more significant growths.

Physical Characteristics

Corneal dermoids appear as well-defined, elevated lesions containing hair follicles, sebaceous glands, and connective tissue. Their color ranges from pale yellow to light brown, often with visible hair that can cause mechanical irritation. Texture varies, with some appearing smooth and others rough due to embedded structures. These firm lesions reflect their dense fibrous and epithelial composition.

Size differs significantly, from small nodules to larger masses that obscure vision. Smaller dermoids may remain at the limbus or peripheral cornea, while larger ones extend deeper into the stroma, affecting transparency and refractive properties. Some protrude outward, altering corneal curvature and causing astigmatism. Vascularization varies, with some lesions exhibiting prominent blood vessels that contribute to irritation.

Location influences ocular function. Lesions near the visual axis interfere with light transmission, leading to blurred vision or amblyopia in children. Those at the limbus can disrupt the tear film, causing dryness or discomfort. Hair on the lesion exacerbates symptoms, as friction against the cornea leads to chronic irritation, redness, and foreign body sensation. Over time, mechanical disruption may cause corneal abrasions or localized inflammation.

Types Of Corneal Dermoids

Corneal dermoids are classified by location: limbal, corneal, or epibulbar. Each type has distinct clinical implications, influencing management decisions.

Limbal

Limbal dermoids, the most common type, develop at the junction of the cornea and sclera. These raised, well-circumscribed masses have a yellowish or whitish hue and may contain hair or glandular tissue. While peripheral placement often spares vision, larger lesions can induce astigmatism by altering corneal curvature.

Histologically, limbal dermoids contain keratinized epithelium, sebaceous glands, and collagenous stroma. Some exhibit vascularization, contributing to irritation or localized inflammation. Although small dermoids may remain stable, larger ones encroach on the cornea, sometimes requiring surgical removal to prevent visual impairment.

These dermoids are frequently associated with Goldenhar syndrome, a congenital disorder affecting craniofacial development. In such cases, they may be bilateral and accompanied by other ocular or systemic anomalies. Management depends on lesion size and symptoms, with mild cases monitored and larger growths excised for improved comfort and vision.

Corneal

Less common but more visually significant, corneal dermoids are round or oval lesions with a firm, elevated surface that may contain hair follicles or sebaceous elements. Their presence disrupts corneal transparency, leading to distortion, glare, or amblyopia in children.

Unlike limbal dermoids, corneal dermoids often extend deeper into the stroma, affecting structural integrity. Severe cases may involve Descemet’s membrane or the anterior chamber, complicating surgical removal. Vascularization varies, with some lesions exhibiting feeder vessels that contribute to irritation and neovascularization.

Management depends on size and visual impact. Small, superficial lesions may be monitored, while larger growths often require surgical excision. Lamellar or penetrating keratoplasty may restore corneal clarity and improve refractive outcomes. Early intervention is crucial in pediatric cases to prevent amblyopia.

Epibulbar

Epibulbar dermoids, located on the conjunctival surface, may extend toward the cornea or sclera. More mobile than limbal or corneal dermoids, they appear as soft, well-demarcated masses with a smooth or slightly irregular surface, containing hair, sebaceous glands, and connective tissue.

Although typically benign and asymptomatic, larger lesions can cause mechanical irritation, leading to conjunctival redness, foreign body sensation, or tear film disruption. Some are associated with systemic conditions such as Goldenhar syndrome.

Surgical removal is considered for lesions causing discomfort or cosmetic concerns. The procedure involves excision while preserving surrounding ocular structures. Unlike corneal dermoids, which may require grafting, epibulbar dermoid removal is usually straightforward, with minimal impact on vision. Postoperative care focuses on inflammation control and proper healing.

Diagnostic Approaches

Diagnosis begins with a clinical examination, as corneal dermoids are identifiable by their distinct appearance. Slit-lamp biomicroscopy assesses size, texture, vascularization, and depth of corneal involvement, differentiating dermoids from other ocular growths like conjunctival nevi or dermolipomas.

For deeper stromal involvement, anterior segment optical coherence tomography (AS-OCT) provides high-resolution cross-sectional imaging, distinguishing superficial lesions from those extending into the stroma or anterior chamber. This aids surgical planning and monitoring in pediatric cases at risk for amblyopia.

Ultrasound biomicroscopy (UBM) further evaluates larger or atypical dermoids by creating detailed images of anterior ocular structures. This technique is particularly useful for lesions with dense fibrous components or suspected intraocular extension.

In syndromic cases, systemic evaluation may be necessary. Genetic counseling and imaging, such as orbital MRI or craniofacial CT scans, help identify conditions like Goldenhar syndrome, which involves ocular, auricular, and vertebral abnormalities. Early recognition ensures coordinated care among specialists.

Surgical Techniques

Surgical removal is considered when a dermoid affects vision, causes chronic irritation, or presents cosmetic concerns. Technique selection depends on lesion size, depth, and proximity to visual structures.

Superficial excision suffices for smaller limbal dermoids that do not penetrate deeply. Using a surgical microscope, the ophthalmologist removes the lesion while preserving healthy corneal tissue to minimize scarring and postoperative astigmatism.

For deeper stromal involvement, lamellar keratectomy removes affected layers while preserving deeper structures. In more advanced cases, a partial-thickness corneal graft may be required to restore transparency. Studies suggest anterior lamellar keratoplasty yields favorable visual outcomes with lower graft rejection risk than full-thickness grafting.

Larger or invasive dermoids may necessitate penetrating keratoplasty, replacing affected corneal tissue with a donor graft. While this can improve vision, it carries higher risks of postoperative complications such as graft failure or irregular astigmatism. Corneal topography helps assess lesion impact on curvature, guiding surgical planning.

Conservative Measures

Not all corneal dermoids require surgery. Small, asymptomatic, or non-vision-threatening lesions may be managed conservatively with regular monitoring.

For mild irritation or dryness, lubricating eye drops or ointments help maintain hydration and reduce discomfort. Preservative-free artificial tears are often recommended for sensitive eyes.

If a dermoid induces mild astigmatism, corrective lenses can optimize vision without surgery. Pediatric patients require periodic refraction assessments to monitor for amblyopia or refractive changes. Hair growth on the lesion may be trimmed by an ophthalmologist to alleviate irritation. Long-term follow-up ensures stability and detects complications requiring intervention.

Postoperative Care

After surgical removal, postoperative management focuses on healing, inflammation control, and minimizing scarring or infection. Patients receive topical antibiotics to prevent infection and corticosteroid eye drops to reduce inflammation and limit corneal haze. Medication dosage and duration depend on surgical extent and individual healing response.

Follow-up visits monitor epithelial healing and corneal clarity. In cases requiring grafting, bandage contact lenses may protect the surgical site and aid recovery. Patients are advised to avoid eye rubbing, excessive sun exposure, and activities that could introduce foreign particles. If irregular astigmatism develops, rigid gas-permeable contact lenses or further refractive procedures may be considered to enhance visual outcomes.