Staphyloma is an eye condition in which the outer coat of the eye becomes thinned and stretched, causing it to bulge outward. This outpouching can involve the sclera or the cornea and may lead to progressive vision problems if not monitored. While some forms remain stable, others are linked to serious underlying eye diseases and require long-term care.
Understanding Staphyloma: Definition and Overview
To understand what a staphyloma is, it helps to know how the eye is structured. The sclera and cornea form the strong outer wall of the eye. When this wall weakens, it may thin and bulge outward, exposing darker underlying tissue.
The staphyloma is an abnormal protrusion of the eye wall caused by thinning. The meaning of staphyloma comes from the Greek word staphylē, meaning a cluster of grapes, which reflects its bulging appearance. In simple terms, staphyloma refers to a structural weakness of the eye that alters its normal shape.
Where Staphyloma Occurs in the Eye
A staphyloma of the eye can develop in different regions. It may appear in the front of the eye as an anterior staphyloma or in the back as a posterior staphyloma. These changes may be present at birth or develop later due to disease, injury, or degeneration.
Types of Staphyloma: Classifying the Condition
The staphyloma types are classified by location:
- Anterior Staphyloma: This involves the cornea or adjacent sclera and is often visible externally.
- Intercalary Staphyloma: This forms near the limbus, between the cornea and sclera.
- Ciliary Staphyloma: It affects the sclera over the ciliary body.
- Equatorial Staphyloma: It occurs around the equator of the eye.
- Posterior Staphyloma: This develops at the back of the eye and is commonly associated with pathologic myopia.
- Peripapillary Staphyloma: This surrounds the optic disc.
In advanced classification, staphylomas are also grouped as primary or compound, depending on the extent and combination of ocular structures involved.
What Causes Staphyloma? Major Risk Factors
The most common cause of staphyloma is pathologic myopia. About 3% of the people in the world have pathologic myopia, and 50% of those with the condition have staphyloma.
Other recognised causes include:
- Eye injuries from sharp objects or blunt trauma
- Severe infections such as keratitis or inflammation following childhood viral illnesses
- Congenital disorders, including retinitis pigmentosa and Alport’s syndrome
- Long-standing high intraocular pressure, malnutrition, or chronic ocular inflammation
- Rarely, surgical weakening of the sclera
Posterior staphyloma is most commonly associated with pathologic myopia, whereas anterior staphyloma typically develops following ocular trauma or severe eye infections.
Associated Conditions and Risk Populations
Almost half of the people with pathologic myopia develop staphyloma. Staphyloma is also associated with complications such as choroidal neovascularisation, retinoschisis, and glaucoma, all of which can threaten vision if untreated.
Signs and Symptoms of Staphyloma
Symptoms differ by type, as posterior staphylomas usually affect visual quality and may cause distortion. On the other hand, anterior staphylomas are often visible externally and can lead to abnormal pupil shape. Many patients notice a gradual worsening of vision, especially those with high myopia.
Other signs include:
- Distorted or blurred vision
- Enlargement or protrusion of the eye
- A bluish or dark appearance of the sclera
Diagnosis: How Eye Specialists Identify Staphyloma
Staphyloma diagnosis begins with a detailed eye examination, including dilated fundus evaluation. Because some forms are subtle, imaging is often required. Common diagnostic tools include:
- Optical coherence tomography to assess retinal curvature and depth
- B-scan ultrasonography for structural evaluation
- CT or MRI scans in complex or posterior cases
These tests help differentiate staphyloma from conditions such as tilted disc syndrome or peripapillary atrophy.
Treatment Options for Staphyloma: When and How to Intervene
There is no single standard staphyloma treatment. Many cases remain stable and only require regular monitoring. When progression threatens vision, treatment options may include:
- Posterior scleral reinforcement, where a graft supports the back of the eye to slow myopic progression
- Scleral or corneal patch grafts for anterior staphyloma to strengthen weakened tissue
- Newer approaches, such as collagen crosslinking combined with scleral reinforcement in selected cases
Managing Posterior Staphyloma
Posterior staphyloma management focuses on controlling high myopia, reducing near-work strain, and maintaining close follow-up. Severe or progressive cases may benefit from posterior scleral reinforcement or crosslinking.
Managing Anterior Staphyloma
Anterior staphyloma treatment related to trauma or infection often requires surgical repair with a scleral patch graft. Early intervention improves both structural stability and visual outcome.
Potential Complications and Eye Health Risks
Untreated staphyloma can lead to serious complications, including:
- Progressive vision distortion
- Increased risk of retinal detachment
- Macular degeneration
- Choroidal neovascularisation
- Glaucoma and retinoschisis
These changes are especially concerning in individuals with a high risk of pathologic myopia, where structural weakness of the eye is more pronounced. Posterior staphyloma, in particular, reflects more advanced disease and, if left untreated, may lead to irreversible vision impairment.
Living with Staphyloma: Monitoring and Prevention
Long-term care focuses on staphyloma monitoring. People with high myopia should have regular eye examinations to detect changes early.
Preventive steps to slow staphyloma progression include protecting the eyes from injury, treating infections promptly, managing refractive errors correctly, following eye health tips, and maintaining good nutrition and UV protection. Any sudden visual changes or visible eye deformities should prompt immediate medical evaluation.
Conclusion: Key Takeaways on Staphyloma and Eye Health
Staphyloma is characterised by thinning and outward bulging of the sclera or cornea and may develop in different regions of the eye. Pathologic myopia is the most common cause, although trauma, infections and congenital conditions also play a role.
Many cases remain stable with regular monitoring, but progressive disease may require surgical reinforcement. Routine eye examinations and timely evaluation of vision changes are essential to protect long-term eye health and reduce the risk of permanent visual impairment.
