Pellucid Marginal Degeneration: What It Is and How It Is Treated

Written by Medicover Team and Medically Reviewed by Dr Vompolu Kamakshi Bhaskar , Ophthalmologists

Causes
Find a Doctor
Diagnosis
Treatment
FAQs
Book an Appointment

1. Causes 2. Find a Doctor 3. Diagnosis 4. Treatment 5. FAQs

Pellucid Marginal Degeneration (PMD) is a relatively rare, non-inflammatory corneal condition that can progressively affect vision.

PMD causes thinning of the lower peripheral cornea, which can alter the shape of the cornea and lead to irregular astigmatism and visual disturbances. Understanding its causes, risk factors, symptoms, diagnosis, and treatment options can help in managing the condition and preserving vision.

What Are the Causes of Pellucid Marginal Degeneration?

Pellucid Marginal Degeneration (PMD) is a rare, non-inflammatory corneal disorder characterized by thinning of the inferior peripheral cornea. The exact cause of PMD is not fully understood, but it is believed to result from a combination of genetic susceptibility and factors that affect corneal structure and integrity.

Abnormalities in collagen structure or corneal biomechanics may contribute to progressive thinning and distortion of the cornea. Although PMD is not typically associated with systemic diseases, certain factors may worsen its progression.

Genetic predisposition: A hereditary component is suspected, as PMD may occur more frequently in individuals with a family history of corneal disorders.
Corneal structural weakness: Alterations in collagen fibers and corneal tissue strength may contribute to progressive thinning.
Chronic eye rubbing: Repeated mechanical stress on the cornea may accelerate thinning or worsen corneal irregularity.
Environmental and allergic factors: Long-term eye irritation or allergic eye disease may contribute to eye rubbing and disease progression.

What Are the Symptoms of Pellucid Marginal Degeneration?

The symptoms of Pellucid Marginal Degeneration often develop gradually. As the cornea becomes thinner and more irregular, visual disturbances may become increasingly noticeable and interfere with daily activities.

Blurred or distorted vision: Blurred vision may occur because of the irregular shape of the cornea.
Irregular astigmatism: Changes in corneal curvature can make it difficult to focus clearly and may cause double or ghost images.
Light sensitivity: Increased sensitivity to bright light and glare may occur.
Difficulty with night vision: Reduced visual clarity in low-light conditions may make activities such as night driving difficult.
Frequent prescription changes: Changing corneal curvature may result in the need for repeated changes to glasses or contact lens prescriptions.

How Does Pellucid Marginal Degeneration Affect Vision?

Visual disturbances in PMD primarily result from irregular astigmatism caused by corneal thinning. As the lower portion of the cornea becomes thinner, its normal curvature changes and affects how light is focused onto the retina.

This can result in blurred, distorted, or doubled images that may not be fully corrected with standard eyeglasses. Over time, these changes can interfere with reading, driving, and other daily activities.

When Should You See a Doctor for Pellucid Marginal Degeneration?

Consult an eye specialist if you notice changes in vision or symptoms that affect your daily visual function.

Progressive blurred or distorted vision
Increasing difficulty seeing at night or in low-light conditions
Sensitivity to light or glare affecting normal activities

Get medical help immediately if:

Sudden and severe worsening of vision
Eye pain or significant discomfort associated with vision changes
Sudden inability to see clearly even with corrective lenses

Early evaluation can help monitor Pellucid Marginal Degeneration and guide appropriate treatment to preserve vision.

Find Ophthalmologists for Pellucid Marginal Degeneration Treatment Near You

How Is Pellucid Marginal Degeneration Diagnosed?

Diagnosing Pellucid Marginal Degeneration requires a detailed eye examination and corneal imaging. Early diagnosis helps monitor progression and distinguish PMD from other corneal ectatic disorders, such as keratoconus.

An optometrist or ophthalmologist may assess visual acuity, refractive errors, and the shape and thickness of the cornea.

Corneal topography: Maps the curvature of the cornea and can show characteristic patterns associated with PMD.
Pachymetry: Measures corneal thickness and helps identify localized thinning, particularly in the lower peripheral cornea.
Slit-lamp examination: Allows detailed examination of the cornea for thinning, structural irregularities, and other abnormalities.
Corneal tomography: Advanced imaging, such as Scheimpflug imaging, provides detailed information about the anterior and posterior corneal surfaces.
Refraction test: Determines the degree of astigmatism and the extent of visual impairment.

Accurate diagnosis helps differentiate PMD from similar corneal conditions and guides appropriate treatment planning.

What Are the Treatment Options for Pellucid Marginal Degeneration?

There is no definitive cure for Pellucid Marginal Degeneration, but treatment can improve vision and, in selected cases, help stabilize progressive corneal thinning. The choice of treatment depends on the severity of corneal changes, progression, and degree of visual impairment.

What Are the Conservative Treatment Options?

In early or mild cases, corrective lenses may improve vision. Glasses or soft contact lenses may help when corneal irregularity is limited, although they may become less effective as the condition progresses.

Which Contact Lenses Are Used for PMD?

Specialized contact lenses may provide better vision correction when glasses are no longer adequate.

Rigid gas-permeable (RGP) lenses: Provide a smooth optical surface over the irregular cornea to improve visual clarity.
Scleral lenses: Rest on the white part of the eye and vault over the cornea, providing a stable optical surface and improved comfort for many patients.
Hybrid lenses: Combine a rigid central portion with a soft outer portion to provide visual correction with added comfort.

What Surgical Treatments Are Available for PMD?

Surgical or procedural treatment may be considered for progressive or advanced disease when vision cannot be adequately corrected with contact lenses.

Corneal Cross-Linking (CXL): Strengthens corneal collagen and may help slow or stabilize progressive corneal thinning in appropriately selected patients.
Intracorneal Ring Segments (ICRS): Small implants placed within the cornea may help regularize corneal shape and reduce irregular astigmatism in selected cases.
Corneal transplantation: In severe cases involving substantial corneal thinning, scarring, or significant vision loss, partial- or full-thickness corneal transplantation may be considered.

Regular follow-up with an eye care specialist is important to monitor corneal changes, assess vision, and adjust treatment as needed.

Your health is everything - prioritize your well-being today.

Consult Pellucid Marginal Degeneration Doctors Today

What Are the Risk Factors for Pellucid Marginal Degeneration?

Several factors may be associated with PMD. Identifying these factors can help with early detection and appropriate monitoring to reduce the risk of progressive vision changes.

Age: PMD is commonly diagnosed in adults, although it can occur at other ages.
Family history: Individuals with a family history of corneal ectatic disorders may have an increased risk.
Eye rubbing: Frequent or forceful eye rubbing may contribute to corneal weakening and progression.
Allergic eye disease: Eye allergies may increase rubbing and mechanical stress on the cornea.
Corneal ectatic disorders: A history of related corneal conditions may be associated with an increased risk.