What Is Keratoconus

Keratoconus is a progressive eye condition that causes the cornea to thin and bulge into a cone shape, resulting in distorted vision. In a healthy eye, the cornea maintains a dome-like shape, allowing light to focus correctly on the retina. In keratoconus, structural changes cause the cornea to thin and protrude outward.

This condition often manifests during adolescence or early adulthood and can significantly impact daily activities if left untreated.

Recognizing the Symptoms of Keratoconus

Keratoconus symptoms often start in adolescence or early adulthood and progress over time. The severity and speed of progression vary from person to person.

Blurred or Distorted Vision

The irregular curvature of the cornea causes light to scatter as it enters the eye, making objects appear blurry, stretched, or wavy. Straight lines may appear bent, and fine details can be difficult to distinguish.

Increased Sensitivity to Light and Glare

Bright lights, such as headlights, streetlights, or sunlight, may cause excessive glare, halos, or discomfort, making it challenging to see clearly in well-lit environments.

Frequent Changes in Prescription

As the cornea changes shape, vision may fluctuate, requiring frequent updates to eyeglasses or contact lenses, often with diminishing effectiveness over time.

Difficulty Seeing at Night

Low-light conditions can worsen visual distortions, leading to poor night vision. Tasks like driving in the dark may become particularly difficult due to increased glare and reduced contrast sensitivity.

Sudden or Rapid Vision Loss

In advanced stages, the cornea may develop scarring or sudden swelling (hydrops), causing a significant and rapid decline in vision that may not be correctable with standard glasses or lenses.

What Causes Keratoconus?

Although the exact cause of keratoconus is unknown, several factors may play a role in its development. Identifying and managing the following risk factors may help slow or prevent keratoconus progression.

• Genetics: Having a family history of keratoconus increases the likelihood of developing the condition. Some studies suggest that genetic mutations affecting collagen production in the cornea may be responsible.
• Chronic Eye Rubbing Repeatedly rubbing the eyes, particularly in individuals with allergies or atopic conditions, has been linked to keratoconus progression.
• Connective Tissue Disorders: Conditions such as Marfan syndrome and Ehlers-Danlos syndrome, which affect collagen and structural integrity, may cause corneal thinning.
• Inflammation: Chronic eye inflammation from allergies, asthma, or other conditions may degrade corneal tissue over time.
• Oxidative Stress: Increased oxidative damage within the cornea may lead to tissue thinning and weakening.

How It Is Diagnosed

Diagnosing keratoconus requires a thorough professional eye exam and specialized tests to assess corneal shape, thickness, and irregularities. Since keratoconus often progresses slowly, regular monitoring is essential to track changes and determine the best treatment approach. Your optometrist may use the following diagnostic tools:

• Corneal Topography: This imaging technique maps the cornea’s surface, detecting any early changes in shape.
• Pachymetry: This technique allows your eye doctor to measure your corneal thickness and assess thinning patterns.
• Optical Coherence Tomography (OCT): OCT provides high-resolution cross-sectional images of the cornea, allowing for precise measurements of its thickness and structure.
• Slit-Lamp Examination: A specialized microscope helps detect subtle corneal irregularities and signs of keratoconus.
• Wavefront Aberrometry: This advanced test measures how light waves pass through the eye, revealing distortions caused by irregular astigmatism.

Treatment Options for Keratoconus

The best approach depends on the severity of the condition, with non-surgical options often effective in the early stages and surgical procedures reserved for more advanced cases.

Non-Surgical Treatments

While these treatments do not stop the disease from progressing, they can significantly enhance visual clarity and your quality of life.

Custom Eyeglasses

In the early stages, specially designed glasses or soft contacts may correct mild distortions. However, as the condition progresses, you may need stronger solutions.

Rigid Gas Permeable (RGP) Lenses 

These firm lenses provide a smooth optical surface, which improves vision by masking the cornea's irregular shape. They are a common choice for patients with moderate keratoconus.

Hybrid Lenses

Combining an RGP center for clear vision and a soft outer ring for comfort, hybrid lenses offer a balance of clarity and ease of wear.

Scleral Lenses

Scleral lenses are large contact lenses designed to rest on the sclera (white part of the eye). They don't touch your cornea, making them good for eyes with irregular shapes.  They are especially beneficial for advanced cases where other lenses may not work.

Corneal Cross-Linking (CXL)

This minimally invasive technique strengthens the cornea using riboflavin drops activated by UV light. This treatment helps strengthen corneal fibers, slowing or halting the progression of keratoconus. 

Surgical Treatments

When keratoconus progresses beyond the effectiveness of contact lenses and corneal cross-linking, these procedures reshape, reinforce, or replace the cornea to restore vision and improve corneal stability. This depends on the patient’s age, disease stage, and your overall eye health.

Intracorneal Ring Segments (Intacs)

Intacs are small, arc-shaped implants placed within the cornea to reduce irregularity and improve visual clarity. They help flatten the corneal curvature, making contact lenses more tolerable and improving unaided vision, often combined with corneal cross-linking for better long-term stability. This procedure is minimally invasive, adjustable, and reversible. 

Corneal Tissue Addition Keratoplasty (CTAK)

CTAK strengthens the cornea by integrating thin, sterilized donor tissue inlays rather than a full transplant. This technique reshapes and reinforces the existing cornea, improving its structure and visual function. This method offers faster recovery, a lower risk of rejection, and a less invasive alternative to traditional corneal transplantation.

Corneal Transplantation

A corneal transplant may be necessary in more severe cases where the cornea has become too thin or scarred for other therapies to be successful. There are two primary types of transplants:

• Penetrating Keratoplasty (PKP): This full-thickness corneal transplant replaces the entire damaged cornea with a healthy donor cornea. It can restore vision in advanced keratoconus cases but requires a longer recovery time and has a higher risk of graft rejection. Regular check-ups and medication help maintain the graft’s health.
• Deep Anterior Lamellar Keratoplasty (DALK): This partial-thickness transplant removes only the damaged outer layers of the cornea while keeping the healthy inner layer intact. Because more of the patient’s natural cornea remains, the risk of rejection is lower than with PKP. DALK offers faster recovery, better long-term stability, and significant vision improvement.

Our Comprehensive Care for Long-Term Eye Health

Our experienced specialists provide comprehensive eye exams to monitor progression and adjust treatments as needed, giving you optimal vision stability. We offer expert fittings for specialty contact lenses, including scleral and hybrid lenses, to provide you with comfort and clarity. 

Additionally, we emphasize the importance of UV protection by recommending high-quality sunglasses to safeguard your corneal health. By staying at the forefront of keratoconus research and offering cutting-edge treatments like corneal cross-linking and surgical interventions when necessary, we ensure that you receive the best possible care.

Struggling with changing vision or discomfort? Our specialists at Eyecare Associates of Texas, P.A., can help you with personalized eye care treatments to regain control of your sight. Schedule a consultation with our team to explore the best options for your unique needs today!