Understanding Keratoconus: Causes, Symptoms, and Treatments

Keratoconus: A Comprehensive Overview

Keratoconus is an eye condition that has garnered significant attention in the medical community due to its unique characteristics and impact on vision. This progressive eye disease affects the cornea, the clear front surface of the eye, causing it to thin and bulge into a cone-like shape. This distortion leads to visual impairment and can significantly affect an individual's quality of life.

Table of Contents

• What is Keratoconus?
• Symptoms of Keratoconus
• Causes and Risk Factors
• Diagnosis and Treatment
• Correcting Keratoconus: Spectacles and Soft Contact Lenses
• Advanced Keratoconus Treatments
  • Corneal Collagen Cross-Linking (CXL)
  • Contact Lenses for Advanced Keratoconus
• Surgical Options for Keratoconus

Key Takeaways

• Keratoconus is a progressive eye disease that affects the cornea.
• It leads to visual distortion and can severely impact vision.
• The exact cause is unknown, but genetic and environmental factors play a role.
• Treatment options vary based on the severity of the condition.

What is Keratoconus?

Keratoconus, as the name suggests, is derived from the Greek words 'kerato' meaning cornea and 'conus' meaning cone. It is a condition where the cornea, which is typically round, starts to thin and bulge into a cone shape. This abnormal shape prevents light from focusing correctly on the retina, leading to distorted vision.

Symptoms of Keratoconus

The onset of keratoconus typically occurs in the late teens or early twenties. The symptoms can vary based on the progression of the disease. Common symptoms include:

• Blurred or distorted vision: This is one of the primary indicators of keratoconus.
• Increased sensitivity to light and glare: Many individuals report difficulty, especially during nighttime driving.
• Frequent changes in eyeglass prescriptions: As the cornea's shape changes, so does the prescription needed to correct vision.
• Sudden clouding or worsening of vision: This can be alarming and is a sign of advanced keratoconus.

Causes and Risk Factors

The exact cause of keratoconus remains unknown. However, it is believed that a combination of genetic and environmental factors contributes to its development. Some of the known risk factors include:

• Genetics: A family history of keratoconus increases the risk.
• Vigorous eye rubbing: Constant and vigorous rubbing of the eyes can exacerbate the condition.
• Associated conditions: Conditions like Down syndrome, Ehlers-Danlos syndrome, and asthma have been linked to keratoconus.

Diagnosis and Treatment

Diagnosing keratoconus involves a comprehensive eye examination. Advanced cases can be detected through visual inspection, but early stages might require corneal topography, which maps the curvature of the cornea.

Treatment options vary based on the severity of the condition. In the early stages, glasses or soft contact lenses might suffice. As the disease progresses, rigid gas permeable contact lenses or even corneal transplants might be necessary.

A promising treatment called corneal collagen cross-linking has shown potential in slowing or halting the progression of keratoconus. This treatment strengthens the corneal tissue, preventing it from bulging further.

Correcting Keratoconus: Spectacles and Soft Contact Lenses

While Keratoconus is a progressive eye condition that can lead to distorted vision, there are non-surgical methods available to help correct and manage its effects. Two of the primary non-surgical interventions include:

Spectacles:

• Usage: In the early stages of Keratoconus, when the corneal distortion is minimal, spectacles can be effective in correcting the refractive error caused by the condition.
• Benefits: They are non-invasive, easy to use, and can be updated as the prescription changes over time.
• Limitations: As Keratoconus progresses and the cornea becomes more irregular, spectacles might not provide optimal vision correction. They may not address all the visual distortions caused by the condition.

Soft Contact Lenses:

• Usage: Soft contact lenses can offer a more tailored fit than spectacles, conforming to the shape of the cornea and providing a clearer vision.
• Benefits: They provide a more direct correction method by sitting on the cornea, which can offer improved visual clarity compared to spectacles, especially in moderate cases of Keratoconus.
• Limitations: In more advanced stages of Keratoconus, where the corneal shape is highly irregular, standard soft lenses might not provide the best fit or vision. Specialized lenses or other interventions might be required.

Advanced Keratoconus Treatments

Keratoconus is a progressive eye condition that affects the cornea, the clear front surface of the eye. As the disease progresses, the cornea becomes thin and begins to bulge into a cone-like shape, leading to blurred vision and sensitivity to light. In the previous section, we discussed the basics of keratoconus, its symptoms, and initial treatment options. In this section, we will delve deeper into advanced treatments for keratoconus and how they can help manage the condition.

Corneal Collagen Cross-Linking (CXL)

One of the most promising treatments for halting the progression of keratoconus is corneal collagen cross-linking. This procedure involves saturating the cornea with riboflavin eye drops and then treating it with ultraviolet light. The treatment results in the cross-linking of the cornea, which stiffens the cornea and prevents further shape changes. Not only does this treatment stabilize the structure of the cornea, but it also has the potential to prevent the need for a cornea transplant in the future.

Contact Lenses for Advanced Keratoconus

As Keratoconus progresses, the cornea becomes increasingly irregular in shape, making it challenging to achieve clear vision with standard glasses or contact lenses. Specialized lenses are often required to cater to the unique shape of the cornea and provide optimal vision. Here's a detailed look at the lens options for those with advanced Keratoconus:

Hard Contact Lenses (Rigid Gas Permeable Lenses)

• Description: Rigid Gas Permeable (RGP) lenses are made of a firm, durable plastic that transmits oxygen. They retain their shape on the eye, which can help mask corneal irregularities caused by Keratoconus.
• Benefits:
  • Provides sharp vision by compensating for the irregular shape of the cornea.
  • Durable and can last longer than soft lenses.
  • Less prone to harboring bacteria compared to soft lenses.
• Drawbacks:
  • Initial discomfort, especially during the adaptation phase.
  • May dislodge easily, especially in active individuals.
• Fitting: Custom-fitted based on the eye's shape to ensure optimal vision and comfort.

Piggyback Lenses

• Description: This involves wearing two lenses on the same eye. A soft lens is placed directly on the eye, followed by an RGP lens on top.
• Benefits:
  • Provides the vision benefits of RGP lenses while offering the comfort of soft lenses.
  • Reduces the risk of corneal abrasions.
• Drawbacks:
  • Requires careful cleaning and maintenance of two lenses.
  • Increased risk of lens-related complications if not managed properly.
• Fitting: Both lenses must be carefully selected and fitted to ensure they work in harmony.

Hybrid Lenses

• Description: Hybrid contact lenses have a central rigid zone, surrounded by a peripheral soft skirt.
• Benefits:
  • Combines the sharp vision of RGP lenses with the comfort of soft lenses.
  • Suitable for those who struggle with RGP lens stability.
• Drawbacks:
  • Can be more expensive than other lens types.
  • Requires specialized fitting.
• Fitting: Custom-fitted, ensuring the rigid center aligns well with the corneal apex for optimal vision.

Scleral Lenses

• Description: These are large-diameter RGP lenses that rest on the sclera (the white part of the eye) and vault over the entire corneal surface without touching it.
• Benefits:
  • Provides excellent comfort as it doesn't touch the sensitive cornea.
  • Retains a reservoir of saline solution between the lens and the cornea, which can be soothing.
  • Ideal for those with highly irregular corneas.
• Drawbacks:
  • Requires a more involved fitting process.
  • Can be challenging to insert and remove.
• Fitting: Custom-fitted based on detailed measurements of the eye's surface. Regular follow-ups are essential to ensure continued fit and eye health.

Surgical Options for Keratoconus

Keratoconus can sometimes progress to a point where non-surgical treatments, such as contact lenses, are no longer effective or tolerable. In such cases, surgical interventions may be required to restore vision and prevent further deterioration. Here's a detailed look at the surgical options available:

Intrastromal Corneal Ring Segments (ICRS)

• Description: ICRS, also known as Intacs, are tiny, clear, semi-circular implants made of biocompatible material. They are surgically placed within the cornea's outer layer to reshape and stabilize it.
• Procedure:
  • A small incision is made in the cornea.
  • The ring segments are then inserted into the cornea, creating a flatter shape.
  • The procedure is minimally invasive and can be reversed if necessary.
• Benefits:
  • Helps reduce the irregularity of the cornea.
  • Can improve uncorrected vision and make it easier to wear contact lenses.
  • The procedure is less invasive than a corneal transplant.
• Drawbacks:
  • May not be suitable for all patients, especially those with severe keratoconus.
  • Potential for complications such as infection or ring segment migration.
• Recovery: Most patients can return to their normal activities within a few days, but it may take weeks to months for vision to stabilize fully.

Cornea Transplant (Keratoplasty)

• Description: A cornea transplant involves replacing the damaged or scarred corneal tissue with healthy donor tissue. There are two main types of corneal transplants: Penetrating Keratoplasty (PK) and Deep Anterior Lamellar Keratoplasty (DALK).
• Procedure:
  • PK: The entire thickness of the cornea is replaced.
  • DALK: Only the outer and middle layers of the cornea are replaced, preserving the innermost layer.
  • The donor tissue is sutured into place using fine stitches.
• Benefits:
  • Can significantly improve vision in cases where other treatments are ineffective.
  • DALK has a lower risk of graft rejection compared to PK.
• Drawbacks:
  • Potential for complications such as graft rejection, infection, or astigmatism.
  • Requires a longer recovery period compared to other treatments.
• Recovery: Vision may take several months to stabilize after the procedure. Regular follow-ups are essential to monitor for complications and ensure the graft is healing properly.

EMME Visioncare and Keratoconus Management

While surgical interventions can be a vital step in managing advanced Keratoconus, it's essential to understand the range of services provided by different eye care professionals. EMME Visioncare, for instance, does not offer surgical options for Keratoconus. Instead, we focus on non-surgical management of the condition.

For those living with Keratoconus, contact lenses can be a game-changer, offering improved vision and comfort. EMME Visioncare excels in this domain, providing specialized contact lens services tailored for Keratoconus patients. Their expertise ensures that patients receive the best fit, maximizing vision clarity and minimizing discomfort.

If you or a loved one is grappling with Keratoconus, it's crucial to consult with professionals like those at EMME Visioncare. They can guide you through the myriad of lens options available, helping you make an informed decision that aligns with your unique needs and lifestyle.

External Resources

For those interested in diving deeper into keratoconus and its treatments, here are some external resources:

• 9 Treatment Options for a Person with Keratoconus
• Treatment options for advanced keratoconus: A review
• Keratoconus treatments progress, aiming to eliminate need for surgery
• Mayo Clinic: Keratoconus - Symptoms and causes
• Mayo Clinic: Keratoconus Treatment Video

Relevant Videos and Resources

For a deeper understanding of keratoconus, consider watching the following videos:

• National Keratoconus Foundation: Keratoconus Resources Video
• What is Keratoconus? (Keratoconus Eye Disease Explained)
• Keratoconus (Ophthalmology) - For Medical Students

Additionally, the Mayo Clinic offers a comprehensive overview of the condition, its symptoms, causes, and treatment options. Other valuable resources include articles from Johns Hopkins Medicine and the American Academy of Ophthalmology.