Best doctor for Laser vision correction for keratoconus
Best doctor for Laser vision correction for keratoconus
The Athen’s protocol
Keratoconus is an idiopathic condition that affects the cornea, causing it to lose its natural curvature and take on a conical shape. This results in light being scattered across the retina, leading to visual disturbances.
What is Keratoconus?
The cornea of the eye is the transparent outer surface, which normally has a certain degree of curvature. In some cases, this curvature becomes more pronounced than usual, causing the cornea to change from its natural dome-like shape to a more cone-shaped or funnel-like form. As the curvature increases, the cornea’s thickness also decreases.
This process happens gradually, meaning the shape of the cornea doesn’t change suddenly from a dome to a cone, but rather evolves slowly over several years. This condition is known as Keratoconus, and it is often believed to be hereditary in most cases.
How does this affect vision? How does a patient with keratoconus see?
Due to the change in the shape and curvature of the cornea, the cornea’s function is negatively affected. It no longer focuses light on the retina as efficiently as it should, which leads to blurred vision and changes in refractive error as the conical distortion increases.
Additionally, the conical shape of the cornea can cause localized blurring in certain spots or areas of the image formed. This happens because the cornea’s surface becomes irregular and uneven, rather than smooth and uniform, leading to distorted vision, especially for tasks like reading or seeing clearly at a distance.
What is the cause of keratoconus?
There are several factors attributed to the development of keratoconus, with the most important being genetic predisposition, as previously mentioned, and eye allergies, particularly when there is excessive rubbing of the eyes (such as in spring catarrh).
The conical distortion occurs as a result of the weakening of the connective tissue in the cornea, which leads to a decrease in the corneal thickness and increased flexibility, causing the cornea to bulge out or develop a conical shape.
When does keratoconus begin?
The exact moment when the conical distortion begins cannot be pinpointed with absolute accuracy, as it varies from case to case. However, it is generally observed that the condition can be detected starting from adolescence. Over time, it becomes more noticeable, especially as symptoms begin to appear.
Is keratoconus a genetic disease?
It is difficult to pinpoint a specific cause for keratoconus, so it cannot be definitively stated that it is a purely genetic condition. However, there are several factors that increase the likelihood of developing keratoconus, with genetics being one of the most significant factors.
That said, it would be incorrect to consider genetics as the sole or direct cause. Keratoconus can sometimes also occur as a secondary condition associated with other diseases, such as seasonal allergic conjunctivitis (spring catarrh), where constant and intense rubbing of the eyes weakens the cornea, thereby increasing the risk of developing keratoconus.in addition disease like Down syndrome and Marfan syndrome are associated with a higher risk for KC.
How is keratoconus diagnosed?
Keratoconus cannot be detected or diagnosed with the naked eye or through conventional tests. The condition is diagnosed after conducting a specialized, advanced test called corneal topography using a Pentacam machine, which provides detailed mapping of the cornea’s surface. Additionally, the presence of certain visual symptoms, such as blurred or distorted vision, may help in diagnosing the disease and confirming its presence.
What are the treatment options for keratoconus?
Keratoconus develops gradually, and therefore, treatment varies depending on the stage of the disease. Below are some treatment methods based on the progression of the condition:
Rigid Contact Lenses (Early Stages):
In the early stages of keratoconus, rigid contact lenses were commonly used to support and reshape the corneal surface to improve vision while worn. However, rigid lenses are a temporary solution, as they prevent the progression of the disease, so continuous monitoring is required.
Corneal Cross-Linking (CXL):
Corneal cross-linking is one of the primary treatments to stop the progression of keratoconus and increase the cornea’s strength. This procedure involves applying vitamin B2 (riboflavin) to the cornea and exposing it to ultraviolet light. This reaction increases the stiffness of the cornea and halts the conical shape distortion.
Ring Segments Insertion (Femto-Laser):
Ring segment insertion is used to modify the corneal shape and improve vision. Small semi circular ring-like supports are inserted into tunnels in the cornea using femtosecond laser technology, creating precise openings for the rings. This is often combined with corneal cross-linking either before, after, or during the ring implantation.
Corneal Cross-Linking with Surface Laser (Athens Protocol):
In this procedure, corneal cross-linking is combined with the removal of the corneal epithelium using PRK (Photorefractive Keratectomy) technology. Known as the Athens Protocol, this method halts the disease’s progression and improves vision in some cases, based on corneal topography results.
Corneal Transplant (Full or Partial):
In advanced cases where rigid contact lenses or cross-linking procedures do not yield results, a corneal transplant may be necessary. Lamellar Corneal transplant surgeries in Egypt have become highly successful due to the availability of femtosecond laser technology. This method allows for precise corneal grafting, reducing the rejection rates to less than 5% with a success rate of 95%. Femtolaser technology also enables more precise corneal cuts for transplant, further improving outcomes.
Each of these methods has its specific indications depending on the stage and severity of keratoconus, and they can be used alone or in combination.
Can vision be corrected in keratoconus patients?
Yes, it is possible to correct visual errors caused by keratoconus using rigid contact lenses, implantable lenses, or other methods. However, the most important aspect of treatment is to stop the progression and prevent further conical distortion of the cornea. This can be achieved by stabilizing and strengthening the cornea through:
- Ultraviolet Cross-Linking for corneal strengthening.
- Corneal Cross-Linking with Femto-Laser Ring Insertion.
- Corneal Cross-Linking with Surface Laser (Athens Protocol).
- Refractive Lens Implants either after cross-linking or combined with ring insertion.
Can LASIK be performed in keratoconus patients?
Usually, the excessive curvature of the cornea is accompanied by thinning, making it unsuitable for LASIK surgery. However, in some rare cases, the Athens Protocol, which involves surface laser treatment combined with cross-linking, can be performed if the corneal thickness allows for the removal of 50 microns of tissue.
Refractive lens implants to correct vision are typically the preferred choice for keratoconus patients after confirming corneal stability.
Dr. Ashraf Hassan Soliman, a consultant in corneal surgery, cataracts, glaucoma, and laser vision correction, is one of the top ophthalmologists in Egypt and the Arab world, specializing in keratoconus treatment and all types of corneal transplants.
