Keratoconus

Keratoconus is an eye condition in which the normal structure of the cornea progressively thins, forming a cone-shaped cornea. This alters the quality of vision and gradually reduces visual acuity. The condition usually affects both eyes.

This disorder most often appears in the mid-second decade of life. Its initial onset may go unnoticed by the patient or the ophthalmologist. The first sign is the continual, frequent change in the patient’s eyeglass prescription, primarily due to increasing astigmatism. In advanced stages, vision can be significantly reduced.

Keratoconus is a rare corneal disorder. It occurs in approximately 1 in 2,000 people, with no geographic predilection. The exact causes of keratoconus remain unknown. However, research indicates that a family history is the most significant risk factor (heredity).

Other studies suggest a correlation between the progression of the disease and conditions that cause itching (allergies or atopic disorders), particularly during childhood.

The main symptoms of the disease are:

Diagnosis is made by the clinical ophthalmologist through corneal topography examination. In this test, a computer is used to analyze the structure of the cornea and generate a map of its anterior and posterior surfaces.

The treatment of keratoconus has two main objectives:

• Stabilization of progression
  
  • Corneal cross-linking (CXL): Using vitamin B12 in combination with a source of ultraviolet light, the collagen fibers of the cornea are cross-linked, resulting in corneal strengthening and halting the progression of the disease in most cases. This is a quick procedure that does not require hospital admission and lasts about 40 minutes.

• Improvement of vision
  
  • Contact lenses (rigid lenses): Contact lenses correct a significant part of the refractive error by reshaping the cornea. However, many patients experience intolerance to these lenses, requiring alternative solutions.

• Combination of cross-linking and PRK laser (corneal laser): Not suitable for all patients. This approach can improve myopia and astigmatism significantly while stabilizing the keratoconic cornea through corneal collagen cross-linking.

• Penetrating keratoplasty or full-thickness corneal transplantation: When the cornea has become excessively thin and contact lenses or cross-linking are not viable, or when there is a high risk of perforation, this procedure is indicated. During surgery, the entire thickness of the affected cornea is replaced with a healthy graft.