Keratoconus is a progressive eye disease in which the normally round, dome-shaped cornea (the front surface of the eye) thins and bulges into a cone-like shape. This irregular shape distorts the cornea’s ability to focus light properly on the retina, leading to blurred or distorted vision. It typically affects both eyes but can progress differently in each.
Key Features of Keratoconus:
1. Causes:
- The exact cause is unknown, but it may be linked to a combination of genetic, environmental, and cellular factors.
- It may run in families, and people with certain conditions like Down syndrome, asthma, or hay fever have a higher risk.
- Vigorous eye rubbing or chronic eye irritation can also be associated with its development.
2. Symptoms:
- Blurry vision
- Sensitivity to light and glare
- Frequent changes in eyeglass prescription
- Distorted or double vision
- Difficulty seeing at night
3. Progression:
- Keratoconus often begins in adolescence or early adulthood and progresses for about 10-20 years. The progression may slow down as a person gets older.
- As it advances, the cornea becomes thinner and more irregular, leading to worsening vision that cannot be fully corrected with glasses.
4. Diagnosis:
- A comprehensive eye exam, including corneal topography, is used to map the shape of the cornea.
- Corneal pachymetry measures the thickness of the cornea.
- Keratometry or slit-lamp examination can help assess the curvature of the cornea.
5. Treatment:
- Glasses or Soft Contact Lenses: In the early stages, glasses or soft contact lenses can help correct vision.
- Rigid Gas Permeable (RGP) Lenses: As the condition progresses, RGP lenses can offer better vision by creating a smooth refractive surface over the irregular cornea.
- Scleral Lenses: These larger lenses rest on the sclera (the white part of the eye) and vault over the cornea, providing clear vision.
- Corneal Cross-Linking (CXL): This is a procedure designed to strengthen the corneal tissue and halt progression by using ultraviolet light and a riboflavin solution.
- Intacs: These are small, semi-circular rings implanted in the cornea to flatten it and improve vision.
- Corneal Transplant: In advanced cases where other treatments fail, a corneal transplant may be required to restore vision.
Keratoconus can lead to significant vision impairment if not properly managed, but with advancements in treatments like cross-linking, many people can stabilize the condition and improve their quality of life.