Keratoconus - Cause and Treatment
Keratoconus is a corneal dystrophy which causes astigmatism, and often leads to severe vision loss. The cause is not entirely known. The cornea becomes thin and irregular in shape, eventually bulging and becoming scarred. The word keratoconus actually translates to "cone-shaped cornea." Advanced keratoconus requires a corneal transplant.
Keratoconus is hereditary, but many people with the gene never develop the disorder. It is believed that something, such as a hormonal change, must trigger the thinning of the cornea. Once the process has started things like wearing poorly fitted contact lenses, excessive eye rubbing, exposure to sunlight, and chronic eye irritation, can worsen the condition.
Symptoms of keratoconus typically appear when a person is in their late teens or early twenties. In most cases both eyes are affects, but each eye may be affected differently. Symptoms can include:
- Blurred vision
- Light sensitivity
- Frequently changing corrective lens prescription
- Eye rubbing
- Munson's sign - lower lid visibly distorted due to protrusion of the cornea
In some patients the progression of keratoconus slows down or stops after 10 to 20 years. The type of treatment required depends on the severity of the condition and the associated vision loss. Initially, corrective lenses, including glasses, soft contacts, and rigid contacts can be worn to correct the astigmatism caused by keratoconus, but as the cornea becomes more distorted it can become impossible to achieve enough correction from glasses, or to create a contact lens which will fit properly. Keratoconus treatments include:
- UV crosslinking - uses ultra violet rays and riboflavin (vitamin B2) to strengthen collagen in the eye, and slow down or stop the progression
- Scleral Lens Prosthetic Device - acts like a bandage over the cornea
- Intrastromal rings - (Intacs or Ferrara rings) plastic inserts, placed inside of the eye, which help stabilize and correct irregularities in the shape of the cornea, sometimes making it possible to wear contact lenses
- Implantable lenses - avoid the problems of trying to fit traditional contact lenses and the further damage caused by poorly fitted lenses
- Deep Anterior Lamellar Keratoplasty (DALK) or Automated Lamellar Therapeutic Keratectomy (ALTK) - replaces the anterior layers of the cornea with donor tissue, without the risk of rejection associated with full corneal transplant
- Penetrating keratoplasty - about 20% of people with keratoconus eventually require a full corneal transplant
Hope for the Future
A full corneal transplant carries the risk of rejection and typically does not permanently improve vision. New treatments for keratoconus are constantly being researched, and more effective alternatives to corneal transplants are becoming available. The Global Keratoconus Foundation was created to help people with keratoconus by bringing the experts together and creating a support community where both patients and doctors can share their knowledge. They have made significant progress toward eliminating the need for full corneal transplants, and are now working to eliminate keratoconus as a health issue. Early treatment and less invasive treatment methods can greatly improve the outcome of keratoconus and the likelihood of retaining good vision.
If you are experiencing the symptoms of keratoconus, talk to an experienced ophthalmologist today. Visit The Global Keratoconus Foundation to learn more about the condition and the advancements in treatment being made every day.