Keratoconus is a disease that causes the cornea (the clear, outer layer of the eye) to thin and take on a cone shape. This degenerative eye disease affects only 1 in 2,000 people in the United States, but it can cause significant vision impairment.
Currently there are four treatment options for keratoconus:
- Glasses or contact lenses (in the early stages)
- Cross-linking treatment, which strengthens the collagen fibers of the cornea
- Deep Anterior Lamellar Keratoplasty, or DALK, which involves implantation of the front and middle layers of the cornea
- Full corneal transplant
Corneal transplants can be effective when all other treatment methods have been attempted, but they carry risk. Complications include wound healing difficulties and persistent astigmatism, which causes distorted vision.
A new procedure could improve outcomes for patients with keratoconus. At the 120th annual meeting of the American Academy of Ophthalmology, results from a five-year study suggested that transplantation of one layer of the cornea could avoid or delay full corneal transplant. Furthermore, this treatment might allow patients with advanced keratoconus to tolerate contact lens wear, which previously was difficult.
A group of researchers in the Netherlands transplanted only the second layer of the cornea called the Bowman layer. After using this treatment on 19 patients and following their progress for five years, the researchers agreed that this method improved vision and stabilized the disease in 90 percent of the eyes.
“Bowman layer transplantation may be safer than a full corneal transplant, is effective and the benefits last,” said Jack Parker, M.D., lead author of the study and a corneal fellow at the Netherlands Institute for Innovative Ocular Surgery. “The procedure can spare young people with the condition a lifetime of difficult, expensive and risky eye procedures and interventions.”
The researchers noted that the limitations of the study were that it was a small study and there was no control group. They stated that transplantation of the Bowman layer of the cornea should be studied in a larger group for more conclusive results (Source: American Association for the Advancement of Science).