Keratoconus is a weakness in the cornea that allows pressure inside the eye to distort the curve of the front of the eye. This results in increased astigmatism, reduced vision and thinning of the cornea.
It is commonly found in people with conditions that cause itchy eyes such as hay fever, eczema, and allergies. Eye rubbing is a risk factor for developing keratoconus and its progression. It is also more likely to progress in younger patients. While patients can have a genetic predisposition to the disease it is often random.
Keratoconus is not curable but often stabilises naturally by the early 30s. Glasses or rigid gas permeable contact lenses are generally the first treatment option for patients with mild keratoconus. Patients with moderate keratoconus who are at risk of worsening or who are worsening are often recommended ultraviolet corneal crosslinking. One of the safest and most effective ways to treat keratoconus, crosslinking stiffens the cornea, slowing or stopping the progression of the disease. The procedure involves applying a dye to the cornea followed by an ultraviolet laser. This creates a reaction within the cornea leading collagen fibres to “crosslink” and strengthen the cornea.
Two minimally invasive procedures used to treat keratoconus are ultraviolet corneal crosslinking and kerarings.
- Ultraviolet corneal crosslinking involves applying a dye to the cornea, followed by an ultraviolet laser. This creates a reaction that leads the collagen fibres to “crosslink” and strengthen the cornea. UV crosslinking is generally recommended if the condition is worsening or is at risk of worsening. Approximately one third of patients will experience improvement in their vision from the procedure. However, if the condition continues to progress the treatment can be repeated.
- Kerarings are clear, semicircular rings inserted within the cornea to restore it to a more normal curve and improve vision. Kerarings are generally used when the disease is moderate. The procedure is safe and minimally invasive.
Patients with advanced keratoconus may require a corneal transplant.