Keratoconus is an eye condition that causes a distortion in the curve of the cornea that can result in distortion of vision and sensitivity to light. In some cases, the problem may be so severe that the person affected by this condition has difficulty driving safely or reading. This condition typically begins in adolescence and has a variety of possible causes.
The condition is caused by an imbalance of enzymes in the cornea that result in damaging chemicals being introduced to the cornea. These are known as “reactive species” chemicals and can include hydrogen peroxide, nitric oxide and superoxides. These reactive species chemicals cause oxidative damage to the cornea, resulting in keratoconus.
The condition is also associated with some factors such as:
- Frequent vigorous rubbing of the eyes.
- Long term contact lens use
- Eye conditions such as retinitis pigmentosa, retinopathy of prematurity or vernal keratoconjunctivitis
- Down syndrome
Keratoconus affects between one in every 500 to one in every 2,000 people. People of South Asian descent are at higher risk of developing this condition than the general population. People with conditions such as Leber's congenital amaurosis, Ehlers-Danlos syndrome or osteogenesis imperfect may also be at elevated risk of developing the condition.
People with the condition may only notice a slight impairment of their vision at first. Over time, this impairment can become more pronounced. The most recognizable symptom of the condition is the perception of multiple ghost images of something they are looking at, similar to double-vision. This symptom most frequently occurs when the person affected by the condition is looking at a point of light on a dark background.
Doctors have several methods they can use to test for keratoconus, including keratotomy, corneal mapping, slit-lamp testing and eye refraction. If you're diagnosed with the condition, there are several options for treating it. Eye glasses and contact lenses are the most common treatment for the disorder, with contacts being highly effective for the majority of patients. These treatments can often halt the progression of the disorder, but if it continues surgery may be necessary to correct the curvature of the cornea.
Keratoconus surgery options include special inserts that will correct the shape of the cornea or a corneal transplant. A new non-surgical treatment known as collagen cross-linking has also been developed. In the new treatment, riboflavin drops are applied to the eye and the cornea is then exposed to ultra-violet light. The result is a strengthened cornea. Cornea collagen crosslinking (Holcomb C3-R) has shown considerable success with stabilizing keratoconus. This treatment often considered early in diagnosis to prevent progressive changes to the cornea and preserve good vision in glasses or contacts.
By understanding keratoconus, its symptoms and possible causes, the general public can ensure earlier diagnosis and treatment of the condition, which will improve quality of life for those impacted by it.