What is Keratoconus?
Cornea is the transparent anterior portion of the eye covering the iris, the anterior chamber and the pupil. Normally, cornea is responsible for refraction of light. But when it bulges abnormally due to progressive thinning in the middle, the cornea assumes the shape of a cone leading to a condition called keratoconus. It is a non-inflammatory condition in which the amount of light entering into the eye gets deflected on its way to the retina.
Signs and Symptoms of Keratoconus
Typically, keratoconus can develop during puberty and progress till mid thirties. After this, its progression generally slows and arrests on its own. The condition can affect one eye or both the eyes. As the condition progresses, it may show multiple signs and symptoms depending on its severity.
Some of the common symptoms of keratoconus are as under:
- Cone shaped and irregular (surface) cornea
- Distorted vision with multiple images
- Recurrent sensation of foreign body
- Nearsightedness
- Sensitivity to light
Keratoconus Causes
The actual cause of keratoconus is still not known. One theory believes that it can result from free radical damage leading to collagen loss and bulging of cornea. Others believe that keratoconus may result from rubbing of eyes. The condition is also linked with exposure to ultraviolet ray, chronic eye irritation and also ill fit contact lenses.
Treatment of Keratoconus
Initially, wearing soft contact lenses or eye glasses may correct the vision. But as keratoconus progresses, soft contact lenses or eye glasses can no longer provide any significant help.
In that case, rigid gas permeable (RGP) contact lenses are considered as preferred treatment. But fitting RGP contact lenses on keratoconus eyes (having irregular corneal surface) can be challenging and time consuming. For this reason, practitioners sometimes recommend piggybacking contact lenses (i.e. fitting RGP contact lenses over soft contact lens). But when therapies or contact lenses fails to bring any significant difference to vision, as a last recourse, corneal transplant is considered.
