Keratoconus is a condition that results from an irregularly shaped cornea, which prevents light from focusing correctly on the retina. In keratoconus, the normally round cornea becomes thin and more cone-shaped, causing blurred vision and sensitivity to bright lights.
What Causes Keratoconus?
There is no known cause for keratoconus, although experts have theorized many causes, including preexisting medical conditions, heredity, allergies, and eye rubbing. It is a gradual, slow moving disease, which typically starts in the late teens to early twenties and may continue for several years.
Symptoms of Keratoconus
In the early stages, keratoconus causes slightly blurred vision, frequent changes in eye glass prescription, and increased sensitivity to bright lights. As it progresses (over 10 to 20 years), vision may become more and more distorted.
An eye care professional can determine the presence of keratoconus using a slit lamp evaluation or by examining the surface of the cornea through corneal topography. Symptoms of keratoconus include:
Distorted vision at all distances
“Ghost” images – the appearance of several images when looking at one object
Poor night vision
Noticeably worse vision in one eye
Double vision in one eye
Treatment for Keratoconus
In the early stages, keratoconus is essentially a mild astigmatism. As such, it can be treated in similar ways:
Contact lenses or glasses are an effective treatment for most cases of keratoconus, this method adjusts focus to correct visual distortion.
Gas permeable (GP) lenses: for patients whose condition has progressed, GP lenses will correct for the misshapen cornea by covering, or masking, it with the smooth outer surface of the contact lens.
Eye surgery: in the small percentage of cases that contact lenses cannot correct, surgical options such as corneal ring implants, collagen cross linking and corneal transplantation are available to repair the irregular shape of the eye. However, laser surgery is not an option, as there is a high probability of further damaging the cornea.