Keratoconus, often abbreviated to "KC", is a non-inflammatory eye condition in which the normally round dome-shaped cornea progressively thins causing a cone-like bulge to develop. This results in significant visual impairment. The cornea is the clear window of the eye and is responsible for refracting most of the light coming into the eye. Therefore, abnormalities of the cornea severely affect the way we see the world making simple tasks, like driving, watching TV or reading a book difficult.
In its earliest stages, keratoconus causes slight blurring and distortion of vision and increased sensitivity to glare and light. These symptoms usually first appear in the late teens and early twenties. Keratoconus may progress for 10-20 years and then slow or stabilize. Each eye may be affected differently.
Eyeglasses or soft contact lenses may be used to correct the mild nearsightedness and astigmatism caused in the early stages of keratoconus. As the disorder progresses and the cornea continue to thin and change shape, rigid gas permeable contact lenses are generally prescribed to correct vision more adequately. The contact lenses must be carefully fitted, and frequent checkups and lens changes may be needed to achieve and maintain good vision.
Newer surgical options like intacs, collagen cross linking, phakic ICL are options in mild to moderate cases.
In severe cases, a corneal transplant may be needed due to scarring, extreme thinning or contact lens intolerance. This is a surgical procedure that replaces the keratoconus cornea with healthy donor to quickly clear the lens while it is still in the eye so that it does not need to be removed in the event that dust becomes trapped underneath.
Q: What is difference between keratoconus and "common" astigmatism and what do the numbers mean?
A: Astigmatism is a common condition where the curvature of one or more of the optical surfaces of the eye (the cornea and lens surfaces) are more "round" in one direction than the other. In "regular" astigmatism the maximum and minimum powers are aligned at 90 degrees to each other while in "irregular" astigmatism they do not align. An egg is a good example of a surface with "regular astigmatism". Keratoconus is a degenerative condition where the cornea thins in affected areas. This can lead to astigmatism - often regular at first but becoming increasingly irregular as the disease progresses.
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