What is Keratoconus?
The term, “Keratoconus” refers to an eye condition involving the cornea, the clear window at the front of the eye, thinning and warping into a cone-like bulge. This condition can do a great deal of harm to your vision. Normally the cornea maintains a curved, dome-like shape. This allows the cornea to refract light onto the back of the eye, in such a way that it creates a clear image to send to the brain where it is interpreted. When the cornea takes on a more conical shape, this scatters the light as it comes in, sending light to several different points on the retina, creating blurring of vision, distortion of vision, increased sensitivity to light, glare and mild eye irritation. Dr. Joseph Zelasko, O.D. of Century Eye Care in Tacoma, Washington is happy to be your go-to doctor for this and all other eye care needs.
When Does Keratoconus Emerge, and What Causes It?
“Puberty is generally when keratoconus begins to emerge. It begins with mild astigmatism and myopia,” explains Dr. Zelasko. “Although it usually affects both eyes, symptoms may be different in each individual eye. Usually keratoconus progresses quite slowly, getting worse over the course of roughly 10 or 20 years and then ceasing abruptly.”
Scientists are not sure what, exactly, causes a person to develop keratoconus. However, many studies seem to indicate that it is linked to genetics. This is based on statistics that 10% of all people who develop keratoconus have a previous family history of the condition. Excessive eye rubbing and other similar eye injuries, as well as certain eye diseases such as retinopathy of prematurity, and systemic diseases such as down syndrome also seem to be linked to the development of keratoconus.
Diagnosis and Treatment
Keratoconus can often be discovered during the course of a routine eye exam, through tests that help to determine the exact shape of the cornea. A slit-lamp examination is the most popular test used to diagnose keratoconus. This test involves your eye doctor directing a vertical beam of light onto your eye, then using a low-powered microscope to look at your eye to evaluate the shape of your cornea. Optical scanning techniques, such as optical coherence tomography and corneal topography may also be used to create a digital topography map of your cornea's surface and measure the thickness of the cornea.
Treatment depends on how severe symptoms have become. In the beginning the cornea still has some semblance of a normal shape, and eyeglasses or soft contact lenses may be effective for vision correction. As the condition progresses, however, glasses and soft lenses are no longer effective, but rigid or hybrid contact lenses may still be worn to ensure that light entering the eye is refracted properly. Once symptoms have reached more sever levels, various other treatments are available, such as intacs. These small, curved implantable corneal devices help to reshape the cornea into a more dome-like shape, correcting refractive errors caused by the abnormal shape of the cornea. However, in about 10 to 20 percent of cases, good vision is impossible by any other means besides a corneal transplant. In a corneal transplant, your eye care professional removes the diseased cornea and replaces it with a healthy donor cornea. Eye care professionals prefer to avoid this procedure if possible, however, because in some cases it can take a full year to recover good vision after a corneal transplant.
For questions and more information, contact Dr. Zelasko today.