Keratoconus is anÂ eye diseaseÂ that affects the structure of the cornea. TheÂ shapeÂ of the cornea gradually over time changes from the ordinary round shape to a cone shape. The eye bulges out causing vision distortions and problems.
Causes, incidence, and risk factors
The cause is not known, but the predisposition to develop keratoconus is probably commonly present from birth. Keratoconus is thought to involve a defect in collagen, the tissue that delivers strength toÂ the cornea and gives it itâs round shape.
Some researchers believe that allergy and eye rubbing may speed up the damage.
The initial symptom is subtle blurring of vision that cannot be corrected with glasses or contact lenses. (Vision canÂ frequentlyÂ be corrected to 20/20 with Scleral contact lenses.) Over time, patients may have eye halos, glare, or otherÂ night visionÂ problems.
Most people who develop keratoconus have a history of beingÂ nearsighted. The nearsightedness tends to become worse over time. As the problem gets worse, astigmatism develops.
Signs and tests
Keratoconus is often discovered during ones youth. We are now able to detect the presence of keratoconus well before subjective symptoms develop.Â Corneal TopographyÂ and Aberrametry measurements have become the standard of care in diagnosing and management of keratoconus. A computerized system images the shape of the cornea together with the entire optical system by taking tens of thousands of data points. The results are instantly analyzed and wave front topography maps are generated. These printouts will show Dr. Azman an eye-map-print (just like a finger print) of the location and severity of any corneal distortion and high order aberrations (HOA).
Specular Microscopy is noninvasive photographic technique that facilitates accurate and precise diagnosis ofÂ corneal diseaseÂ in the back part of the cornea (endothelium). This instrument can pick up early signs of corneal edema, which cannot be picked up on routine examination. If there is any indication of corneal disease, such as keratoconus or edema we might recommend a different treatment modality.
Contact lensesÂ are the main treatment for most patients with keratoconus. However very specialized designs have been developed that improve vision and comfort far beyond yesterdayâs lenses. In addition, soft lenses, RGP lenses, hybrid lensesÂ scleral lenses, PVR PROSE Treatment, and EyePrint PROÂ ,can now be designed toÂ provide excellent visual results fro patients withÂ keratoconus.
The last remedy for keratoconus to be considered may be aÂ corneal transplant, also called a penetrating keratoplasty (PK orÂ PKP). Even after a transplant, you most likely will need glasses or contact lenses for clear vision. For many years, the only surgical treatment wasÂ corneal transplantation.