Keratoconus is a condition when cornea which is the clear, dome-shaped front surface of the eye — thins and gradually bulges outward into a cone shape. A conical cornea causes blurred vision and may cause sensitivity to light and glare.
Causes are not known, although genetic and environmental factors are risk factors. Around 10% of people with keratoconus also have a parent with the condition.
Following are main risk factors:
- History of family member with keratoconus
- Habit of vigorous rubbing eyes
- associated certain conditions, such as retinitis pigmentosa, Down syndrome, Ehlers-Danlos syndrome, hay fever and asthma
To diagnose keratoconus, ophthalmologist will review your medical and family history and conduct an eye exam. Tests to diagnose keratoconus include:
- Eye refraction to measure patient eyes to check for vision problems
- Slit-lamp examination
- Keratometry determines the basic shape of your cornea. High K readings are suggestive of Keratoconus.
- Computerized corneal mapping.Special photographic tests, such as optical coherence tomography and corneal topography to record images of patient cornea to create a detailed shape map of cornea’s surface. The tests can also measure the thickness of your cornea.
Treatment for keratoconus depends on the severity of condition and how quickly the condition is progressing.
Mild to moderate keratoconus can be treated with eyeglasses or special contact lenses. Patients using rigid or scleral contact lenses need to make sure to have them fitted by an ophthalmologist with experience in treating keratoconus. Patients also need to have regular checkups to determine whether the fitting remains satisfactory.
Corneal collagen cross-linking is a technique that uses UV light and a photosensitizer to strengthen chemical bonds in the cornea. The purpose of the treatment is to halt progressive and irregular changes in corneal shape known as ectasia.
Advanced cases need surgery
Corneal inserts. (intracorneal ring segments) flatten the cone also support the cornea’s shape and improve vision.
Corneal inserts can restore a more normal corneal shape, slow progress of keratoconus and reduce the need for a cornea transplant. This surgery may also make it easier to fit and tolerate contact lenses. The corneal inserts can be removed if required, so the procedure can be considered a temporary measure.
Cornea transplant. If patient have corneal scarring or extreme thinning, they will likely need a cornea transplant (keratoplasty).
Penetrating keratoplasty is a full thickness cornea transplant. In this procedure, doctors remove a full-thickness portion of your central cornea and replace it with donor tissue.
A deep anterior lamellar keratoplasty (DALK) preserves the inside lining of the cornea (endothelium). It helps avoid the rejection of this critical inside lining that can occur with a full-thickness transplant.