Keratoconus is a progressive eye disease that affects the cornea part of the eye, and it is estimated to occur in 1 out of every 2,000 people in the general population. The cornea is usually round, but in people with keratoconus, it thins and begins to bulge and distort into a cone-like shape instead. This causes light to be deflected as it heads towards the retina, which can cause a sufferer’s vision to be distorted. Keratoconus can occur in one or both eyes, and it usually begins when a person is in their late teens or early twenties.
What causes keratoconus?
The actual cause of Keratoconus is not known, but it has been associated with a number of potential factors including poorly fitted contact lenses, excessive eye rubbing and over-exposure to ultraviolet rays from the sun.
However, more recent research has found that an imbalance of enzymes within the cornea may be responsible for it weakening, and subsequently causing keratoconus. The imbalance makes the cornea much more susceptible to oxidative damage, which can weaken it and cause it to bulge. Research has also shown that keratoconus often affects more than one member of the same family, and experts believe this is because the risk factors for oxidative damage and weakening of the cornea include a genetic pre-disposition.
Symptoms of keratoconus
The earliest symptoms of keratoconus are normally blurred vision, frequent changes in your glasses prescription, or vision that cannot be corrected using glasses. It is most commonly diagnosed in people who are in their late teens or early twenties.
In its early stages, diagnosing keratoconus is particularly difficult, particularly as many of the symptoms in the list below are universal to many other conditions. However, some of the symptoms you might experience include:
Difficulty driving at night
Increased sensitivity to light
Headaches and eye pain
A ‘halo’ around lights
The changes in the shape of the cornea can happen quickly or may occur over several years. However, if you are experiencing the symptoms listed above you should visit your ophthalmologist as soon as possible, as they can also be indicative of other eye-related conditions.
We can usually diagnose a child using a slit-lamp examination, during which we will take a close look at your eyes and check for:
Scarring at the apex of the cone
Fleischer’s ring (an iron-colored ring that surrounds the cone)
Vogt’s striare (stress lines that are caused by corneal thinning)
We may also choose to measure the curve of the cornea which can be done using a device that shines a pattern onto the cornea that helps to determine how the eye is curved. Some ophthalmologists use a method called corneal topography, in which a computerized instrument creates a three-dimensional map of your cornea. However, both allow us to assess the extent of the curvature.
Treatment for Keratoconus
The first treatment suggested for keratoconus is usually a change in the prescription of your glasses or contact lenses. There is a specialized procedure known as PTK that can smooth out the scar and improve the comfort of your content lenses as keratoconus can make them difficult to wear.
If this is unsuccessful then we may suggest a process called corneal collagen crosslinking which is effective in tackling the progression of keratoconus and involves the use of implants placed under the surface of the cornea to reduce the cone shape and improve your vision.
As a last resort, we may suggest a corneal transplant. This surgery involves removing the centre of the cornea, and replacing it with a donor cornea which gets stitched into place. However, this procedure almost always requires the patient to wear contact lenses after.
If you have any of the symptoms listed on this page, or any other questions about keratoconus, please contact our office today to learn more at 410-377-2044.