It is the progressive deterioration of the curvature of the corneal layer, which is located at the front of the eye and should have a dome curvature, and takes a conical shape. So keratoconus means "conical cornea". Vision gradually decreases as the normally spherical cornea becomes conical.
The cause is not fully known. It has a genetic aspect. The frequency of the disease is more common in people who are allergic and scratch their eyes a lot than in the normal population.
How does keratoconus occur?
In eyes with keratoconus, visual impairment called astigmatism initially occurs. In the early stage, the patient benefits from astigmatic glasses. It is usually of the myopic-astigmatic type. As the disease progresses, the eye continues to become more and more myopic and astigmatic, especially astigmatism progresses very much, the cornea gradually curves forward and becomes thinner, taking on an irregular shape.
Very rarely, hyperopic keratocuneus patients are also encountered. The astigmatism that occurs. The patient cannot benefit from glasses because they are irregular. Usually, the measured astigmatisms and the numbers that the patient sees clearly do not match each other. During this period, hard lenses (special keratoconus lenses) can increase vision. When the disease progresses, hard lenses cannot hold in the eye and fall out. Some of the patients with hard lenses in their eyes cannot use hard lenses due to the discomfort it causes.
Is keratoconus a common disease?
Keratoconus is a disease seen on average in every 2000 people. Its onset usually occurs between the ages of 15 and 20. There is usually a few years between the onset of the disease and diagnosis. It may progress differently in each patient. In some patients, it appears early and progresses rapidly, in some patients it occurs late and progresses slowly.
How is keratoconus diagnosed?
In addition to the standard normal examination, there are two gold standard examinations in the diagnosis of keratoconus: Pachymetry and topography
Pachymetry is the measurement of corneal thickness. It is the first parameter examined in the diagnosis of the disease. It is the most important indicator of the stage of the disease. It plays a role in the decision-making process in many treatments.
Topography is the map of the cornea. of the disease It clearly reveals its characteristic findings. It is also the most important examination in monitoring progress and treatments.
Can keratoconus be treated?
Different treatment applications are performed in keratoconus depending on the period of the disease. In the early stages, glasses are sufficient. As the disease progresses, clear vision can no longer be achieved with glasses. Starting from this period, corneal crosslink treatment can be applied.
Crosslink can be translated into our language as "Cross Linking". In this treatment, special dyes (riboflavin) are applied to the cornea and then UV rays of a certain wavelength are applied. Thus, the damaged front layer of the eye virtually "hardens" within itself and the progression of the disease stops. Visual acuity increases in a significant portion of patients without glasses (without correction). It is preferred for reasons such as having almost no side effects and being the only method that stops the progression. Patients can also benefit from special keratoconus lenses (rigid gas permeable contact lenses).
Corneal Crosslink is successfully applied not only in keratoconus but also in similar diseases such as keratoglobus and pellucid marginal degeneration. All three of these diseases are progressive thinning diseases of the corneal layer, and their basis lies in the disorder of the corneal structure. In the early stages, all three may be confused with each other.
In the advanced stages of keratoconus, vision level decreases even more and contact lenses cannot be worn due to increasing bulge.
Another treatment method is the application of a Ring. It is based on the principle that half rings inserted into the cornea stretch the cornea like a pulley. It does not stop the progression of the disease. As long as the rings remain in the eye, they improve vision. When they are removed, either on their own or by a doctor, vision usually decreases to lower levels than before.
In advanced stages of the disease, the damaged cornea must be replaced with a cornea taken from another person. The surgery is popularly known as eye transplantation. It is known as. This surgery, whose medical name is keratoplasty or corneal transplantation, is actually a tissue transplant rather than an organ transplant. Since the cornea layer (the transparent layer of the eye) is a non-vascular tissue, tissue rejection occurs in other organs. It is very small compared to other transplants (kidney, liver, etc.).
Read: 0
