SYMPTOMS
In its incipient phase, which occurs in adolescence, keratoconus causes irregular astigmatism caused by deformation of the cornea. Blurred vision and image distortion are the symptoms of this vision deterioration, which then progresses more or less rapidly over time. The deterioration occurs in daytime vision at any distance (astigmatism and myopia) and also in night vision, with other associated symptoms: photophobia, eye fatigue and irritation. Eye pain can also occur.
The progression of the disease is different in each eye and the existence of keratoconus must be suspected whenever there is a constant modification of the astigmatism and myopia prescription, with the aggravating factor that it cannot be corrected properly with the use of glasses.
TREATMENT
The treatment of keratoconus depends on the moment of diagnosis and the degree of evolution that the disease has reached. Pharmacological treatment (artificial tears and allergy medications) aimed at improving the surface of the cornea can be started at the earliest stage, since the characteristic protrusion of this disease is very mild. The next step is to correct the astigmatism with contact lenses, since with glasses this objective cannot be achieved. Over time, the curvature of the lenses will have to be modified in order to adapt them to the deformation of the cornea or even to combine soft and hard lenses. When correction of visual disturbances with contact lenses is no longer possible, the only treatment option is surgery.
Although until recently only the corneal transplant was available, effective therapeutic techniques have been developed that help avoid a transplant, such as corneal crosslinking and intracorneal ring implantation.
SURGERY
To curb the development of keratoconus, a surgical technique called corneal crosslinking is employed in the early stages of the disease, and consists of the application of riboflavin in the form of eye drops that are activated by subjecting it to ultraviolet light. In this way, the action of the ocular collagen is reinforced in order to give a greater rigidity to the cornea and to avoid its ongoing deformation. However, this treatment does not allow the visual impairment that has already occurred to be reversed.
The surgical option to correct the deformation of the cornea is the implantation of one or two intracorneal rings in the stroma (intermediate layers of the cornea). This improves vision and slows down the progression of keratoconus in most cases.
Finally, if none of the treatments mentioned above prevents the progression of the disease, it will be necessary to resort to corneal transplantation, which in recent times has evolved considerably. Currently, a technique called lamellar surgery is used which, instead of having to transplant the entire cornea, allows only the affected part of the cornea to be transplanted. It is a less aggressive technique, in which the possibility of rejection is reduced in favour of the adaptation of the new tissue to the eye, allowing a faster recovery.
RESULTS
Until the incorporation of all these therapeutic advances, keratoconus was the most important cause of corneal transplantation. However, this option can be avoided in numerous patients. Even so, lamellar transplant surgery offers good results in achieving the visual rehabilitation of our patients.