Keratoconus is an eye disease that affects the cornea, the first and most important "lens of the eye". In the natural course of this disease, the cornea is progressively deformed causing visual defects such as myopia or irregular astigmatisms that are not correctable with glasses or contact lenses and that lead to a significant decrease of the visual acuity, being able to reach in its later stages to a very severe impairment of vision.
Usually appears between the first and second decade of life, the speed and degree of evolution in each patient and their frequency varies greatly, due to the undoubted improvement of diagnostic methods, it was once believed to be very low and we can now find clinical evidence that speak of up to 6% of the general population. It can affect a single eye, although the most common is that it affects both asymmetrically, both in its evolution and in the degree of affectation.
Causes of Keratoconus
The cause that causes it remains unknown, although it is thought that there is a genetic factor. In addition, it is more frequent in people who usually rub the eyes and with diseases of the collagen or Down Syndrome.
Diagnosis of keratoconus
In order to control and treat the disease, in Ophthalmology consultations, instruments of measurement called surveyors are used . To be precise, it is necessary to examine both the anterior face of the cornea and the posterior one, which is where the first signs of keratoconus. Other devices that can measure the corneal biomechanics or corneal capacities needed to withstand external (eyelid, trauma, rub, etc.) and internal (intraocular pressure) pressures are also employed.
Treatment of keratoconus
The treatment must be integral, adapting to each case, and it must act in two fundamental aspects: to stop the progression of the disease in the cases that prove that it is not stable and, in the cases in which it does not progress, to improve the visual acuity of the patient.
In mild cases of keratoconus and without obvious progression, a good vision can be achieved by correcting it with special glasses or contact lenses. Of these, the most recommended for keratoconus treatment are rigid scleral support contact lenses (ICD) and hybrid lenses (Clearcone).
In more advanced cases or in progression, it may be necessary to resort to surgical treatments , which can be performed through several techniques:
- Cross-Linking Corneal : it is recommended whenever it is suspected or demonstrated progression in the disease, although it should not be delayed in excess, since in very advanced phases that present a great thinning of the cornea would not be indicated. It consists in subjecting the cornea to ultraviolet radiation after the application of Riboflavin (Vit B2) in order to strengthen and stabilize its internal structure. It is an effective treatment and stops its progression in a high percentage of treated patients.
- Intracorneal Ring Implant : In order to treat irregular astigmatism, rings may be implanted in the thickness of the peripheral cornea, which customarily modify the corneal curvature. The rings or segments have been used for this purpose for years with good results, and are now much more effective thanks to the Femtosegundo laser, which designs with absolute precision and safety both the depth and the position of the intra-thorium tunnel where they are to be implanted.
- Corneal transplantation : should be performed in keratoconios that have reached more advanced stages and there is a thinning and severe corneal irregularity, which contraindicate other more conservative techniques. It can be done by selectively replacing the affected layers and preserving healthy tissue (lamellar transplantation), which reduces the risk of rejection and alters the normal corneal structure, or by replacing the cornea in its full thickness when the cornea is so severe that prevent the previous (penetrating transplant).