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Eye diseases


The most common corneal dystrophy and the leading cause of corneal transplantation among young people.
A sudden increase in astigmatism is the main sign of suspected keratoconus.
It can be hereditary, whereas rubbing the eyes repeatedly also favours its development.

What is keratoconus?

Keratoconus is a degenerative disease caused by the alteration in the collagen fibres that make up the stroma (the thickest part of the cornea). This alteration causes a gradual increase in the curvature of the cornea, which becomes conical (instead of rounded), resulting in gradual vision loss.

It tends to affect both eyes, usually asymmetrically, and is the most common corneal dystrophy, which is present in about 1 in every 2,000 people in Spain.

It is also common for you to experience intolerance to contact lenses and frequent changes in prescription, mainly as regards astigmatism (link), due to the irregularity that is generated on the surface of the cornea. In fact, the appearance or sudden increase of astigmatism – a type of refractive error that generally remains stable and does not evolve – is one of the main signs of suspected keratoconus.

As a rule, this disease starts at puberty, and most patients who suffer from it are in their 20s or 30s, with 73% being diagnosed before reaching the age of 24. You should bear in mind that the younger you are, the greater the risk that keratoconus will evolve and do so more quickly.

Although it is not known exactly what causes it, there is a clear genetic component, as it is hereditary in 10% of cases. Sometimes the family history is unknown by the family, as there are subclinical forms of keratoconus that do not appear and are not detected, except with a complete ophthalmological examination.

On the other hand, a higher incidence of keratoconus has also been seen associated with the habit of rubbing the eyes, a common gesture, for example, in patients with eye allergies, and which, when performed repeatedly, contributes to weakening the collagen network of the cornea.

Current treatments allow us to both stop the disease and improve vision.

Many cases do not require surgery and can be treated with the prescription of appropriate glasses or contact lenses to correct the visual error. However, in about 10-20% of patients it is necessary to operate on keratoconus, especially when it progresses or the use of optical correction is not enough to guarantee a good vision quality.

One option we offer is the implantation of intracorneal rings that modify the irregular curvature of the cornea and, thereby, improve vision. However, they do not stop the evolution of keratoconus, something that we do achieve with the crosslinking technique, which “hardens” the cornea so that it does not continue to deform. For advanced cases, we can opt for corneal transplantation, which can replace only the affected tissue layers or the entire cornea.

The first cause of corneal transplantation in young patients is keratoconus, although, if we diagnose it correctly from the beginning and apply the appropriate treatment in the early stages, we can slow down its advance and avoid transplantation.

Ask for an appointment at Miranza and take care of your eye health.