Keratoconus usually appears throughout adolescence and evolves over time.

Keratoconus is a non-inflammatory eye disease that affects the cornea, the transparent structure that covers the frontmost part of the eye, causing a progressive thinning and curving of the cornea, acquiring a conical and irregular shape.

What are the consequences of keratoconus?

The consequence is an irregular astigmatism that results in a significant decrease in vision. If this is left untreated, it may progress until it is only possible to treat with a corneal transplant.

When does keratoconus begin?

It starts from puberty onwards and then progresses slowly, although it can remain stable at any time. Both eyes are affected in almost every case.

What factors contribute to the development of keratoconus?

The role of genetics has not been fully defined. The descendants appear to be affected in only 1% of cases and there is some tendency for inheritance to be autosomic dominant with incomplete penetrance. It can be found in association with systemic diseases and syndromes such as Down syndrome, Marfan syndrome, retinitis pigmentosa, atopic patients and patients with vernal keratoconjunctivitis, etc.

At the Clínica Oftalmológica Castro we recommend regular ophthalmological check-ups, being extremelly important the corneal topography check up, a fundamental test for diagnosis and monitoring, as it evaluates the corneal surface and its irregularities and curvature.

What is the treatment for keratoconus?

Currently, existing treatments have two objectives:

  • Stabilisation of the shape of the cornea (cross-linking and intrastromal rings) and, therefore, of the progression.
  • Visual rehabilitation.

At the beginning of the disease, when the cornea is not yet deformed, the astigmatism produced can be corrected and good vision can be achieved with glasses. As the disease progresses, it becomes impossible to correct this defect and the next step will be including rigid contact lenses.

However, these measures do not prevent the progression of keratoconus. It is therefore essential to combine surgical techniques such as corneal cross-linking and the implantation of intrastromal corneal rings.

Corneal transplantation is reserved for very advanced cases in which other treatment options are not possible.


This treatment strengthens the internal structure of the cornea, making it more rigid, and increasing its resistance to deformation.

Riboflavin eye drops are placed onto the cornea and a low-dose ultraviolet A light source is applied too. In this way, a chemical photopolymerisation reaction is carried out, increasing the bonds of the corneal collagen molecules, reducing elasticity and improving stability, rigidity and resistance of the cornea, thus slowing down the progression of keratoconus.

It is a simple and minimally invasive procedure.

Intrastromal corneal ring implantation

This surgical technique also stops and stabilises the progression of keratoconus.

It also reduces corneal deformation, regularises the corneal surface and corrects irregular astigmatism.

Beforehand, a thorough and complete ophthalmological examination must be carried out to determine how many rings should be implanted and in what place.

One or two semicircular segments of acrylic material are implanted in the thickness of the cornea and tunnels are made inside the cornea. At Castro Ophthalmology Clinic, we carve these tunnels and make the incisions for their implantation with VisuMax femtosecond laser, which provides greater precision, speed, and safety, with a lower risk of complications.

It is an add-on technique, minimally invasive, highly tolerated (no rejection) and reversible, so that the rings can be removed in any future circumstance.

Visual recovery is quick after surgery and results are stable. They do not compromise the possibility of a future transplant and, allow better adaptation of contact lenses and visual rehabilitation by regularising the corneal surface.

At Castro Ophthalmology Clinic we want to emphasise that the treatment of patients with keratoconus must be global. This way, we will not only stop the progression of the disease but we will offer the best possible and appropriate visual rehabilitation in each case that will improve visual acuity and quality by using various methods, in which we recommend the personalised adaptation of contact lenses.