Keratoconus is a disease that occurs in the cornea and usually appears between adolescence and 30 years of age. It consists of a progressive thinning, weakening and deformation of the cornea. This causes high irregular astigmatism and, as a consequence, poor vision. Irregular astigmatism increases as the disease progresses and cannot be corrected well with glasses or traditional contact lenses.
If a patient complains of not seeing well despite wearing glasses or contact lenses, or needs frequent astigmatism prescription changes, keratoconus should be suspected. This is even more so if he or she is constantly rubbing his or her eyes, for example, due to an eye allergy. It is important to avoid eye rubbing.
There are mild forms of keratoconus that do not produce obvious visual alterations, but it is important to diagnose and take into account before performing eye surgery.
It is recommended that the relatives of patients with keratoconus have check-ups with the Ophthalmology specialist, since, even though they may not notice visual problems, they could be carriers of the disease.
How is keratoconus diagnosed?
Special diagnostic tests are necessary to detect keratoconus. More advanced cases can be detected as an elevated astigmatism prescription, a basic ophthalmologic examination, and a corneal anterior corneal topography.
However, to make an early diagnosis, special tests such as corneal back topography, full corneal thickness measurements, corneal biomechanics tests or corneal epithelial mapping are required.
What is the treatment of keratoconus?
There are different treatment options, depending on the stage of the disease:
- In milder cases, good vision can be achieved with glasses. When good visual acuity is not achieved with glasses, correction is attempted with semi-rigid or hybrid contact lenses, and there are also special contact lenses for keratoconus. They should always be fitted by experts.
- In some cases, it may be necessary to resort to surgical treatment, such as intracorneal rings or corneal crosslinking. These two treatments stop the progression of keratoconus and, in some cases, reduce corneal astigmatism, improving the quality of vision. The aim of these treatments is to avoid corneal transplantation (also known as keratoplasty), a treatment that must be resorted to in the most severe cases.
What does corneal crosslinking consist of?
It is a procedure that has been shown to slow the progression of keratoconus in more than 90% of patients. It consists of applying drops of riboflavin (a photosensitizing vitamin) to the cornea and then applying low-power ultraviolet radiation to strengthen the corneal collagen.
With this treatment we seek to slow the progression of keratoconus. It is indicated in cases of keratoconus that show progressive degeneration but still maintain good visual acuity.
What are intracorneal rings for keratoconus?
They are semicircular implants made of acrylic material and have a mechanical effect. They act by flattening the central cornea. Often they also stop the progression of keratoconus. When implanting them it is necessary to create a channel inside the cornea. ClÃnica Villoria uses a femtosecond laser to create this channel. With this method they gain safety and precision when implanting the rings.
Keratoplasty or corneal transplantation as a last resort
Early detection is essential to avoid very advanced cases of keratoconus, which require corneal transplantation.
Currently there are lamellar transplantation techniques that allow selective transplantation of the layers of the cornea damaged by keratoconus (more superficial layers of the cornea), while preserving healthy tissue (endothelium). This improves the visual prognosis of patients and increases the safety of the technique.