Keratoconus is a pathology that mainly affects young people and its causes are unknown. Dr. Pastor, a specialist at the Oftalvist Ophthalmology Clinic, explains how this eye disease develops.
Keratoconus is an ocular alteration, specifically of the cornea, which produces a distortion of images and a decrease in vision, affecting mainly young adults and adolescents.
Keratoconus is caused by a progressive thinning of the corneal thickness in the central and paracentral zone of the cornea as well as a modification in the corneal curvature.
Thus the spherical shape of the cornea changes to a conical one.
As a consequence of this change, irregular corneal astigmatism and myopia will be caused, resulting in image distortion and decreased vision.
Keratoconus, possible causes
The cause and possible mechanisms of keratoconus production are still unresolved.
Like many idiopathic diseases, there is always a multitude of predisposing factors and theories in the literature to try to explain the origin of keratoconus.
- One of the theories is genetic or hereditary. A percentage of patients with keratoconus have affected relatives. Inheritance may be direct, inherited from parents to children, or linked to complex patterns of inheritance with a more sporadic transmission.
- It has also been related to chronic eye scratching. It has been shown that this practice over a prolonged period of time can trigger the development of keratoconus.
- It can also appear as a consequence of persistent minor trauma to the eye, or the use of inappropriately fitted contact lenses.
- There are theories that point to the influence of a hormonal factor, as well as pathologies with systemic collagen alteration.
In mild or incipient cases, good vision can be achieved by correcting the refractive defect with glasses or contact lenses.
In more advanced cases, the use of rigid contact lenses is necessary to correct the irregular astigmatism. The use of these lenses will provide the patient with good vision since at this stage glasses do not provide correct visual acuity.
In cases where contact lenses are not tolerated or do not provide good visual acuity, the treatment would be surgical with intrastromal or intracorneal rings or segments whose objective is to regularize the corneal curvature and reduce irregular astigmatism.
In the final stage, when the pathology is very advanced, in the most severe cases the indicated treatment is keratoplasty or corneal transplantation. Nowadays transplantation can be performed in many cases by selectively replacing the affected layers of the cornea and preserving healthy tissue.
At any stage except the final stage, corneal cross-linking can be performed, a procedure that has proven to be effective in strengthening the corneal structure and slowing the progression of the cornea.