The cornea is the transparent and avascular anterior tissue of the eye, which resembles the crystal of a watch. The cornea consists of 5 layers: the epithelium, the Bowman membrane, the stroma, the Descemet membrane and the endothelium, the main functions of which are the protection of intraocular content and light reflation.
Keratoconus represents one of the most frequent degenerative corneal pathologies in our environment. It is estimated that there will be around five hundred undiagnosed patients on our island. This disease is characterized by the appearance of a progressive deformity (ectasia) at the level of the corneal structure (our external lens) due to a congenital weakness.
The suspicion of suffering from keratoconus is established when a young person with high astigmatism and myopia in their glasses does not achieve good vision with the need for frequent and constant graduation. These symptoms are shown to be aggravated with repeated eye rubbing.
This disease in advanced stages can cause legal blindness despite the usual means for its correction (glasses, contact lenses). In these stages the classic practice so far indicated the performance of a corneal transplant, with the consequent disorder to the patient and the health expenditure involved, but the emergence of new techniques have shown, in those cases indicated, that its performance stops the progression of this degenerative process, avoiding in a high percentage of patients the performance of transplants, and improving the visual quality and tolerance of other treatments, such as contact lenses.
Specifically, one of these techniques, the implantation of intracorneal rings, has been carried out for years with excellent results to stop and stabilize the disease. These are circular segments made of biocompatible material that stabilize the cornea due to its structural effect and regularize astigmatism.
If they are indicated correctly and are performed with the appropriate technique, the percentage of associated complications is minimal.
Another of the novel techniques consists in applying ultraviolet radiation radiation type A (UVA rays) on the cornea to which we have previously treated with vitamin B2 (riboflavin). This manages to “harden” these corneas that due to their weakness suffer from keratoconus.
Pterygium or pernal
Pterygium is a disease that affects the conjunctiva and cornea. The conjunctiva is a thin transparent membrane that covers the sclera (the white portion of the eye). It is there where the disease begins: there is an exaggerated growth of the conjunctiva in the portions exposed to the sun.
It can produce a wide variety of symptoms that can range from the sensation of a foreign body and red eye, to the alteration of vision due to the induction of astigmatism or even invasion of the visual axis, it can also be aesthetically annoying.
In the initial phases, when the sensation of burning and dryness is light, it can be mitigated with lubricants and vasoconstrictors. In advanced stages surgery is required to eliminate the pterygium and replace it with a healthy conjunctiva. Each surgery is different depending on the particular needs of the patient.
In the Canary Islands we have the highest incidence in Spain in cases of pterygium, which is common in eyes that have been subjected to sun overexposure without adequate protection. It is essential for its prevention that we use sunglasses that prevent the radiation of ultraviolet rays. Failure to perform this type of surgery in advanced cases can lead to progressive loss of vision.