Keratoconus is an eye disease in which the central or surrounding cornea gradually becomes thinner. The cornea is one of the eyeball parts that interfers directly on the vision. Light enters the eye through the cornea and focuses the light rays so that we can see clearly.
The uniformity of the cornea changes to a cone shape, causing abnormal astigmatism, which distorts the image and reduces vision.
Keratoconus is the main reason for corneal transplantation in young patients. The older the disease begins, the greater the risk of rapid progression, although it is not uncommon for the disease to continue to change in the 30s and 40s.
In patients with keratoconus, the cornea is shaped like a rugby ball (conical) instead of a soccer (spherical). Therefore, the patient loses visual acuity and may need a corneal transplant.
Keratoconus is inherited from parents to children in 25% of cases. In other cases, it appears only occasionally and may be linked to a complex hereditary process that is still under investigation.
Problems related to eye irritation are also frequent. It is a serious disease caused by changes in the collagen fibers that form the stroma (the hardest part of the cornea). This change causes the cornea to gradually increase its curvature, which acquires a conical (not round) shape, causing a loss of vision.
Keratoconus usually affects both eyes, usually asymmetrically. Among the eye diseases that are considered to be “minor”, the following stand out
Keratoconus usually begins in adolescence, most of those affected are between 20 and 30 years old and 73% of cases are diagnosed before the age of 24. Remember that the younger you are, the more likely you are to get an infection and the faster it will develop. In these cases, keratoconus surgery is usually necessary.
CAUSES:
Although the cause is unknown, it has a clear genetic component, as it is hereditary in 10% of cases. Sometimes, family history is not known in a family because there is a background pattern that cannot be found outside a thorough physical examination.
On the other hand, it should be noted that keratoconus has also been observed to occur frequently in connection with the habit of straining the eyes, which is a common symptom in patients with ocular allergies, for example. Frequent repetition can damage the cornea.
This eye disease is linked to genetics, as 10% of those affected have a family member with keratoconus, but it can also appear suddenly.
Keratoconus may also be associated with other things:
- Prolonged contact lens wear.
- Genetic and hereditary factors. Therefore, it is important that the first relatives (usually siblings and children) go for an eye examination when the first diagnosis of keratoconus is made.
- It may be associated with the presence of allergies, mainly ophthalmic, as itching often causes ocular irritation. For this reason, it is very important to ask patients or their relatives if they rub their eyes and why they do it, so that they can start treating ocular allergies if any, and discontinue any kind of treatment altogether because it hurts them more.
SYMPTOMS:
They usually appear during puberty, with a rapid increase in myopia and astigmatism, with progressive decrease in visual acuity without glasses. In the first stage, keratoconus shows only an increase or decrease in vision, with no other related symptoms.
In these cases, keratoconus is usually diagnosed by a general examination, especially in cases where there is a sudden increase in nearsightedness or astigmatism.Keratoconus can occur in one eye, although it usually develops on both sides.
The most common symptoms are:
- Photophobia or high sensitivity to light.
- mild eye pain.
- Astigmatism and myopia.
- intolerance to contact lenses and frequent changes of prescription, often with astigmatism due to defects on the surface of the cornea. In fact, the onset of the disease is a sudden increase in astigmatism. Astigmatism is a type of refractive error that usually remains stable without sudden changes in the prescription. This is one of the most important signs to suspect keratoconus. It is important that any patient with a sudden increase in this refractive error, especially if they are a child or young adult, have a comprehensive eye exam to rule out the presence of keratoconus.
TREATMENT
Depending on the stage of the disease, there are different treatment options.
- Rigid therapeutic contact lenses: In the first stage, small hard contact lenses are used to widen the cornea and allow light to pass through the cornea effectively and avoid distortion of vision. In most cases, keratoconus does not require surgery and can be treated with glasses or contact lenses to correct the problem. However, in approximately 10-20% of patients, keratoconus surgery is necessary in the hospital, especially if it is progressive or with insufficient vision correction.
- Intracorneal rings; A small incision is made in the cornea to insert the ring for support. The ring compresses and stretches the cornea, allowing light to enter the cornea in a way that restores vision. Current treatment can slow the disease and improve vision. In some cases, surgical treatment may be necessary, such as an intrastromal ring. the arrangement of the cornea or corneal integration, a procedure proven to reduce the progression of keratoconus. It consists of implanting an intracorneal ring, which changes the curvature of the cornea without passing through it, thus improving vision.
- Crosslinking: This procedure may be recommended as an adjunct to the intracorneal ring. In this treatment, a source of ultraviolet light and riboflavin is placed in the eye to help connect and strengthen the collagen fibers of the cornea, expanding and reducing keratoconus.
- Corneal transplantation: If the first treatment does not stop the progression of keratoconus, the latter method should be used. Nowadays, the procedure only allows the replacement of the affected part of the cornea. This reduces the chances of rejection and the recovery time is short. In advanced cases we can opt for keratoconus surgery for corneal transplantation, which today is usually used selectively, when it is only necessary to replace the affected part, and not all the tissue.
- Keratoconus surgery is becoming more and more common, but if we detect it correctly at the beginning and apply the appropriate treatment in early stages, surgery can be avoided.
HOW DO I KNOW IF I HAVE KERATOCONUS?
The most important symptom is the progressive loss of vision that cannot be corrected even with glasses. It must be taken into account that it is not the same that the vision is changing, which is a normal complementary phenomenon and it is corrected with glasses and it is possible to reach 100% vision. When there is a beginning of keratoconus, vision is decreasing and even with glasses you can not reach 100% vision or it is difficult to reach it. In addition, when you have keratoconus, the factor that varies the most in vision is astigmatism, which is normally a refractive defect that does not change abruptly and usually does not increase much over time.
There is no special method to prevent this eye disease.
Periodic eye examinations are recommended, as early detection is important in the treatment of the disease, especially in young patients, as they are at greater risk.
For those who have this disease in their family, it is recommended to periodically go for a check-up to check eye health properly.