Keratoconus: what are the causes and symptoms?
Keratoconus is an eye disease that is usually detected around the age of 15. In this guide, we take a look at this condition that evolves over the years. What is a keratoconus? What are the symptoms and treatments? Find out here in our complete guide.
What is a keratoconus? | Definition
To fully understand what a keratoconus is, we must first look at the cornea.The cornea is a transparent structure located in front of the iris and is essential for proper vision. Light enters the eyes through a film of tears and then passes through the cornea.The word keratoconus comes from the Greek "keratos'' for cornea and "konos" for cone. It means that the cornea deforms to take on a cone shape, which distorts vision since the eye no longer properly focuses the light rays in the same way. With a prevalence of around one case per 2000 people, this condition is quite common. It usually occurs during puberty and the condition may continue to develop into adulthood. It causes significant visual disorders that require treatment. Do you think you have it? Make an appointment with one of our specialists for an eye exam.
What causes keratoconus?
Specialists are uncertain as to the exact cause of keratoconus. However, it is recognized that this visual disorder can be associated with different factors:
- Hereditary keratoconus: some people affected by this disease have a family member who also suffers from it. But only a small percentage of patients suffer from an inherited form, as keratoconus usually appears sporadically.
- Keratoconus is linked to health problems: it can be caused by pathologies, such as atopy, Down syndrome or craniofacial dysostosis.
- Keratoconus is linked to visual disorders: it can be caused by pathologies, including vernal keratoconjunctivitis or retinopathy of prematurity.
- Keratoconus is linked to eye damage: continuous rubbing of the eyes can damage the eye and cause of keratoconus. Ocular allergies and the use of contact lenses for long periods can cause excessive friction.
Since keratoconus appears after puberty, it is also suspected that hormonally changes may be a factor.
What are the symptoms of keratoconus?
Usually, keratoconus is a bilateral condition, as it affects both eyes at the same time. However, one eye can be affected before the other and both eyes are not always affected with the same severity.When the cornea is deformed into a cone shape, the central part becomes thinner, and the tissues then become more fragile. The body tries unsuccessfully to repair the surface of the eye and the cornea becomes cloudy through this healing process. Other symptoms include:
- distorted vision
- blurred vision
- sensitivity to light
The course and severity of the condition can range from mild astigmatism to thinning of the cornea.
How to live with keratoconus?
For the vast majority of affected people, wearing contact lenses is enough to live with keratoconus comfortably. And in order to live better with this disease, it’s important to understand it well, to have it diagnosed, and to have regular follow-ups.
Understand the disease well
Take time to learn as much as possible about the disease. First, do your research and jot down all your questions. You can then make an appointment with a specialist to obtain a precise diagnosis, but also to ask your questions. Note that this condition generally stabilizes after 40 years of age, which makes it easier to live with keratoconus on a daily basis.
Have the condition diagnosed and have regular follow-ups
Keratoconus can be detected through a regular optometric check-up. You should know that there’s no way to prevent this disease or predict its evolution. Once the diagnosis is established, it is necessary to have regular follow-ups with an ophthalmologist. The ophthalmologist may choose to perform specific additional examinations to provide a more precise diagnosis:
- Corneal topography (or photokeratoscopy): This involves taking a photograph of the cornea. The ocular surface will be studied in detail using the topographic map obtained.
- Keratometry exam: This exam aims to measure the cornea’s curvature radius to determine the exact curvature.
- Optical coherence tomography: This provides high-resolution cross-sectional images of the eye. This non-invasive method can be completed in seconds.
What are the treatments for keratoconus?
The vast majority of people with keratoconus wear contact lenses. However, wearing prescription glasses may be an option under certain conditions.
Eyeglasses with astigmatic lenses can correct keratoconus. They make it possible to achieve a comfortable quality of vision. This solution is often offered to younger people who are starting to develop the symptoms of keratoconus. After a while, the course of the disease will make treatment with glasses insufficient. It will then be necessary to wear contact lenses.
Contact lenses for keratoconus
There are different types of lenses to correct vision problems caused by keratoconus. The lenses are custom-made to correct a large part of the irregularities in the cornea. They thus make it possible to regain satisfactory visual acuity, both near and far. These lenses should be adapted and readjusted whenever necessary. There are hard lenses that were, for a long time, the only option available. They are very effective, but not everyone finds them comfortable. Scleral lenses are another solution that are more comfortable. With their large diameter, they push on the conjunctiva of the eye and not on the cornea. In case of intolerance to lenses or if the quality of vision is insufficient, there are various surgeries that can improve vision for people with this condition.
What does a keratoconus surgery consist of?
Several surgical techniques exist for keratoconus. Their use depends on its severity.
The technique of cross-linking
This technique helps to strengthen the cornea’s collagen with drops of vitamin B and using UV light. This slows down the deformation and stabilizes the disease’s progression.
The placement of intracorneal rings
Intracorneal rings are introduced into the thickness of the cornea to tighten the central cornea. They are therefore used to flatten the cone and reduce corneal deformation and irregularity.
Corneal transplantation is used only for the most severe cases. The operation involves changing the central part of the cornea. This requires using the healthy cornea of a deceased donor. These operations help improve the quality of life for people with keratoconus. Note that this disease happens to be almost asymptomatic in its early stages. In general, it is advisable to have regular ophthalmic exams, especially for people who have a family history of this pathology.