Keratoconus is an eye disorder in which the cornea gradually thins and swells in the shape of a cone, causing visual distortion. Treatment may include corrective lenses or, in more advanced cases, surgery or corneal transplantation. The assessment of the Polygenic Risk Score for keratoconus is based on the examination of 33 gene polymorphisms.
Genetic testing for keratoconus is included along with 12 other diseases in the Genetic Screening for Sensory Organs and Skin Diseases, Polygenic Risk Score.
Causes and non-genetic risk factors
Keratoconus usually develops between the late teens and thirties and most commonly affects both eyes. The causes are unknown, although genetic and environmental factors are involved in its development. It is estimated that about 1 in 10 people have a family history of keratoconus, and the environmental risk factors described to date are:
- Rubbing the eyes vigorously regularly
- Presence of ocular allergies
- Having certain conditions such as retinitis pigmentosa, Down syndrome, Ehlers-Danlos syndrome, Marfan syndrome, hay fever, and asthma
Symptoms
Keratoconus usually affects both eyes, although it can produce different symptoms in both eyes. Symptoms appear progressively, and among the most common are:
- Blurred vision
- A slightly distorted vision where straight lines may appear crooked or wavy
- Increased sensitivity to light
- Redness or swelling of the eyes
- Aggravation of nearsightedness and/or astigmatism
- Poorly fitting contact lenses
Prevention
There are no effective measures to prevent the onset of keratoconus, although controlling ocular allergies and avoiding rubbing the eyes may help prevent its aggravation. Once it has developed, contact lenses are the primary treatment, although they do not stop the condition's progression. The only effective surgical treatment to date is corneal transplantation.
