Overview – What is it?
Keratoconus is a disorder of the cornea which occurs when the cornea thins and bulges outward gradually.
The risk factors for this disorder include rubbing the eyes vigorously and having certain conditions like asthma. Some of the symptoms experienced by a person with keratoconus are blurred vision, clouding of vision and increased sensitivity to light.
It can be diagnosed through tests like keratometry, eye refraction and computerised corneal mapping.
The treatment for this eye problem can be done using lenses or surgery.
Even though it cannot be prevented, keratoconus can be handled by reducing the risk factors that lead to it
Causes – What causes it?
Keratoconus has no exact known cause and therefore the risk factors for the condition are believed to increase the chance of getting it. The risk factors are:
- Family history: One is at an increased risk of the condition if a family member has had it previously.
- Certain conditions: Having some health conditions such as asthma and down syndrome puts a person at an increased risk of getting keratoconus.
- Rubbing the eye: Rubbing the eyes vigorously can also increase the chance of getting keratoconus
- Exposure to ultraviolet rays from the sun: Direct exposure to the sun also increases the risk of keratoconus.
Symptoms – What do you feel?
- Worsening or clouding of vision
- Blurred or distorted vision
- Increased sensitivity to light
- Having double vision
- Sudden change in vision in one eye
- Frequent change in eye glass prescription
Diagnosis – How do you diagnose it?
- Initial consultation: Diagnosis of keratoconus begins with the doctor finding out your medical history, family history and doing a physical exam after which other tests may be done to determine the state of the cornea. These tests include:
- Keratometry: In this test, a circle of light is focused on the cornea and the reflection is measured to determine the shape of the cornea.
- Eye refraction: A special instrument to measure the eyes to help in determining vision problems by changing lenses to know which combination of lenses gives you the sharpest vision.
- Slit-lamp examination: This test involves directing a vertical beam of light on the eye surface and viewing the eye using a low-powered microscope.
- Computerised corneal mapping: Uses special photographic tests like corneal topography to record images of the cornea which helps in creating a detailed map of the shape of the cornea’s surface. It is also used in measuring the thickness of the cornea.
Treatment – How do you treat it?
The treatment of keratoconus depends on the severity of the condition. The treatment options are as follows:
- Using lenses: Different lenses are used to correct different issues. Examples of these lenses are:
- Soft contact lenses which are used to correct blurry or distorted vision in the early stage of keratoconus. They are changed as the cornea’s shape changes.
- Hard contact lenses which are used to treat progressive keratoconus. They can be made to fit a person’s cornea.
- Hybrid lenses are contact lenses that have a rigid centre which has a ring around the outside to make the lenses more comfortable especially for people who find it difficult to adjust to hard contact lenses.
- Scleral lenses are used in advanced keratoconus that involves having very irregularly shaped cornea.
- Piggyback lenses are usually recommended to be placed on top of hard contact lenses if the rigid lenses are uncomfortable.
- Surgery: This is used if there is scarring of the cornea, poor vision even with the highest prescription of contact lenses and extreme thinning of the cornea. The surgeries that can be done to correct keratoconus include:
- Corneal inserts which involves placing very small, clear, crescent-shaped plastic inserts in the cornea to flatten the cone, to support the shape of the cornea and to improve vision.
- Cornea transplant: Transplant is used for people with corneal scarring or extreme thinning. The types of transplant surgeries are:
- Penetrating keratoplasty which is a full corneal transplant and involves removing the full thickness portion of the central cornea and replacing it with tissue from a donor.
- Lamellar keratoplasty on the other hand, which is a partial thickness transplant that involves replacing only a section of the cornea’s surface.
- A deep anterior lamellar keratoplasty (DALK) which is used to preserve the inside lining of the cornea and is known as the endothelium to help prevent its rejection after a full thickness transplant.
In the case of chronic hives, management is necessary by avoiding the triggers for this condition.
Prevention – How do you prevent it?
Since there is no specific way to prevent keratoconus, the best way would be to reduce the risk factors for the condition by:
- Getting regular eye check-ups especially if you a have family history of the condition
- Refrain from rubbing the eyes
- Getting treated or managing conditions that are associated with keratoconus such as asthma and down syndrome