Keratoconus
Stabilising eyes and improving vision
Keratoconus
Keratoconus is progressive eye condition which affects the stability of the cornea, which is the clear dome front surface of the eye. As the cornea lacks strength, it can change shape causing thinning and bulging at different points. This can cause refractive changes in the eye, effects the quality of vision and can compromise the health of the eye.
Early detection and appropriate treatment is key.
The Human Cornea
The eye is similar to a camera with two built-in lenses to focus light. Without this focus, the image is blurred. Like any camera manufacturer, the lenses must be perfectly shaped to form a sharp picture. The human eye has two lenses – the cornea and the crystalline lens. The cornea is bridge-shaped, providing structural strength and the ability to focus light. Any structural weakness in the cornea can cause the bride to strain and change shape. As this continues, the vision deteriorates and becomes increasingly difficult to correct in glasses.
How are keratoconus and corneal ectasias treated?
It is essential to consider the management as TWO separate arms. Each one requires attention, and while treatments may be combined, both aspects must be considered.
1. Shape Stabilisation
The most critical first step is to prevent things from getting worse. This is achieved with collagen crosslinking.
2. Visual Rehabilitation
There are many ways to improve the quality of vision, ranging from simple glasses in milder cases to highly specialist customised surgical treatments.
Keratoconus FAQ's
What is keratoconus?
The human eye has two built-in focusing lenses. Like a camera, these lenses need to be in the correct shape to provide a clear picture. The first is the cornea, a bridge-shaped structure on the outside of the eye. Keratoconus affects the cornea.
In Keratoconus, the cornea becomes structurally weakened, gradually changing shape and causing worsening blurring of vision.
Why does it affect young people?
As we age, the cornea becomes naturally stronger and stiffens. Keratoconus typically stops progressing beyond the age of 40.
What causes keratoconus?
The causes of keratoconus can be considered under the following titles
Environmental
Keratoconus is more common in people with allergies and atopy, which include asthma, eczema, and hay fever.
Genetic associations
Around 10% of keratoconus is thought to be inherited in an autosomal dominant pattern. Anybody with a first-degree relative with keratoconus is at increased risk.
Other associations
Chromosomal abnormalities
- Down’s syndrome (5.5-15%)
- Turner’s
Connective tissue disorders
- Ehlers-Danlos
- Osteogenesis imperfecta
- Joint hypermobility – MCP and wrists
- Mitral valve prolapse
- Marfan’s
- Crouzons’s syndrome
Ocular disease
- Leber’s congenital amaurosis
- RP
- Aniridia
Does rubbing your eyes make keratoconus worse?
Yes. Everybody needs to avoid rubbing their eyes. This is especially true for children and adults under the age of 40. Eye rubbing is known to contribute to the development of keratoconus.
If you suffer from itchy eyes due to allergic eye disease, it can be challenging to avoid rubbing the eyes. You must see a healthcare professional to help. The use of anti-allergy drops can often be beneficial.
Can my keratoconus improve if I stop rubbing my eyes?
Yes. We often see a slight improvement in the shape of the cornea after people have stopped rubbing their eyes.
Why can glasses not correct my vision?
Scattered light causes blurred vision. Because glasses can correct the lower-order aberrations but not the higher-order aberrations, we mathematically divide the causes of scattered light entering the eye into lower- and higher-order aberrations.
As keratoconus worsens, it causes increased higher-order aberrations that are not correctable by glasses. There are several ways to correct these aberrations. One method is non-surgical, using contact lenses; others are surgical, using different procedures.
Will I go blind?
It is a favourable time in history to have keratoconus. Several significant technological advancements have occurred in the past two decades.
The first was collagen cross-linking, which can now stabilise keratoconus, preventing further progression. The second are many surgical advancements that now allow for many the vision to be restored.
Will I need a corneal transplant?
Worldwide, the number of corneal transplants performed for keratoconus has dramatically fallen. Collagen crosslinking now enables us to stop keratoconus from worsening in most people. Traditional collagen crosslinking freezes the cornea in its current state. It is, therefore, essential to have keratoconus diagnosed and treated early.
Technological advancements with laser eye surgery, customised collagen crosslinking and intrastromal rings now mean the vision can often be improved without ever the need for a corneal transplant.