Keratoconus (ker-uh-toe-KOH-nus) occurs when your cornea — the clear, dome-shaped front surface of your eye — is thin and gradually booms in a cone shape outwards.

A cone-shaped cornea causes blurred vision, which may cause sensitivity to light which glare irritation. Keratoconus usually affects both eyes, and usually first affects people between the ages of 10 and 25. The condition can develop slowly for 10 years or longer.

In the early stages of keratoconus, with glasses or soft contact lenses can correct vision problems. Later, you may have to be fitted with rigid, gas permeable contact lenses or other types of lenses. If your condition is progressing to an advanced stage, a cornea transplant may be required.

WHAT ARE THE SYMPTOMS OF KERATOCONUS?

There are many keratoconus signs from you can find out, including:

• Blurred vision or double vision (especially if it is in one eye only)
• Distortion (near and far) of objects in your vision, including double or triple ‘ghost images’
• Halos (bright rings around a light source), flashing or heavy lights
• Eye swelling
• Eye redness or soreness
• Light sensitivity
• Headaches
• Eyestrain
• The inability to wear contact lenses

If you experience one or more of those symptoms, it might mean that you have keratoconus.

When to seek urgent medical help

See a doctor immediately if you have any of these symptoms or signs:

• Blurred vision
• Eye pain when seeing lights
• Redness of your eyes
• Nausea or vomiting
• Pain in your eye.

What Causes Keratoconus?

Small protein fibers in the skin, called collagen, help hold the cornea in place to prevent it from bulging. When these fibers become weak, the shape cannot be held and the cornea gradually becomes more cone-shaped.

A decrease in protective antioxidants in the cornea causes keratoconus. The corneal cells produce damaging by-products, such as car exhaust. Normally, antioxidants get rid of them and protect the collagen fibers. When the levels of antioxidants are small, the collagen weakens, and the cornea booms out.

Keratoconus is not necessarily hereditary but often exists in families. If you have it and have children, it’s a good idea to have their eyes checked for it starting at age 10. The condition is advancing faster in people with certain medical problems, including some allergic conditions. It could be related to chronic eye rubbing.

Keratoconus usually starts in the teenage years. Nonetheless, it can start in infancy or people up to about 30 years old. It can happen in people 40 and older, but that’s less common.

The changes in corneal shape can occur quickly or over many years. The changes can result in blurred vision, glare and halos at night, and the streaking of lights.

The changes can either stop at any moment or continue for decades. There is no way to predict how it will progress. Ultimately both eyes are affected in most people who have keratoconus but not necessarily to the same extent. It generally develops first in one eye and then later in the other eye.

The stretched collagen fibers can cause serious scarring with severe keratoconus. When the back of the cornea tears, it will swell and take several months for the swelling to go away. This often causes a large corneal scar.

Risk Factors

• Eye rubbing, associated with atopy
• Sleep apnea
• Connective tissue disorders
• Floppy eyelid syndrome[1]
• Retinitis pigmentosa
• Positive family history

Various Complications of Keratoconus

Complications of keratoconus may include:

• Vision loss that may lead to blindness
• A change in the shape of the eye
• Additional eye problems such as astigmatism

Complications of a corneal transplant may include:

• Surgical wound infection
• Rejection of the transplant
• Secondary glaucoma

Prevention

Generally, keratoconus cannot be prevented. Early intervention can slow symptoms of progression, through:

• Regular and periodical eye tests for all family members above 10 years, mainly for families with keratoconus history and risk factors.
• Avoiding rubbing your eyes due to allergies.
• Keeping your eyes clean, without rubbing them.   
• Warding off any eye irritation.
• Protecting your eyes while swimming and in sports.
• Following the instructions of the doctor, and reporting any noticeable progress immediately.
• Avoid unprescribed drugs, even if advised by a patient with keratoconus.