Eye diseases

The word keratoconus means cornea with a conical shape.

It's a degenerative disease that causes the cornea (that clear window in the front of the eye) to thin and distort and curve outward. It can affect one or both eyes.

This condition affects one in 1,000 people and manifests in men and women usually between the ages of 10 and 25. It progresses for about 10 years after it declares itself.

Keratoconus affects vision and may not be completely corrected by glasses or soft contact lenses. It is because of this irregular distortion of the cornea that the correction of vision by glasses will be imperfect. For this reason, it is often necessary to resort to other means.

What are the symptoms to watch out for?

Keratoconus can cause several symptoms may include:

  • blurred vision
  • double vision
  • difficulty with vision even when wearing glasses or contact lenses
  • dizziness
  • headache
  • sensitivity to light
  • multiple ghost images around an object
  • difficulty seeing at night

What can be the causes of keratoconus?

The exact causes are currently unknown. However, many studies put forward several hypotheses.

Keratoconus could be hereditary.

Rubbing your eyes regularly can cause thinning of the cornea.

Certain diseases could also be risk factors:

  • certain autoimmune diseases are associated with keratoconus (rheumatoid arthritis, ulcerative colitis, Hashimoto's thyroiditis, asthma, irritable colon syndrome, etc.)
  • allergies
  • eczema
  • lupus
  • Marfan syndrome
  • Sleep Apnea
  • certain mental health disorders (e.g. schizophrenia, etc.)

What are the possible treatments for keratoconus?

Many treatments can be offered depending on the progression of keratoconus.


Glasses or soft contact lenses

More often used in the early stage of keratoconus, it will relieve vision but will not stop the progression of the deformity.


Rigid gas permeable (RGP) contact lenses

This helps present a smooth surface in front of the cornea and improves vision.

However, these lenses can be uncomfortable for some people.


Scleral lenses

These are rigid contact lenses that rest on the white of the eye. Made to measure, the contact lens overhangs the cornea without touching it.

They are generally more comfortable than small rigid lenses.

They are also contact lenses that can be prescribed for dry eyes.


Sometimes, some patients do not tolerate any kind of contact lenses.

Intracorneal rings (Intacs)

These are small plastic pieces implanted in the eye to reshape the cornea and improve vision.

This does not slow the progression of keratoconus.

These rings can become dislodged in the event of a blow to the eye.


Corneal collagen cross-linking (CXL)

It is an intervention to improve the shape of the cornea and stabilize the progression of keratoconus by strengthening the collagen fibers of the cornea.

This consists of administering drops to the cornea followed by low exposure to UVA rays to promote the formation of collagen.

This intervention improves vision and may allow some patients to postpone contact lenses.


Corneal transplant

Over time, keratoconus can lead to corneal damage and require surgery.

Keratoplasty is a corneal transplant from a donor.

Keratoprosthesis is an artificial corneal transplant. It is generally performed after one or more keratoplasty failures.

Can I lose my sight?

Generally we do not lose sight because of keratoconus.


Namely: acute keratoconus corresponds to a tear in Descemet's membrane (one of the layers of the cornea). This causes fluid to leak into the cornea and a sudden drop in vision. With proper care, this resolves within a few months.

Not to be confused with...

Symptoms of keratoconus are similar to other fairly similar conditions and this can be confusing.



The cornea of a person with astigmatism is irregular and not round as it should be. However, in this case there is no thinning of the cornea.


Lenticon and lenticone

These are two types of deformations but which affect the lens.


Pellucid marginal degeneration (PMD)

Here, it is the thinning of specific regions on the sides of the cornea.

It appears between the ages of 20 and 50 and is not hereditary.



It is a condition present from birth and which causes thinning of the peripheral cornea.