Keratoconus

In the early stages, keratoconus may have mild symptoms or no symptoms and many people are unaware that they have the condition.

Early symptoms may include:

• Mild blurring of vision
• Increased sensitivity to light
• Distorted vision
• Red, swollen eyes
• Headaches
• Eye pain
• A constant need to rub your eyes

As the condition worsens you may experience:

• Worsening blurred and distorted vision both close up and far away
• Difficulty focusing
• Increased short-sightedness
• Not being able to wear contact lenses
• Frequently needing new prescriptions for glasses
• Seeing halos around lights
• Poor night vision
• Sudden worsening or clouding of vision
• Double vision when using one eye
• Ghost images (monocular polyopia)

The cause of keratoconus is not fully understood. The condition is sometimes more common in families and people with certain medical conditions.

Risk factors for keratoconus include:

• Family history - you are more likely to develop keratoconus if a family member has the condition
• Age - keratoconus is most commonly diagnosed in teenagers and young adults
• Chronic eye inflammation - this may be due to allergies or irritants
• Eye rubbing - chronic eye rubbing has been linked to the development of keratoconus and may make the condition worse
• Some medical conditions - such as Down's syndrome, osteogenesis imperfecta, retinitis pigmentosa, asthma, sleep apnoea, Marfan's syndrome and Ehlers-Danlos syndrome

Non-surgical treatment for keratoconus involves glasses or contact lenses to correct vision and, in some cases, reshape your cornea. There are several different types of glasses and contact lenses to treat keratoconus.

Prescription glasses

You may be prescribed glasses if your keratoconus is mild. While these work well to correct your vision in the early stages, you may need to change your prescription frequently and will likely need to use special contact lenses as your condition worsens.

Rigid gas permeable contact lenses

These hard contact lenses allow oxygen to pass through them and help to reshape your cornea. Some people find these lenses uncomfortable in which case a softer contact lens may be placed under the hard lens (piggyback lenses).

Scleral lenses

Scleral lenses are an alternative to rigid gas-permeable lenses and have a liquid layer between the lens and the front of the eye. This layer masks the distortion caused by the abnormal shape of the cornea.

Hybrid lenses

Hybrid lenses are a more comfortable alternative to hard lenses and have a hard centre and a soft ring around the outer edge.

Collagen cross-linking device (CXL)

During this minimally invasive procedure, your consultant applies eyedrops containing vitamin B2 (riboflavin) before using ultraviolet light to strengthen the collagen fibres in the eye. It stops keratoconus from getting worse in around 90% of patients. It is also known as corneal cross-linking.

This treatment is recommended for people with worsening keratoconus or those at high risk of the condition getting worse. You will still need to wear glasses or contact lenses to correct your vision after CXL treatment.

Intracorneal ring segments (Intacs)

During this procedure, two C-shaped plastic rings are inserted into the cornea to flatten and support it. The procedure may improve vision and make wearing contact lenses more comfortable.

Corneal transplant (keratoplasty)

If your keratoconus is severe, your consultant may recommend a corneal transplant. This is a procedure where your corneas are replaced with donor tissue. Your vision will be blurred for three to six months after the surgery, and you will need to take medication to stop your body from rejecting the donor tissue. In most cases, you will need to continue wearing glasses or contact lenses after corneal transplant surgery.

To make a diagnosis, your consultant will perform an extensive eye examination. They may order tests such as:

• Corneal topography - this is the most accurate way to detect early-stage keratoconus and uses a computerised image to map the curve of your cornea. It is also used to measure how fast your condition is progressing
• Slit-lamp exam - in this test, your consultant uses a vertical beam of light and a microscope to examine the outer and middle layers of your cornea
• Keratometry - your consultant uses a circle of light focused on your cornea to determine the shape of your cornea
• Ultrasound pachymetry - uses ultrasound to measure the thickness of the cornea

Your consultant will then make a diagnosis based on your symptoms, medical history, and the results of your eye examination and tests.

Your first appointment is important because it's where we get to know you and discuss your symptoms, general health, and expectations for treatment. Your first appointment is also where you can discuss any concerns or ask any questions you have with your consultant.

At the end of your appointment, your consultant will explain your diagnosis and recommend a suitable treatment.

Can keratoconus be cured?

There is currently no cure for keratoconus, but the condition can usually be managed effectively with treatment.

Is keratoconus rare?

Keratoconus is classified as a rare disease and occurs in around one in two thousand people

Is keratoconus a disability?

In the UK, keratoconus is not classified as a disability as the condition can usually be treated effectively with glasses or contact lenses. In some cases, visual loss due to severe keratoconus may be classed as a disability, but this is decided on a case-by-case basis.

Can keratoconus cause blindness?

Keratoconus does not cause blindness, but it may progress over time and result in blurred or distorted vision that needs to be corrected with glasses or contact lenses.

Can laser eye surgery treat keratoconus?

Laser eye surgery (LASIK) is not recommended for people with keratoconus as it can weaken your cornea and make your vision worse. You should not have LASIK eye surgery even if your keratoconus is mild.

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If you would like to see a consultant or learn more about keratoconus treatment, book your appointment online today or call a member of our team directly on 0141 300 5009.

Content reviewed by Circle in-house team in February 2023. Next review due February 2026.

1. Keratoconus, John Hopkins
2. Keratoconus, RNIB
3. Keratoconus, American Academy of Opthalmology
4. Keratoconus, Cleveland Clinic